High-Throughput Accurate Single-Cell Screening of Euglena gracilis with Fluorescence-Assisted Optofluidic Time-Stretch Microscopy.

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Baoshan Guo

Full Text Available The development of reliable, sustainable, and economical sources of alternative fuels is an important, but challenging goal for the world. As an alternative to liquid fossil fuels, algal biofuel is expected to play a key role in alleviating global warming since algae absorb atmospheric CO2 via photosynthesis. Among various algae for fuel production, Euglena gracilis is an attractive microalgal species as it is known to produce wax ester (good for biodiesel and aviation fuel within lipid droplets. To date, while there exist many techniques for inducing microalgal cells to produce and accumulate lipid with high efficiency, few analytical methods are available for characterizing a population of such lipid-accumulated microalgae including E. gracilis with high throughout, high accuracy, and single-cell resolution simultaneously. Here we demonstrate high-throughput, high-accuracy, single-cell screening of E. gracilis with fluorescence-assisted optofluidic time-stretch microscopy-a method that combines the strengths of microfluidic cell focusing, optical time-stretch microscopy, and fluorescence detection used in conventional flow cytometry. Specifically, our fluorescence-assisted optofluidic time-stretch microscope consists of an optical time-stretch microscope and a fluorescence analyzer on top of a hydrodynamically focusing microfluidic device and can detect fluorescence from every E. gracilis cell in a population and simultaneously obtain its image with a high throughput of 10,000 cells/s. With the multi-dimensional information acquired by the system, we classify nitrogen-sufficient (ordinary and nitrogen-deficient (lipid-accumulated E. gracilis cells with a low false positive rate of 1.0%. This method holds promise for evaluating cultivation techniques and selective breeding for microalgae-based biofuel production.

Diseño de pan con masa madre y microalgas

OpenAIRE

Lara Martínez, Irene Fernán

2015-01-01

[EN] Bread is a food with high consumption in the Spanish population. Demand of different varieties of it is increasing, moreover it has to provide extra health nutritional benefits. For this reason this paper aims to the formulation, preparation and subsequent rating of 4 breads made from 4 sourdough which were incorporated 1.5% of 4 different species of microalgae to each of them: Isochrysis galbana, Tetraselmis suecica, Scenedesmus almeriensis and Nannochloropsis gaditana. ...

Ankistrodesmus gracilis (Chlorophyta fertilized in swine manure in the laboratory

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Lúcia Helena Sipaúba-Tavares

2008-03-01

Full Text Available The objective of the present work was to investigate the influence of swine manure media on the growth, total length, dry weight, and nutritional value of Ankistrodesmus gracilis microalgae. Two media were measured: “in natura” and biodigested. The growth rate peak for A. gracilis was highest with biodigester treatment (6.2 x 107 cells.mL-1 on the 5th day, at a volume of 2L. The highest percentage of lipids was verifi ed for “in natura” media. Protein was highest (p > 0.05 for the biodigested media at 2L. Biovolume, ash rate, and total length were different (p 0.05. Light demand was also different between media, with lesser intensity being required for biodigested media (13.5μE.cm-2.s-1. In fact, the biodigested media proved to be cheaper in terms of cost and benefit. Generally, the medium containing swine manure, both “in natura” and biodigested, showed better results in A. gracilis development, with water quality adequate for culture systems. Swine manure in both forms may also be used in high-density cultures in the laboratory.

Effect of Cadmium on the population growth of the marine diatom Chaetoceros gracilis Schutt

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Giovana Vera

2014-06-01

Full Text Available Phytoplankton constitutes the base of the trophic webs in the marine environment, so it is important to know the possible effects of pollutants on the algal populations. In the present paper the effect of cadmium on the population growth of the diatom Chaetoceros gracilis was assessed. The microalgae were cultured in the a modified “f/2” Guillard medium, and were exposed to different concentrations of cadmium between 50 and 100000 µg.–1, which produced an inhibitory effect from 20% to 99% on the population growth of Chaetoceros gracilis. Based on the dose (cadmium-response (inhibition relationship, a mean effective concentration (EC50% equal to 591 µg.L–1 of cadmium was obtained.

Genotoxicity and subchronic toxicity evaluation of dried Euglena gracilis ATCC PTA-123017.

Science.gov (United States)

Simon, Ryan R; Vo, Trung D; Levine, Robert

2016-10-01

Euglena gracilis is a microalga capable of synthesizing various nutrients of interest in human and animal nutrition. When cultivated aerobically in the dark, Euglena synthesize paramylon, a storage polysaccharide comprised of high molecular weight beta-1,3-D-glucose polymers organized in cytoplasmic granules. Beta-glucans have been shown to have immune modulation effects, including anti-microbial, anti-tumor, and anti-oxidant properties, and metabolic effects, such as regulation of cholesterol and blood sugar levels. Preparations of E. gracilis and paramylon may therefore have potential utility as functional food ingredients for human and animal nutrition. A battery of toxicological studies was conducted on a dried preparation of E. gracilis and paramylon to support their safe food use. The dried alga was not genotoxic in a bacterial reverse mutation test and mammalian micronucleus test. In the subchronic toxicity study, rats were provided E. gracilis in the diet at levels of 0, 12,500, 25,000 or 50,000 ppm. Paramylon was provided at a concentration of 50,000 ppm. No effects that could be attributable to treatment were observed in clinical observations, body weight, food consumption, ophthalmology, hematology and clinical chemistry, urinalysis, and macroscopic and microscopic findings. A NOAEL of 50,000 ppm in the diet was determined for both ingredients. Copyright © 2016 Elsevier Inc. All rights reserved.

Efeito do meio Erd Schreiber no cultivo das microalgas Dunaliella salina, Tetraselmis chuii e Isochrysis galbana = Erd Schreiber medium effect in culture of microalgae Dunaliella salina, Tetraselmis chuii and Isochrysis galbana

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Vera Lucia Mota Klein

2006-04-01

Full Text Available As microalgas são utilizadas como fonte de alimento em aqüicultura. Neste trabalho cultivaram-se D. salina, T. chuii e I. galbana. O objetivo do trabalho consistiu em determinar o efeito do meio Erd Schreiber sobre o seu crescimento. Iniciou-se o cultivo com a mistura de 200 mg de Na2HPO4,7H2O, 100 mg de NaNO3 e 50 mL de extrato de solo. No monitoramento, manteve-se a temperatura entre 24 - 28 oC, a salinidade a 34 ppt, à iluminação constante, a densidade celular com uma câmara de Neubauer e um microscópio binocular modelo ZEISS. Como resultado, I. galbana, D. salina e T. chuii atingiram 969 104 cel/mL, 457 x 104 cel/mL e 258,66 x 104 cel/mL, respectivamente, e oscoeficientes angulares b foram 3,76 x 104 cel./mL/dia, 6,84 x 104 cel./mL/dia e 2,08 x 104 cel./mL/dia respectivamente, indicando bom desempenho de todas as microalgas no meio Erd Shreiber.The microalgae is used as food source in aqüicultura. In this work they had cultivated D. salina , T. chuii and I. galbana . The objective of the work is to determine the effect of Erd Schreiber´s culture medium on the microalgae growth. The culture initiated mixting 200mg of Na2HPO4,7H2O, 100 mg of NaNO3 and 50 mL of soil extract. During the culture the temperature had varied between 24 and 28oC, the salinity was fixed on 34 %o, and the illumination was maintained constant. The assessment of the culture was made by a chamber of Neubauer and a binocular microscope ZEISS model. As result I. galbana D. salina and T.chuii reached 969 104 cel/mL, 457 x 104cel/mL and 258,66 x 104 cel/mL respectively and as angular coefficient 3,76 x 104 cel/mL/dia, 6,84 x 104 cel/mL/dia and 2,08 104 x cel/mL/dia respectively, showing good answer of the microalgae to the effect of Erd Schreiber´ s medium.

Euglena gracilis Z and its carbohydrate storage substance relieve arthritis symptoms by modulating Th17 immunity.

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Kengo Suzuki

Full Text Available Euglena gracilis Z is a microorganism classified as a microalga and is used as a food or nutritional supplement. Paramylon, the carbohydrate storage substance of E. gracilis Z, is reported to affect the immunological system. This study evaluated the symptom-relieving effects of E. gracilis Z and paramylon in rheumatoid arthritis in a collagen-induced arthritis mouse model. The efficacy of both substances was assessed based on clinical arthritis signs, as well as cytokine (interleukin [IL]-17, IL-6, and interferon [IFN]-γ levels in lymphoid tissues. Additionally, the knee joints were harvested and histopathologically examined. The results showed that both substances reduced the transitional changes in the visual assessment score of arthritis symptoms compared with those in the control group, indicating their symptom-relieving effects on rheumatoid arthritis. Furthermore, E. gracilis Z and paramylon significantly reduced the secretion of the cytokines, IL-17, IL-6, and IFN-γ. The histopathological examination of the control group revealed edema, inflammation, cell hyperplasia, granulation tissue formation, fibrosis, and exudate in the synovial membrane, as well as pannus formation and articular cartilage destruction in the femoral trochlear groove. These changes were suppressed in both treatment groups. Particularly, the E. gracilis Z group showed no edema, inflammation, and fibrosis of the synovial membrane, or pannus formation and destruction of articular cartilage in the femoral trochlear groove. Furthermore, E. gracilis Z and paramylon exhibited symptom-relieving effects on rheumatoid arthritis and suppressed the secretion of cytokines IL-17, IL-6, and IFN-γ. These effects were likely mediated by the regulatory activities of E. gracilis Z and paramylon on Th17 immunity. In addition, the symptom-relieving effects of both substances were comparable, which suggests that paramylon is the active component of Euglena gracilis Z.

Growth of microalgae in autotrophic stationary systems

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Paulo Cunha

2008-06-01

Full Text Available In this paper we evaluate the growth of nine marine microalgae species (Nannochloropsis oculata, Thalassiosira pseudonana, Phaeodactylum tricornutum, Isochrysis galbana, Tetraselmis suecica, Tetraselmis chuii, Chaetoceros muelleri, Thalassiosira fluviatilis and Isochrysis sp. and one freshwater species (Chlorella vulgaris under stationary autotrophy conditions, using erlenmeyers fl asks with 800mL of culture medium exposed to constant light intensities providing a photon flux density of about 150μmol.m-2.s-1 and 25±2oC temperature and constant air flow. The experiment was carried out in a controlled environment considering a block delineating randomized over time with three replicates. The Nannochloropsis oculata showed the highest value of maximum cellular density, but with a longer period of time and a lower growth rate. This was probably due to its tiny cell size, demanding a large number of cells per volume to attain its optimum conditions for light, nutrients, water and atmospheric carbon dioxide. In addition, in spite of showing one of the lowest values of maximum cellular density, Thalassiosira fluviatilis was the species that reached its maximum in a short period of time at the highest growth rate. Chlorella vulgaris was the only freshwater species tested and it showed the poorest performance for all the variables analyzed in the current study.

Isolation and evaluation of oil-producing microalgae from subtropical coastal and brackish waters.

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David K Y Lim

Full Text Available Microalgae have been widely reported as a promising source of biofuels, mainly based on their high areal productivity of biomass and lipids as triacylglycerides and the possibility for cultivation on non-arable land. The isolation and selection of suitable strains that are robust and display high growth and lipid accumulation rates is an important prerequisite for their successful cultivation as a bioenergy source, a process that can be compared to the initial selection and domestication of agricultural crops. We developed standard protocols for the isolation and cultivation for a range of marine and brackish microalgae. By comparing growth rates and lipid productivity, we assessed the potential of subtropical coastal and brackish microalgae for the production of biodiesel and other oil-based bioproducts. This study identified Nannochloropsis sp., Dunaniella salina and new isolates of Chlorella sp. and Tetraselmis sp. as suitable candidates for a multiple-product algae crop. We conclude that subtropical coastal microalgae display a variety of fatty acid profiles that offer a wide scope for several oil-based bioproducts, including biodiesel and omega-3 fatty acids. A biorefinery approach for microalgae would make economical production more feasible but challenges remain for efficient harvesting and extraction processes for some species.

Produção de biomassa e teores de carbono, hidrogênio, nitrogênio e proteína em microalgas Production of biomass and carbon, hydrogen, nitrogen and protein contents in microalgae

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Silvana Ohse

2009-09-01

Full Text Available O aumento da emissão de CO2 e de outros gases efeito estufa tem gerado debates em nível mundial sobre alterações climáticas e estimulado o desenvolvimento de estratégias mitigadoras. Trabalhos nessa área incluem sequestro de CO2 por meio da produção de microalgas aquáticas. Por essa razão, desenvolveu-se um estudo visando determinar os teores de carbono, hidrogênio, nitrogênio e proteína e a produção de biomassa seca de nove espécies de microalgas marinhas (Nannochloropsis oculata, Thalassiosira pseudonana, Phaeodactylum tricornutum, Isochrysis galbana, Tetraselmis suecica, Tetraselmis chuii Chaetoceros muelleri, Thalassiosira fluviatilis e Isochrysis sp. e uma de água doce (Chlorella vulgaris, em cultivo autotrófico estacionário com objetivo de identificar as mais produtivas e com maior capacidade de fixação de carbono. O experimento foi desenvolvido em sala de cultivo, na Universidade Federal de Santa Catarina, com iluminação contínua e radiação em torno de 150µmol m-2 s-1, temperatura de 25±2°C, suplementação de ar constante, sendo utilizados erlenmeyers com 800mL de meio de cultura. O delineamento experimental foi de blocos casualizados no tempo com três repetições. As espécies C. vulgaris e T. suecica são menos produtivas. Quando se visa à suplementação alimentar, as espécies C. vulgaris e T. Chuii são consideradas interessantes, uma vez que apresentam altos teores de C, N, H e proteína. As espécies N. Oculata, T. pseudonana e C. vulgaris apresentam altos teores de C, demonstrando alta capacidade de fixação de carbono.The increase of CO2 emission and other gases greenhouse effect, caused global debates about climatic alterations and stimulated the development of mitigative strategies. Researches in this area includes CO2 kidnapping through the aquatic microalgae production. For this reason, a study was developed aiming to determine the production of dry biomass, carbon content, hydrogen

Biomass production of Tetraselmis suecica using seawater with sanguaza

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Juan Silva B.

2011-03-01

Full Text Available The growth of Tetraselmis suecica was evaluated. The experiment was realized using the Response Surface Methodology (RSM with Central Composite Rotational Design (CCRD with two factors, pH and sanguaza/seawater concentration in the range of 7 - 9 and 2 - 5 % (v/v, respectively. The culture media were stirred by bubbling air constantly (0.07 L/s and continuously illuminated with 40 W of fluorescent light in glass containers of 1.5 L capacity at a temperature of 22.5 ± 2.1 °C. Using the Gompertz mathematical model was determined that from an 8.0 of pH and a ratio of 3.5% of sanguaza/seawater, the Tetraselmis suecica achieves maximum growth. An 8.71 of pH and a ratio of 4.56% of sanguaza/seawater allow the Tetraselmis suecica maximum growth (logN/N0 of 0.659, with a 12.3% of prediction error by applying a mathematical model of 2nd order. According to the study, the values obtained in sanguaza/seawater as a culture medium outperformed the traditionally used culture medium (Guillard F/2 with seawater. The results demonstrate the potential use of the sanguaza/seawater medium in scalable studies on pilot scale production of Tetraselmis suecica, with a view to the production of biodiesel

Phylogenetic distribution of roseobacticides in the Roseobacter group and their effect on microalgae

DEFF Research Database (Denmark)

Sonnenschein, Eva C.; Phippen, Christopher Broughton William; Bentzon-Tilia, Mikkel

2018-01-01

not produce roseobacticides, possibly due to a transposable element. TDA-producing Ruegeria and Pseudovibrio did not produce roseobacticides. Addition of roseobacticide-containing bacterial extracts affected the growth of the microalgae Rhodomonas salina, Thalassiosira pseudonana and Emiliania huxleyi, while...... growth of Tetraselmis suecica was unaffected. During co-cultivation, growth of E. huxleyi was initially stimulated by the roseobacticide producer DSM 17395, while the subsequent decline in algal cell numbers during senescence was enhanced. Strain 27-4 that does not produce roseobacticides had no effect...

Cultivo de Ankistrodesmus gracilis (Chlorophyta em laboratório à base de esterco suíno

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Tatiana Betioli Fioresi

2008-01-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2008v21n1p7 O objetivo do presente trabalho foi testar a influência do meio à base de esterco suíno “in natura” e biodigerido, sobre o desenvolvimento, crescimento, comprimento total, peso seco e valor nutricional da microalga Ankistro desmus gracilis. O pico de crescimento para A. gracilis foi maior no meio biodigerido (6,2 x 107 células. mL-1 no volume de 2L. Alta porcentagem de lipídio foi observada no meio “in natura”, e, elevados teores de proteína no meio biodigerido em 2L. O biovolume, teor de cinzas e comprimento total foram diferentes (p 0,05. O requerimento de luz foi diferente entre os meios, com menor intensidade para o esterco biodigerido (13,5μE.cm-2.s-1, indicando menor custo benefício. O meio a base de esterco suíno, mostrou bons resultados para o crescimento de A. gracilis, com qualidade de água adequada para cultivo, podendo ser utilizado para cultura em larga escala.

Influence of microplastics on the toxicity of the pharmaceuticals procainamide and doxycycline on the marine microalgae Tetraselmis chuii.

Science.gov (United States)

Prata, Joana C; Lavorante, Beatriz R B O; B S M Montenegro, Maria da Conceição; Guilhermino, Lúcia

2018-04-01

Microplastics and pharmaceuticals are considered ubiquitous and emergent pollutants of high concern but the knowledge on their effects on primary producers is still limited, especially those caused by mixtures. Thus, the goal of the present study was to investigate if the presence of microplastics (1-5 μm diameter) influences the toxicity of the pharmaceuticals procainamide and doxycycline to the marine microalga Tetraselmis chuii. Bioassays (96 h) to investigate the toxicity of those substances individually and in mixtures (i.e. microplastics-procainamide mixtures and microplastics-doxycycline mixtures) were carried out. Effect criteria were the average specific growth rate (growth rate) and chlorophyll a concentration (chlorophyll). EC 10 , EC 20 and EC 50 were determined. Microplastics alone had no significant effects on growth rate up to 41.5 mg/l, whereas chlorophyll was significantly reduced at 0.9 and 2.1 mg/l of microplastics, but not at higher concentrations. The 96 h EC 50 (growth rate and chlorophyll, respectively) determined for the other bioassays were: 104 and 143 mg/l for procainamide alone; 125 and 31 mg/l for procainamide in the presence of microplastics; 22 and 14 mg/l for doxycycline alone; 11 and 7 mg/l for doxycycline in the presence of microplastics. Significant differences (p microplastics were found for procainamide (chlorophyll), and doxycycline (both parameters). Thus, both pharmaceuticals were toxic to T. chuii in the low ppm range, and microplastics-pharmaceutical mixtures were more toxic than the pharmaceuticals alone. Very high decreases of doxycycline concentrations in test media were found, indicating degradation of the antibiotic. Thus, although the biological results are expressed in relation to doxycycline concentration, the effects were likely caused by a mixture of the parental compound and its degradation products. The concentrations of microplastics and pharmaceuticals tested (low ppm range) are higher

Rapid alkali catalyzed transesterification of microalgae lipids to biodiesel using simultaneous cooling and microwave heating and its optimization.

Science.gov (United States)

Chee Loong, Teo; Idris, Ani

2014-12-01

Biodiesel with improved yield was produced from microalgae biomass under simultaneous cooling and microwave heating (SCMH). Nannochloropsis sp. and Tetraselmis sp. which were known to contain higher lipid species were used. The yield obtained using this novel technique was compared with the conventional heating (CH) and microwave heating (MWH) as the control method. The results revealed that the yields obtained using the novel SCMH were higher; Nannochloropsis sp. (83.33%) and Tetraselmis sp. (77.14%) than the control methods. Maximum yields were obtained using SCMH when the microwave was set at 50°C, 800W, 16h of reaction with simultaneous cooling at 15°C; and water content and lipid to methanol ratio in reaction mixture was kept to 0 and 1:12 respectively. GC analysis depicted that the biodiesel produced from this technique has lower carbon components (<19 C) and has both reasonable CN and IV reflecting good ignition and lubricating properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

Alternativa de biofertilizante como medio de cultivo para el crecimiento poblacional de dos microalgas marinas empleadas en la camaronicultura

OpenAIRE

Guerra Aznay, M.; Pérez Jar, L.; Leal Lorenzo, S.; Jaime Ceballos, B.; Jiménez Cabrera, R.; Pérez Díaz, S.; Bobadilla González, J.

2012-01-01

Con el propósito de evaluar el humus de lombriz roja californiana Eisenia foetida como biofertilizante para el crecimiento poblacional de dos microalgas marinas, fueron cultivadas Tetraselmis tetrathele y Chaetoceros muelleri en agua de mar enriquecida con cuatro diluciones (50; 200; 350 y 500 mL) de extracto líquido de humus. La especie T. tetrathele, cultivada en la dilución de 200 mL, no mostró diferencias con el patrón medio f/2 Guillard para los parámetros: concentración celu...

Peracetic acid is a suitable disinfectant for recirculating fish-microalgae integrated multi-trophic aquaculture systems

DEFF Research Database (Denmark)

Liu, Dibo; Behrens, Sascha; Pedersen, Lars-Flemming

2016-01-01

culture of a marine microalgae Tetraselmis chuii once per day for four days to four PAA productswith differing hydrogen peroxide (H2O2)/PAA proportions at two concentrations (1 and 2 mg L−1PAA).The H2O2solutions at equivalent total peroxide (H2O2+ PAA) concentrations were tested in parallel. Theresults...... show that the growth and photosynthesis of T. chuii were not affected by three of the PAA prod-ucts (Wofasteril®E400, Wofasteril®E250 and Applichem®150) and equivalent H2O2solutions at bothconcentrations. In contrast, Wofasteril®Lspez and an equivalent H2O2solution at both concentrationscaused...... which are effective against these threats, but safe to fish and microalgae. For this purpose,peracetic acid (PAA) is a valid option because it is highly effective against fish pathogens and bacteria atlow concentrations and degrades spontaneously to harmless residues. In the present study, we exposedthe...

Muscle conserving free gracilis transfer (mini-gracilis free flap

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Bibhuti Bhusan Nayak

2012-01-01

Full Text Available Gracilis is a commonly used muscle for free tissue transfer. It is also split into two based on its pedicles and used as two units. Use of distal part as a free flap in isolation has never been described in literature. We describe a technique of harvesting a small unit of gracilis based on its minor pedicle and maintaining the continuity and conserving the major bulk of muscle. Thus, the function of the muscle is preserved and the same is also available for transfer on its major pedicle later, if required.

Un inusual bloom de Tetraselmis sp. en la Bahía de Valparaíso, Chile

OpenAIRE

PIZARRO, MARLENE; ITURRIAGA, RODOLFO; SILVA, ALEJANDRO; GALLEGOS, SONIA

2012-01-01

A bloom of Tetraselmis sp. was observed during the first days of January of 2006 in the Valparaiso Bay (32° 57'S; 71° 33'W), producing green coloration of sea and exclusion of phytoplankton species. Previous blooms of Tetraselmis sp. have not been observed in this bay.

Observations on feeding behaviour and survival rates in the estuarine calanoid copepods Acartia spinicauda and Heliodiaptomus cinctus (Crustacea: Copepoda: Calanoida)

Digital Repository Service at National Institute of Oceanography (India)

Srivastava, Y.; Fernandes, Brenda; Goswami, S.C.; Goswami, U.; Achuthankutty, C.T.

of Tetraselmis gracilis (Chlorophyta) and Skeletonema costatum (Bacillariophyta), whereas, adults of H. cinctus were fed on five different combinations of phytoplankton feed. Total hourly differences in pigment concentrations indicate that A. spinicauda preferred...

Peracetic acid is a suitable disinfectant for recirculating fish-microalgae integrated multi-trophic aquaculture systems

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Dibo Liu

2016-11-01

Full Text Available Integrated multi-trophic aquaculture (IMTA is a promising direction for the sustainable development of aquaculture. Microalgae have good potential to be integrated with recirculating aquaculture systems because they can use the nitrogen excreted from fish and share the same optimal pH value as in aquaculture. As a byproduct, the microalgae biomass can be used for fish feed or biofuel. However, the recirculating fish-microalgae IMTA system is under constant threat from fish pathogens and phytoplankton-lytic bacteria. Therefore, it is necessary to apply proper disinfectants as prophylaxis or treatment which are effective against these threats, but safe to fish and microalgae. For this purpose, peracetic acid (PAA is a valid option because it is highly effective against fish pathogens and bacteria at low concentrations and degrades spontaneously to harmless residues. In the present study, we exposed the culture of a marine microalgae Tetraselmis chuii once per day for four days to four PAA products with differing hydrogen peroxide (H2O2/PAA proportions at two concentrations (1 and 2 mg L−1 PAA. The H2O2 solutions at equivalent total peroxide (H2O2 + PAA concentrations were tested in parallel. The results show that the growth and photosynthesis of T. chuii were not affected by three of the PAA products (Wofasteril® E400, Wofasteril® E250 and Applichem® 150 and equivalent H2O2 solutions at both concentrations. In contrast, Wofasteril® Lspez and an equivalent H2O2 solution at both concentrations caused irreversible culture collapse, photosynthesis dysfunction and irreversible cell damage. In conclusion, PAA products with low proportions of H2O2 are optimal disinfectants for fish-microalgae IMTA systems.

Growth and lipid accumulation of microalgae from fluctuating brackish and sea water locations in South East Queensland – Australia

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Van Thang eDuong

2015-05-01

Full Text Available One challenge constraining the use of microalgae in the food and biofuels industry is growth and lipid accumulation. Microalgae with high growth characteristics are more likely to originate from the local environment. However, to be commercially effective, in addition to high growth microalgae must also have high lipid productivities and contain the desired fatty acids for their intended use. We isolated microalgae from intertidal locations in South East Queensland, Australia with adverse or fluctuating conditions, as these may harbor more opportunistic strains with high lipid accumulation potential. Screening was based on a standard protocol using growth rate and lipid accumulation as well as prioritizing fatty acid profiles suitable for biodiesel or nutraceuticals. Using these criteria, an initial selection of over 50 local microalgae strains from brackish and sea water was reduced to 16 strains considered suitable for further investigation. Among these 16 strains, the ones most likely to be effective for biodiesel feedstock were Nitzschia sp. CP3a, Tetraselmis sp. M8, Cymbella sp. CP2b and Cylindrotheca closterium SI1c, reaching growth rates of up to 0.53 day-1 and lipid productivities of 5.62 µg mL-1day-1. Omega-3 fatty acids were found in some strains such as Nitzschia sp. CP2a, Nitzschia sp. CP3a and Cylindrotheca closterium SI1c. These strains have potential for further research as commercial food supplements.

Effect of biomass concentration on the productivity of Tetraselmis suecica in a pilot-scale tubular photobioreactor using natural sunlight

NARCIS (Netherlands)

Michels, M.H.A.; Slegers, P.M.; Vermue, M.H.; Wijffels, R.H.

2014-01-01

The effect of biomass concentration on the net volumetric productivity, yield on light and nightly biomass loss rate of Tetraselmis suecica was studied using a pilot-scale tubular photobioreactor (PBR) under outdoor light conditions. The net average productivity and yield on light of Tetraselmis

Adaptations in phytoplankton to changing conditions in tropical estuaries

Digital Repository Service at National Institute of Oceanography (India)

Qasim, S.Z.

adaptation in the algae is to counteract the changing light conditions with depth to which they are exposed during their floatation. The green alga Tetraselmis gracilis was found to have a high requirement for phosphorus and this organism occurs...

Parthenogenetic reproduction of Diaphanosoma celebensis (Crustacea: Cladocera). Effect of algae and algal density on survival, growth, life span and neonate production

Digital Repository Service at National Institute of Oceanography (India)

Shrivastava, Y.; Mahambre, G.G.; Achuthankutty, C.T.; Fernandes, Brenda; Goswami, S.C.; Madhupratap, M.

) and Tetraselmis gracilis (Kylin), was determined. Growth was faster in the initial stage with all three diets but slowed down in later life. Increased food concentrations resulted in higher neonate production but reduced the life span of females. However, long...

Anaerobic Coculture of Microalgae with Thermosipho globiformans and Methanocaldococcus jannaschii at 68°C Enhances Generation of n-Alkane-Rich Biofuels after Pyrolysis

Science.gov (United States)

Matsuyama, Shigeru; Igarashi, Kensuke; Utsumi, Motoo; Shiraiwa, Yoshihiro; Kuwabara, Tomohiko

2013-01-01

We tested different alga-bacterium-archaeon consortia to investigate the production of oil-like mixtures, expecting that n-alkane-rich biofuels might be synthesized after pyrolysis. Thermosipho globiformans and Methanocaldococcus jannaschii were cocultured at 68°C with microalgae for 9 days under two anaerobic conditions, followed by pyrolysis at 300°C for 4 days. Arthrospira platensis (Cyanobacteria), Dunaliella tertiolecta (Chlorophyta), Emiliania huxleyi (Haptophyta), and Euglena gracilis (Euglenophyta) served as microalgal raw materials. D. tertiolecta, E. huxleyi, and E. gracilis cocultured with the bacterium and archaeon inhibited their growth and CH4 production. E. huxleyi had the strongest inhibitory effect. Biofuel generation was enhanced by reducing impurities containing alkanenitriles during pyrolysis. The composition and amounts of n-alkanes produced by pyrolysis were closely related to the lipid contents and composition of the microalgae. Pyrolysis of A. platensis and D. tertiolecta containing mainly phospholipids and glycolipids generated short-carbon-chain n-alkanes (n-tridecane to n-nonadecane) and considerable amounts of isoprenoids. E. gracilis also produced mainly short n-alkanes. In contrast, E. huxleyi containing long-chain (31 and 33 carbon atoms) alkenes and very long-chain (37 to 39 carbon atoms) alkenones, in addition to phospholipids and glycolipids, generated a high yield of n-alkanes of various lengths (n-tridecane to n-pentatriacontane). The gas chromatography-mass spectrometry (GC-MS) profiles of these n-alkanes were similar to those of native petroleum crude oils despite containing a considerable amount of n-hentriacontane. The ratio of phytane to n-octadecane was also similar to that of native crude oils. PMID:23183975

Comparison of Microalgae Cultivation in Photobioreactor, Open Raceway Pond, and a Two-Stage Hybrid System

Energy Technology Data Exchange (ETDEWEB)

Narala, Rakesh R.; Garg, Sourabh; Sharma, Kalpesh K.; Thomas-Hall, Skye R.; Deme, Miklos; Li, Yan; Schenk, Peer M., E-mail: p.schenk@uq.edu.au [Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD (Australia)

2016-08-02

In the wake of intensive fossil fuel usage and CO{sub 2} accumulation in the environment, research is targeted toward sustainable alternate bioenergy that can suffice the growing need for fuel and also that leaves a minimal carbon footprint. Oil production from microalgae can potentially be carried out more efficiently, leaving a smaller footprint and without competing for arable land or biodiverse landscapes. However, current algae cultivation systems and lipid induction processes must be significantly improved and are threatened by contamination with other algae or algal grazers. To address this issue, we have developed an efficient two-stage cultivation system using the marine microalga Tetraselmis sp. M8. This hybrid system combines exponential biomass production in positive pressure air lift-driven bioreactors with a separate synchronized high-lipid induction phase in nutrient deplete open raceway ponds. A comparison to either bioreactor or open raceway pond cultivation system suggests that this process potentially leads to significantly higher productivity of algal lipids. Nutrients are only added to the closed bioreactors, while open raceway ponds have turnovers of only a few days, thus reducing the issue of microalgal grazers.

Comparison of Microalgae Cultivation in Photobioreactor, Open Raceway Pond, and a Two-Stage Hybrid System

International Nuclear Information System (INIS)

Narala, Rakesh R.; Garg, Sourabh; Sharma, Kalpesh K.; Thomas-Hall, Skye R.; Deme, Miklos; Li, Yan; Schenk, Peer M.

2016-01-01

In the wake of intensive fossil fuel usage and CO 2 accumulation in the environment, research is targeted toward sustainable alternate bioenergy that can suffice the growing need for fuel and also that leaves a minimal carbon footprint. Oil production from microalgae can potentially be carried out more efficiently, leaving a smaller footprint and without competing for arable land or biodiverse landscapes. However, current algae cultivation systems and lipid induction processes must be significantly improved and are threatened by contamination with other algae or algal grazers. To address this issue, we have developed an efficient two-stage cultivation system using the marine microalga Tetraselmis sp. M8. This hybrid system combines exponential biomass production in positive pressure air lift-driven bioreactors with a separate synchronized high-lipid induction phase in nutrient deplete open raceway ponds. A comparison to either bioreactor or open raceway pond cultivation system suggests that this process potentially leads to significantly higher productivity of algal lipids. Nutrients are only added to the closed bioreactors, while open raceway ponds have turnovers of only a few days, thus reducing the issue of microalgal grazers.

Comparison of microalgae cultivation in photobioreactor, open raceway pond, and a two-stage hybrid system

Directory of Open Access Journals (Sweden)

Rakesh R Narala

2016-08-01

Full Text Available In the wake of intensive fossil fuel usage and CO2 accumulation in the environment, research is targeted towards sustainable alternate bioenergy that can suffice the growing need for fuel and also that leaves a minimal carbon footprint. Oil production from microalgae can potentially be carried out more efficiently, leaving a smaller footprint and without competing for arable land or biodiverse landscapes. However, current algae cultivation systems and lipid induction processes must be significantly improved and are threatened by contamination with other algae or algal grazers. To address this issue, we have developed an efficient two-stage cultivation system using the marine microalga Tetraselmis sp. M8. This hybrid system combines exponential biomass production in positive pressure air lift-driven bioreactors with a separate synchronized high-lipid induction phase in nutrient deplete open raceway ponds. A comparison to either bioreactor or open raceway pond cultivation system suggests that this process potentially leads to significantly higher productivity of algal lipids. Nutrients are only added to the closed bioreactors while open raceway ponds have turnovers of only a few days, thus reducing the issue of microalgal grazers.

Thermogravimetric study of the combustion of Tetraselmis suecica microalgae and its blend with a Victorian brown coal in O2/N2 and O2/CO2 atmospheres.

Science.gov (United States)

Tahmasebi, Arash; Kassim, Mohd Asyraf; Yu, Jianglong; Bhattacharya, Sankar

2013-12-01

The combustion characteristics of microalgae, brown coal and their blends under O2/N2 and O2/CO2 atmospheres were studied using thermogravimetry. In microalgae combustion, two peaks at 265 and 485°C were attributable to combustion of protein and carbohydrate with lipid, respectively. The DTG profile of coal showed one peak with maximum mass loss rate at 360°C. Replacement of N2 by CO2 delayed the combustion of coal and microalgae. The increase in O2 concentration did not show any effect on combustion of protein at the first stage of microalgae combustion. However, between 400 and 600°C, with the increase of O2 partial pressure the mass loss rate of microalgae increased and TG and DTG curves of brown coal combustion shifted to lower temperature zone. The lowest and highest activation energy values were obtained for coal and microalgae, respectively. With increased microalgae/coal ratio in the blends, the activation energy increased due to synergy effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impact of elevated CO2 concentrations on the growth and ultrastructure of non-calcifying marine diatom (Chaetoceros gracilis F.Schütt

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Hanan M. Khairy

2014-01-01

Full Text Available The impacts of different CO2 concentrations on the growth, physiology and ultrastructure of noncalcifying microalga Chaetoceros gracilis F.Schütt (Diatom were studied. We incubated Ch. gracilis under different CO2 concentrations, preindustrial and current ambient atmospheric concentrations (285 and 385 μatm, respectively or predicted year-2100 CO2 levels (550, 750 and 1050 μatm in continuous culture conditions. The growth of Ch. gracilis measured as cell number was decreased by increasing the pCO2 concentration from nowadays concentration (385 μatm to 1050 μatm. The lowest percentage changes of oxidizable organic matter, nitrite, nitrate, phosphate and silicate were recorded at a higher pCO2 (1050 μatm, and this is in consistence with the lowest recorded cell number indicating unsuitable conditions for the growth of Ch. gracilis. The minimum cell numbers obtained at higher levels of CO2 clearly demonstrate that, low improvement occurred when the carbon level was raised. This was confirmed by a highly negative correlation between cell number and carbon dioxide partial pressure (r = −0.742, p ⩽ 0.05. On the other hand, highest growth rate at pCO2 = 385 μatm was also confirmed by the maximum uptake of nutrient salts (NO3 = 68.96 μmol.l−1, PO4 = 29.75 μmol.l−1, Si2O3 = 36.99 μmol.l−1. Total protein, carbohydrate and lipid composition showed significant differences (p ⩽ 0.05 at different carbon dioxide concentrations during the exponential growth phase (day 8. Transmission Electron Microscopy of Ch. gracilis showed enlargement of the cell, chloroplast damage, disorganization and disintegration of thylakoid membranes; cell lysis occurs at a higher CO2 concentration (1050 μatm. It is concluded from this regression equation and from the results that the growth of Ch. gracilis is expected to decrease by increasing pCO2 and increasing ocean acidification.

Experimentacion y Optimizacion Conjunta de la Disrupcion Celular de Microalgas y Extraccion Soxhletde Aceite Para Alimentacion y Biocombustibles

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Angel D González Delgado

2014-03-01

Full Text Available La producción de biocombustibles y bioproductos utilizando microalgas puede realizarse con tratamientos térmicos para producir biocrudo, o mediante la extracción y transformación de metabolitos específicos. Esta última alternativa incluye las etapas de cultivo, cosecha, secado, extracción de lípidos y purificación o transformación de los mismos. La factibilidad técnica y económica de la obtención de bioproductos derivados del aceite de microalgas depende en gran medida de la eficiencia de extracción de los lípidos. El objetivo principal de este trabajo es establecer una metodología para la disrupción celular y extracción soxhlet de aceite de microalgas, y determinar su efectividad en tres cepas nativas; Amphiprora, Desmodesmus y Tetraselmis. Se evaluó el efecto de distintos métodos de disrupción celular como MSA, MHA, HA4M Fast, y HA0.5M Slow,solventes como hexano, ciclohexano y metanol, y tiempos de extracción de 4,6 y 8 horas, sobre la cantidad de aceite extraído. La mayor eficiencia de extracción se obtuvo utilizando disrupción celular MSA. El mejor solvente fue hexano y el mejor tiempo de extracción fue de 8 horas.

Effect of microalgae on intestinal inflammation triggered by soybean meal and bacterial infection in zebrafish.

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Karina Bravo-Tello

Full Text Available Soybean meal has been used in many commercial diets for farm fish; despite this component inducing intestinal inflammation. On the other hand, microalgae have increasingly been used as dietary supplements in fish feed. Nevertheless, the vast quantity of microalgae species means that many remain under- or unstudied, thus limiting wide scale commercial application. In this work, we evaluated the effects to zebrafish (Danio rerio of including Tetraselmis sp (Ts; Phaeodactylum tricornutum (Pt; Chlorella sp (Ch; Nannochloropsis oculata (No; or Nannochloropsis gaditana (Ng as additives in a soybean meal-based diet on intestinal inflammation and survival after Edwardsiella tarda infection. In larvae fed a soybean meal diet supplemented with Ts, Pt, Ch, or Ng, the quantity of neutrophils present in the intestine drastically decreased as compared to larvae fed only the soybean meal diet. Likewise, Ts or Ch supplements in soybean meal or fishmeal increased zebrafish survival by more than 20% after being challenged. In the case of Ts, the observed effect correlated with an increased number of neutrophils present at the infection site. These results suggest that the inclusion of Ts or Ch in fish diets could allow the use of SBM and at the same time improve performance against pathogen.

Effect of enriched Brachionus plicatilis and Artemia salina nauplii by ...

African Journals Online (AJOL)

The growth, developmental stages and survival rates of Sparus aurata larvae fed with Brachionus plicatilis and Artemia salina nauplii enriched by microalga Tetraselmis chuii were studied. Two experiments were carried out; the first concerning with culturing the microalga (T. chuii) in four different media, then using these ...

Campylobacter gracilis and Campylobacter rectus in primary endodontic infections.

Science.gov (United States)

Siqueira, J F; Rôças, I N

2003-03-01

A species-specific nested polymerase chain reaction (PCR) assay was used to investigate the occurrence of Campylobacter gracilis and C. rectus in primary root canal infections. Samples were collected from 57 single-rooted teeth with carious lesions, necrotic pulps and radiographic evidence of periradicular disease. Twenty-eight cases were diagnosed as chronic asymptomatic periradicular lesions, 12 cases as acute apical periodontitis, and 17 cases as acute periradicular abscess. DNA was extracted from the samples and initially amplified using universal 16S rDNA primers. A second round of amplification using the first PCR products was performed to specifically detect C. gracilis or C. rectus in the samples. Campylobacter gracilis and C. rectus were, respectively, detected in 21.4 (6 of 28) and 30% (6 of 20) of the root canals associated with chronic asymptomatic periradicular lesions. Campylobacter gracilis was found in 16.7% (2 of 12) of the cases diagnosed as acute apical periodontitis, whilst C. rectus was found in 33.3% (two of six cases). In the abscessed cases, C. gracilis and C. rectus were detected in 23.5 (4 of 17) and 11.8% (2 of 17) of the cases, respectively. No association of these species with clinical symptoms was observed (P > 0.01) In general, species-specific nPCR allowed the detection of C. gracilis in 21.1% (12 of 57) and C. rectus in 23.3% (10 of 43)of the samples taken from primary endodontic infections. Findings confirmed the assertion that both C. gracilis and C. rectus participate in infections of endodontic origin and suggest a pathogenetic role with regard to periradicular diseases.

Induction of the synthesis of bioactive compounds of the marine alga Tetraselmis tetrathele (West Butcher grown under salinity stress

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Hala Yassin El-Kassas

2016-12-01

Full Text Available This work aims at the induction of the synthesis bioactive compounds in microalgae which are used in aquacultures. Experiments were done using Tetraselmis tetrathele in batch culture for 8 days under different salinity levels. The growth of the alga at salinity 20 ppm was increased by fivefold and synthesis of carotenoids by 20-fold in comparison to the controlled. Increasing NaCl concentration resulted in increasing the fatty acid accumulation in T. tetrathele cells. Saturated fatty acids were the main constituent in the fatty acid methyl esters (FAMEs (3.48 mg/g at salinity 25 ppm. The predominated fatty acids were tridecylic, myristic and pentadecanoic which have potential antimicrobial activities. GC–MS analyses of the alga acetone extract grown under different NaCl concentrations were established. The results showed the presence of 18 bioactive compounds: 9-octadecenamide; in addition to the different esters of some fatty acids: hexanedioic, 1,2-cyclohexanedicarboxylic, phthalic, oleanitrile, hexanedioic and 1,2-cyclohexanedicarboxylic (71.5%; 64.9%; 55.4%; 49.6%; 18.7%; 25.2% and 14.5%, respectively. The study suggested that the alga biosynthesized various bioactive compounds under different salinity levels as defense mechanisms. Accordingly, the growth of T. tetrathele under salinity stress before being used in aquacultures is recommended.

Unusual Bloom of Tetraselmis sp. in the Valparaiso Bay, Chile

Science.gov (United States)

2012-01-01

de Valparaíso, Centro de Investigación y Gestión de los Recursos Naturales , Facultad de Ciencias , Gran Bretaña 1111, Valparaíso, Chile. 2University...RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) 31-05-2013 Journal Article Unusual Bloom of Tetraselmis sp. in the Valparasiso Bay...Invited speaker Classification X U c (X I Journal article (refereed) ( I Oral Presentation, published Journal article (not refereed) Oral Presentation

Pedicularis gracilis Wall. Ex Benth. (Scrophulariaceae Complex in the Himalayas – A Taxonomic Reinvestigation

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Tariq Husain

2003-03-01

Full Text Available The paper highlights the complex nature of Pedicularis gracilis Wall. ex Benth. in the Himalayas and enumerates two subspecies and four varieties of this species. Morphological and distributional data have been appended to show that the subspecies – gracilis and brunoniana (Wall. ex Pennell Husain & Garg and varieties – gracilis and stricta (Wall. Husain & Garg (under subsp. gracilis and brunoniana and macrocarpa (Prain Husain & Garg (under subsp. brunoniana are distinct.

Carrying capacity of Chaetoceros gracilis in Homa Lagoon and the ...

African Journals Online (AJOL)

The possibility for nutrient limitation to affect C. gracilis was assessed from two different ecosystems (Izmir Bay and Homa Lagoon). Our goal was to determine the growth rate of all nutrients and the maximum levels of the C. gracilis phytoplankton biomass (the maximum biomass carrying capacity) on the extent of its full ...

Antibacterial and Antioxidant Activity of Green Algae Halimeda gracilis from Seribu Island District

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Abdul Basir

2017-08-01

Full Text Available Seaweeds have ecological functions as primary producers in marine waters. It also has an important economic value as a producer of hydrocolloids (alginate, agar and carrageenan that is used in various industries of food and pharmaceuticals. This study aimed to determine the antibacterial and antioxidant activity of green algae Halimeda gracilis. The study was conducted in several stages, sample collection and preparation, extraction of bioactive compound, fractionation, antibacterial and antioxidant test, and phytochemical. Extraction was done by maceration method using methanol and concentrated by rotary evaporator. The methanol extracts of H. gracilis were tested against Staphylococcus aureus and Escherichia coli. Methanol extract of H. gracilis formed inhibition zone against the test bacteria with diameter of inhibition zone was 10 mm and 6 mm, respectively. After liquid-liquid partition (water: ethyl acetate, inhibition zone was only seen in the ethyl acetate fraction of H. gracilis with diameter of inhibition zone was 6 mm and 7.50±1.71 mm, respectively. Antioxidant test methanol extracts and ethyl acetate fractions of H. gracilis each show IC50 value of 290.49 ppm and 375.50 ppm. Phytochemical test showed methanol extract of H. gracilis contains phenols and steroids.

Development of virtual photobioreactor for microalgae culture considering turbulent flow and flashing light effect

Energy Technology Data Exchange (ETDEWEB)

Sato, Toru; Hirabayashi, Shinichiro [Department of Ocean Technology, Policy, and Environment, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa 277-8563 (Japan); Yamada, Daiki [Department of Systems Innovation, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8563 (Japan)

2010-06-15

A virtual photobioreactor for mass-culturing microalgae was developed. This is a computer model system combining a numerical simulation code for two-phase turbulent flow of bubbles and continuous medium and a photosynthesis model that can express the flashing light effect. The flashing light effect should be considered because turbulent flow in the reactor gives microalgae a chance to come close to the irradiated surface in the opaque medium at irregular frequency and this intermittent illumination enhances photosynthesis of the algae. The two-phase flow model output the time history of light pass along light ray between the irradiated wall surface of the reactor and the individual algal cell, which was passively moved by turbulent flow. When the history of light intensity, which was calculated from that of the light pass and the Beer-Lambert law, experienced by the cell was given, the photosynthesis model output the amount of O{sub 2} emitted from the cell in every small time interval. Finally, the harvest of the alga was estimated from the amount of the O{sub 2}. As a result, the present model system successfully predicted the algal concentration optimal for the largest O{sub 2} emission at the given light intensity and simulated the growth curve of Chaetoceros gracili. (author)

Development of virtual photobioreactor for microalgae culture considering turbulent flow and flashing light effect

International Nuclear Information System (INIS)

Sato, Toru; Yamada, Daiki; Hirabayashi, Shinichiro

2010-01-01

A virtual photobioreactor for mass-culturing microalgae was developed. This is a computer model system combining a numerical simulation code for two-phase turbulent flow of bubbles and continuous medium and a photosynthesis model that can express the flashing light effect. The flashing light effect should be considered because turbulent flow in the reactor gives microalgae a chance to come close to the irradiated surface in the opaque medium at irregular frequency and this intermittent illumination enhances photosynthesis of the algae. The two-phase flow model output the time history of light pass along light ray between the irradiated wall surface of the reactor and the individual algal cell, which was passively moved by turbulent flow. When the history of light intensity, which was calculated from that of the light pass and the Beer-Lambert law, experienced by the cell was given, the photosynthesis model output the amount of O 2 emitted from the cell in every small time interval. Finally, the harvest of the alga was estimated from the amount of the O 2 . As a result, the present model system successfully predicted the algal concentration optimal for the largest O 2 emission at the given light intensity and simulated the growth curve of Chaetoceros gracili.

Dynamic Penile Corpora Cavernosa Reconstruction Using Bilateral Innervated Gracilis Muscles: A Preclinical Investigation.

Science.gov (United States)

Yin, Zhuming; Liu, Liqiang; Xue, Bingjian; Fan, Jincai; Chen, Wenlin; Liu, Zheng

2018-03-07

Prosthesis-assisted penile reconstruction has been performed extensively to restore a cosmetically acceptable phallus. However, a large number of patients will undergo revision surgery for various prosthesis-related complications. To develop a 1-stage prosthesis-free dynamic cavernosa reconstruction method using bilateral innervated gracilis muscles and to investigate the feasibility and reliability of the surgical design. 10 fresh cadavers were dissected to assess the availability of bilateral gracilis muscles for functional cavernosa rebuilding. 11 mongrel female dogs were involved in the penile reconstruction surgery. The neophallus consisted of bilateral gracilis muscles as the neo-cavernosa, a right gracilis skin flap as the neourethra, and a lower abdominal flap with an anterior rectus sheath as the skin envelope and neo-tunica albuginea. The function and structure of the neo-phalli were assessed 7 months postoperatively. The neurovascular pedicle length of the gracilis muscles and the volume of the gracilis venter musculi were measured in the cadaveric investigation. The average dimensions of the canine neo-phalli at rest and during electrostimulated erection were obtained and the muscular fatigue-resistant curve was drawn. Histologic evaluations also were performed. The neurovascular pedicle length and volume of the gracilis muscles were sufficient to yield a nearly normal appearance of the neo-cavernosa in the cadaveric and animal studies. The muscular fatigue-resistant curve demonstrated adequate length, stiffness, and duration of erection of the neo-phalli to accomplish normal coitus. Histologic evaluations showed an intact neourethra and nearly normal muscle structure in the inner layer of the canine neo-cavernosa, except for significantly increased amount of collagen fibers and type I/III collagen ratio in the outer layer of the neo-cavernosa. The percentage of type II (fatigue-prone) muscle fibers did not change significantly. Our preclinical

Trophic transfer of gold nanoparticles from Euglena gracilis or Chlamydomonas reinhardtii to Daphnia magna

International Nuclear Information System (INIS)

Lee, Woo-Mi; Yoon, Sung-Ji; Shin, Yu-Jin; An, Youn-Joo

2015-01-01

Understanding the trophic transfer of nanoparticles (NPs) is important because NPs are small enough to easily penetrate into organisms. In this study, we evaluated the trophic transfer of gold NPs (AuNPs) within the aquatic food chain. We observed AuNPs transfer from 2 species of primary producers (Chlamydomonas reinhardtii or Euglena gracilis) to the primary consumer (Daphnia magna). Also, bioaccumulation of AuNPs in E. gracilis was higher than that in C. reinhardtii. The reasons for the difference in Au accumulation may be the physical structure of these organisms, and the surface area that is available for interaction with NPs. C. reinhardtii has a cell wall that may act as a barrier to the penetration of NPs. The size of E. gracilis is larger than that of C. reinhardtii. This study demonstrates the trophic transfer of AuNPs from a general producer to a consumer in an aquatic environment. - Highlights: • This study evaluated the trophic transfer of AuNPs in an aquatic food chain. • Chlamydomonas reinhardtii and Euglena gracilis were selected as the primary producers. • Daphnia magna was used as the primary consumer. • The bioaccumulation of AuNPs in E. gracilis was higher than that in C. reinhardtii. • AuNPs were transferred from C. reinhardtii and E. gracilis to D. magna. - Gold nanoparticles can transfer from primary producers (Chlamydomonas reinhardtii or Euglena gracilis) to the primary consumer (Daphnia magna) in an aquatic environment

Antiviral Ability of Kalanchoe gracilis Leaf Extract against Enterovirus 71 and Coxsackievirus A16

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Ching-Ying Wang

2012-01-01

Full Text Available Pandemic infection or reemergence of Enterovirus 71 (EV71 and coxsackievirus A16 (CVA16 occurs in tropical and subtropical regions, being associated with hand-foot-and-mouth disease, herpangina, aseptic meningitis, brain stem encephalitis, pulmonary edema, and paralysis. However, effective therapeutic drugs against EV71 and CVA16 are rare. Kalanchoe gracilis (L. DC is used for the treatment of injuries, pain, and inflammation. This study investigated antiviral effects of K. gracilis leaf extract on EV71 and CVA16 replications. HPLC analysis with a C-18 reverse phase column showed fingerprint profiles of K. gracilis leaf extract had 15 chromatographic peaks. UV/vis absorption spectra revealed peaks 5, 12, and 15 as ferulic acid, quercetin, and kaempferol, respectively. K. gracilis leaf extract showed little cytotoxicity, but exhibited concentration-dependent antiviral activities including cytopathic effect, plaque, and virus yield reductions. K. gracilis leaf extract was shown to be more potent in antiviral activity than ferulic acid, quercetin, and kaempferol, significantly inhibiting in vitro replication of EV71 (IC50=35.88 μg/mL and CVA16 (IC50=42.91 μg/mL. Moreover, K. gracilis leaf extract is a safe antienteroviral agent with the inactivation of viral 2A protease and reduction of IL-6 and RANTES expressions.

Antiviral Ability of Kalanchoe gracilis Leaf Extract against Enterovirus 71 and Coxsackievirus A16

Science.gov (United States)

Wang, Ching-Ying; Huang, Shun-Chueh; Zhang, Yongjun; Lai, Zhen-Rung; Kung, Szu-Hao; Chang, Yuan-Shiun; Lin, Cheng-Wen

2012-01-01

Pandemic infection or reemergence of Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) occurs in tropical and subtropical regions, being associated with hand-foot-and-mouth disease, herpangina, aseptic meningitis, brain stem encephalitis, pulmonary edema, and paralysis. However, effective therapeutic drugs against EV71 and CVA16 are rare. Kalanchoe gracilis (L.) DC is used for the treatment of injuries, pain, and inflammation. This study investigated antiviral effects of K. gracilis leaf extract on EV71 and CVA16 replications. HPLC analysis with a C-18 reverse phase column showed fingerprint profiles of K. gracilis leaf extract had 15 chromatographic peaks. UV/vis absorption spectra revealed peaks 5, 12, and 15 as ferulic acid, quercetin, and kaempferol, respectively. K. gracilis leaf extract showed little cytotoxicity, but exhibited concentration-dependent antiviral activities including cytopathic effect, plaque, and virus yield reductions. K. gracilis leaf extract was shown to be more potent in antiviral activity than ferulic acid, quercetin, and kaempferol, significantly inhibiting in vitro replication of EV71 (IC50 = 35.88 μg/mL) and CVA16 (IC50 = 42.91 μg/mL). Moreover, K. gracilis leaf extract is a safe antienteroviral agent with the inactivation of viral 2A protease and reduction of IL-6 and RANTES expressions. PMID:22666293

Greenalgae as a substrate for biogas production - cultivation and biogas potentials

OpenAIRE

Liu, Yang

2010-01-01

Algae is regarded as a good potential substrate for biogas production, due to high cells productivity, low cellulose and zero lignin content. Two parts were included in this study: first, cultivations of micro-algae (Chlorella sorokiniana and Tetraselmis suecica) at two different nitrate concentrations, also the effect of addition of CO2 on algae grow was investigated in this first part. Second, batch fermentations of the cultivated micro-algae as well as a powder Chlorella (obtained from Raw...

Microalgae: biofuel production

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Babita Kumari

2013-04-01

Full Text Available In the present day, microalgae feedstocks are gaining interest in energy scenario due to their fast growth potential coupled with relatively high lipid, carbohydrate and nutrients contents. All of these properties render them an excellent source for biofuels such as biodiesel, bioethanol and biomethane; as well as a number of other valuable pharmaceutical and nutraceutical products. The present review is a critical appraisal of the commercialization potential of microalgae biofuels. The available literature on various aspects of microalgae for e.g. its cultivation, life cycle assessment, and conceptualization of an algal biorefinery, has been done. The evaluation of available information suggests the operational and maintenance cost along with maximization of oil-rich microalgae production is the key factor for successful commercialization of microalgae-based fuels.

Effect of UV-B radiation on the fatty acid composition of the marine phytoplankter Tetraselmis sp.: Relationahip to cellular pigments

Digital Repository Service at National Institute of Oceanography (India)

Goes, J.I.; Handa, N.; Taguchi, S.; Hama, T.

values or the values of fatty ac~ds recorded when the treated samples were returned to control conditions. Variance ratios (F) presented in Table 4 Goes et a1 Effect of UV-B radiation on Tetraselmis fatty acid compos~tion 267 -- Table 3...

Desenvolvimento marsupial e pós-marsupial de Janaira Gracilis (Crustacea, Isopoda, Asellota Marsupial and postmarsupial development of Janaira gracilis

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Ana Maria Setubal Pires

1977-01-01

Full Text Available No presente estudo são descritos os estádios de desenvolvimento de Janaira gracilis e discutidos vários aspectos de seu crescimento. Coletou-se o material mensalmente, de janeiro de 1972 a janeiro de 1973, junto ao trapiche da Base Norte do Instituto Oceanográfico da Universidade de São Paulo, Ubatuba, Estado de Sao Paulo. Janaira gracilis apresenta 4 estádios de desenvolvimento marsupial, 9 de desenvolvimento pós-marsupial para as fêmeas, e 10 para os machos. Os estádios pós-marsupiais podem ser bem determinados através do número de artículos do flagelo da antena 1, pereópodo I e VII, pleópodos 1 e 2 masculino e desenvolvimento de oostégitos na fêmea. As transformações decorrentes do desenvolvimento pós-marsupial são mais marcantes nos machos, pois as fêmeas conservam uma morfologia juvenil e uniforme durante toda a sua vida. O crescimento médio dos machos suplanta o das fêmeas a partir do estádio 7. Nestas, a diminuição de crescimento observada deve-se, provavelmente, à utilização crescente de energia disponível, para fins reprodutivos. Os machos alcançam a maturidade sexual precocemente às fêmeas.The development and growth of Janaira gracilis are described and discussed. The sampling was carried out once a month from January 1972 to January 1973 at the pier of Base Norte, Instituto Oceanográfico USP, Ubatuba, State of São Paulo. Four distinct marsupial stages were disclosed in the development of Janaira gracilis as well as 9 distinct postmarsupial stages for the females and 10 for the males. Every postmarsupial instar can be distinguished by morphological features, such as first antennae articles, first and seventh pereopod, first and second pair of pleopods and the oostegites. During the course of development females undergo less morphological changes than males. Considering the final stages, in average males are larger than females. It is suggested that the decrease in growth of females may be related to

Effects of TiO2 nanoparticles and sunscreens on coastal marine microalgae: Ultraviolet radiation is key variable for toxicity assessment.

Science.gov (United States)

Sendra, M; Sánchez-Quiles, D; Blasco, J; Moreno-Garrido, I; Lubián, L M; Pérez-García, S; Tovar-Sánchez, A

2017-01-01

Given the large numbers of sunbathers on beaches, sunscreen compounds are being released into the coastal aquatic environment in significant amounts. Until now the effect of these potential pollutants on microbiota has been not well-known. Phytoplankton is a key component of the microbiota community. It forms the basis of the aquatic trophic networks, and any change in the natural population of phytoplankton can affect the structure of aquatic biota. This paper describes an experiment performed outdoors (in natural sunlight conditions including ultraviolet radiation (UVR) and with UVR blocked) on mixed microalgae populations (four species from different key marine taxonomic groups, Nannochloropsis gaditana, Chaetoceros gracilis, Pleurochrysis roscoffensis and Amphidinium carterae), for three days, exposed to a range of concentrations of three commercial sunscreens (with variable TiO 2 concentrations: highest concentration for sunscreen C, followed by sunscreen A; and sunscreen B did not contain TiO 2 in its composition). With regard to UVR effect, in the absence of sunscreens, the most sensitive species is the centric diatom, Chaetoceros gracilis, and the least is Nannochloropsis gaditana; this last species presented the same behavior in the absence of UVR and with high sunscreen concentrations. The toxicity gradient obtained for sunscreens and nanoparticles under UVR is: TiO 2 NPs>Sunscreen C>Sunscreen A>Sunscreen B. The differential sensitivity of microalgae to sunscreens and TiO 2 NPs can produce a change in the dynamics of phytoplankton populations and provoke undesirable ecological effects (such as giving dinoflagellates more prominence). The effects of UVR, commonly neglected in bioassays, could alter the results in important ways and should be considered when performing environmentally-relevant bioassays. The toxicity mediated by hydrogen peroxide production associated with the concentration of TiO 2 NPs cannot be considered the only factor responsible for

Production of biodiesel from microalgae

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Danilović Bojana R.

2014-01-01

Full Text Available In recent years, more attention has been paid to the use of third generation feedstocs for the production of biodiesel. One of the most promising sources of oil for biodiesel production are microalgae. They are unicellular or colonial photosynthetic organisms, with permanently increasing industrial application in the production of not only chemicals and nutritional supplements but also biodiesel. Biodiesel productivity per hectare of cultivation area can be up to 100 times higher for microalgae than for oil crops. Also, microalgae can grow in a variety of environments that are often unsuitable for agricultural purposes. Microalgae oil content varies in different species and can reach up to 77% of dry biomass, while the oil productivity by the phototrophic cultivation of microalgae is up to 122 mg/l/d. Variations of the growth conditions and the implementation of the genetic engineering can induce the changes in the composition and productivity of microalgal oil. Biodiesel from microalgae can be produced in two ways: by transesterification of oil extracted from biomass or by direct transesterification of algal biomass (so called in situ transesterification. This paper reviews the curent status of microalgae used for the production of biodiesel including their isolation, cultivation, harvesting and conversion to biodiesel. Because of high oil productivity, microalgae will play a significant role in future biodiesel production. The advantages of using microalgae as a source for biofuel production are increased efficiency and reduced cost of production. Also, microalgae do not require a lot of space for growing and do not have a negative impact on the global food and water supplies. Disadvantages of using microalgae are more difficult separation of biomass and the need for further research to develop standardized methods for microalgae cultivation and biodiesel production. Currently, microalgae are not yet sustainable option for the commercial

Chemical Composition Variability of Essential Oils of Daucus gracilis Steinh. from Algeria.

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Benyelles, Batoul; Allali, Hocine; Dib, Mohamed El Amine; Djabou, Nassim; Paolini, Julien; Costa, Jean

2017-06-01

The chemical compositions of 20 Algerian Daucus gracilis essential oils were investigated using GC-FID, GC/MS, and NMR analyses. Altogether, 47 compounds were identified, accounting for 90 - 99% of the total oil compositions. The main components were linalool (18; 12.5 - 22.6%), 2-methylbutyl 2-methylbutyrate (20; 9.2 - 20.2%), 2-methylbutyl isobutyrate (10; 4.2 - 12.2%), ammimajane (47; 2.6 - 37.1%), (E)-β-ocimene (15; 0.2 - 12.8%) and 3-methylbutyl isovalerate (19; 3.3 - 9.6%). The chemical composition of the essential oils obtained from separate organs was also studied. GC and GC/MS analysis of D. gracilis leaves and flowers allowed identifying 47 compounds, amounting to 92.3% and 94.1% of total oil composition, respectively. GC and GC/MS analysis of D. gracilis leaf and flower oils allowed identifying linalool (22.7%), 2-methylbutyl 2-methylbutyrate (18.9%), 2-methylbutyl isovalerate (13.6%), ammimajane (10.4%), 3-methylbutyl isovalerate (10.3%), (E)-β-ocimene (8.4%) and isopentyl 2-methylbutyrate (8.1%) as main components. The chemical variability of the Algerian oil samples was studied using statistical analysis, which allowed the discrimination of three main Groups. A direct correlation between the altitudes, nature of soils and the chemical compositions of the D. gracilis essential oils was evidenced. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Fatty acids composition of 10 microalgal species

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Thidarat Noiraksar

2005-11-01

Full Text Available Fatty acids composition of 10 species of microalgae was determined at the exponential phase and the stationary phase. The microalgae consist of two species of diatoms, Bacillariophyceae, (Nitzschia cf. ovalis, Thalassiosira sp. five species of green microalgae, Prasinophyceae (Tetraselmis sp. and Chlorophyceae, (Dictyosphaerium pulchellum, Stichococcus sp., Chlorella sp., Scenedesmus falcatus and three species of blue green microalgae, Cyanophyceae (Anacystis sp., Synechococcus sp., Synechocystis sp..Medium for culture diatoms and green microalgae was F/2, and BG-11 media was used for Cyanophyceae. The microalgae were cultured beneath light intensity 143 μEm-2s-1, light: dark illustration 12:12 hrs., temperature 28ºC, and salinities 8-30 psu. The microalgae were harvested for analyzing fatty acid by centrivugal machine at 3500 rpm. for 5 min. at temperature 20ºC and stored at -80ºC prior to analysis.Fatty acids composition of microalgae differed from species to species. The majority fatty acids composition of diatoms at the exponential phase and the stationary phase were C16:1n-7 (17.12-31.47% and 28.22-42.02%, C16:0 (13.25-19.61% and 18.83-20.67%, C20:5 n-3 (16.65-26.67% and 11.32-23.68% respectively. The principle fatty acids composition of green microalgae, Prasinophyceae, Tetraselmis sp. were C18:3n-3 (16.17-16.67%, C16:0 (15.33-17.45%, C18:1n-9 (12.25-15.43%, C18:2n-6 (9.66-19.97%. The fatty acids composition of green microalgae, Chlorophyceae, were C18:3 n-3 (20.02-26.49% and 15.35- 30.63%, C16:0 (5.76-17.61% and 11.41-20.03%, C18:2n-6 (4.67-17.54% and 7.48-20.61% respectively. The major amounts of fatty acids content of blue green microalgae were C16:1n-7 (9.28-34.91% and 34.48- 35.04%, C14:0 (13.34-25.96% and 26.69-28.24%, C16:0 (5.89-29.15% and 5.70-16.81% except for Anacystis sp.which had a high amount of C18:3 n-3 (23.18-27.98% but low amount of C14:0 (3.66-4.98%.Bacillariophyceae contained the highest amount of highly unsaturated

Adynamic Graciloplasty With a Pedicled Gracilis Muscle Flap Wrapped Around Bulbar Urethra for Treatment of Male Acquired Urinary Incontinence.

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Guo, Hailin; Sa, Yinglong; Xu, Yuemin; Wang, Lin; Fei, Xiaofang

2016-05-01

To evaluate the efficacy of adynamic gracilis urethral myoplasty with a pedicled gracilis muscle flap wrapped around bulbar urethra for treatment of male acquired urinary incontinence. Twenty-four patients with acquired urinary incontinence (8 after radical prostatectomy, 7 after transurethral resection of the prostate, and 9 after posterior urethroplasty) were included in our study. Eighteen of these patients (75.0%) had mild to moderate urinary incontinence, and 6 (25.0%) had severe urinary incontinence. All patients received adynamic gracilis urethral myoplasty with a pedicled gracilis muscle flap wrapped around bulbar urethra and had a close follow-up. The mean postoperative maximum urethral pressure after the gracilis muscle wrapped around bulbar urethra was significantly higher than that of the preoperative measurements (P urethra can raise the urethral pressure. Adynamic graciloplasty with a pedicled gracilis muscle flap wrapped around bulbar urethra is a safe and effective surgical option in the treatment of male patients with mild to moderate incontinence, but is not suitable for severe incontinence. Copyright © 2016 Elsevier Inc. All rights reserved.

Minimizing the use of fish oil enrichment in live feed by use of a self-enriching calanoid copepod Pseudodiaptomus annandalei

DEFF Research Database (Denmark)

Rayner, Thomas Allan; Hwang, Jiang-Shiou; Hansen, Benni Winding

2017-01-01

annandalei when cultured on Tetraselmis chuii, a relatively HUFA poor microalgae. A 48 h growth trial using newly spawned nauplii revealed adequate daily specific growth (0.31 ± 0.06 d−1) when fed T. chuii. Another seven day trial was conducted where nauplii were cultured to adult stage while fed T. chuii...

Can the gracilis be used to replace the anterior cruciate ligament in the knee? A cadaver study.

Science.gov (United States)

Cavaignac, Etienne; Pailhé, Regis; Murgier, Jérôme; Reina, Nicolas; Lauwers, Frederic; Chiron, Philippe

2014-12-01

The purpose of this study was to evaluate whether a four-strand gracilis-only graft can be used in anterior cruciate ligament (ACL) reconstruction. Cadaver study. This study involved 16 cadaver knees. The length and diameter of the native ACL were measured in each one. The same measurements were performed on a four-strand graft of the gracilis only, the semitendinosus only and both tendons. Student's t-test was used to compare the various conditions. The average diameter of the G4 construct was 0.07 mm greater (1%) than the native ACL (p=0.044). The average cross-sectional area of the G4 construct was 1.2 mm(2) greater (3.9%) than the native ACL (p=0.049). The G4 was on average 38.9 mm longer than the intra-articular portion of the ACL (p<0.001). A four-strand gracilis construct meets the anatomical specifications for use as an ACL reconstruction graft. By using the gracilis only, the morbidity associated with harvesting the gracilis and semitendinosus tendons should be reduced. Further studies must be performed to compare the biomechanical properties of this graft with other graft types and also to evaluate how this four-strand gracilis graft behaves in a clinical setting. Copyright © 2014 Elsevier B.V. All rights reserved.

Factors affecting growth of the spiny lobsters Panulirus gracilis and Panulirus inflatus (Decapoda: Palinuridae in Guerrero, México

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Patricia Briones-Fourzán

2003-03-01

Full Text Available The effects of sex, injuries, season and site on the growth of the spiny lobsters Panulirus gracilis, and P. inflatus, were studied through mark-recapture techniques in two sites with different ecological characteristics on the coast of Guerrero, México. Panulirus gracilis occurred in both sites, whereas P. inflatus occurred only in one site. All recaptured individuals were adults. Both species had similar intermolt periods, but P. gracilis had significantly higher growth rates (mm carapace length week -1 than P. inflatus as a result of a larger molt increment. Growth rates of males were higher than those of females in both species owing to larger molt increments and shorter intermolt periods in males. Injuries had no effect on growth rates in either species. Individuals of P. gracilis grew faster in site 1 than in site 2. Therefore, the effect of season on growth of P. gracilis was analyzed separately in each site. In site 2, growth rates of P. gracilis were similar in summer and in winter, whereas insite 1 both species had higher growth rates in winter than in summer. This could be due to spatial differences in processes related to changes in population density and food resources, which were documented in previous works. The overall results show that P. gracilis grows faster than P. inflatus, and that growth rates of both species are highly variable and are affected by environmental factors such as site and season, which should be taken into account when attempting to produce population growth curves for each species.Se analizaron, por medio de marcado-recaptura, los efectos del sexo, heridas, estación del año y localidad sobre el crecimiento de las langostas espinosas Panulirus gracilis Streets, 1871, y Panulirus inflatus (Bouvier, 1895 en dos localidades con diferentes características ecológicas en la costa de Guerrero, México. Panulirus gracilis se presentó en ambas localidades, mientras que P. inflatus sólo se encontró en una de

Exploring the glycans of Euglena gracilis

DEFF Research Database (Denmark)

O’Neill, Ellis C.; Kuhaudomlarp, Sakonwan; Rejzek, Martin

2017-01-01

Euglena gracilis is an alga of great biotechnological interest and extensive metabolic capacity, able to make high levels of bioactive compounds, such as polyunsaturated fatty acids, vitamins and β-glucan. Previous work has shown that Euglena expresses a wide range of carbohydrate-active enzymes,...

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African Journals Online (AJOL)

Items 3601 - 3650 of 11090 ... P Mwaura, T Dubois, T Losenge, D Coyne, E Kahangi. Vol 11, No 2 (2012), Effect of enriched Brachionus plicatilis and Artemia salina nauplii by microalga Tetraselmis chuii (Bütcher) grown on four different culture media on the growth and survival of Sparus aurata larvae, Abstract PDF. HM Khairy ...

Evaluation of the analgesic and anti-inflammatory effects of the essential oil of Lippia gracilis leaves.

Science.gov (United States)

Mendes, S S; Bomfim, R R; Jesus, H C R; Alves, P B; Blank, A F; Estevam, C S; Antoniolli, A R; Thomazzi, S M

2010-06-16

The aim of the present study is to investigate the antinociceptive, anti-inflammatory, and antioxidant activities of essential oil (EO) of Lippia gracilis Schauer (Verbenaceae) leaves to support the medicinal uses claimed by folklore practitioners in the caatinga region (semi-arid) of Northeastern Brazil. The chemical composition and antinociceptive and anti-inflammatory activities of the EO of Lippia gracilis leaves (50-200 mg/kg) were investigated. Antinociceptive activity of the EO was evaluated by writhing test. Anti-inflammatory activity of the EO was evaluated using paw oedema and peritonitis methods. Oral treatment with the EO of Lippia gracilis leaves elicited inhibitory activity on acetic acid effect at 50, 100, and 200 mg/kg (30.33+/-2.36, 25.20+/-1.48, and 21.00+/-1.54 abdominal writhes, respectively, Pleaves at 200 mg/kg (0.72+/-0.06 mL h, Pleaves at 50, 100, and 200 mg/kg (13.81+/-0.61, 11.77+/-0.91, and 10.30+/-0.60 leukocytes x 10(6)/mL, respectively, Pessential oil allowed the identification of Lippia gracilis as a thymol-p-cymene chemotype (32.68% and 17.82%, respectively). The EO of Lippia gracilis leaves shows antinociceptive and anti-inflammatory activities. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Antioxidant, anti-inflammatory and antiproliferative activities of Kalanchoe gracilis (L.) DC stem.

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Lai, Zhen-Rung; Ho, Yu-Ling; Huang, Shun-Chieh; Huang, Tai-Hung; Lai, Shang-Chih; Tsai, Jen-Chieh; Wang, Ching-Ying; Huang, Guan-Jhong; Chang, Yuan-Shiun

2011-01-01

Oxidative stress and inflammation are related to several chronic diseases including cancer and atherosclerosis. Kalanchoe gracilis (L.) DC is a special folk medicinal plant in Taiwan. The aim of this study was to evaluate the antioxidant, anti-inflammatory and antiproliferative activities of the methanolic extract and fractions of the stem of K. gracilis. TEAC, total phenolic compound content, total flavonoid content, DPPH radical scavenging activity, reducing power, inhibition of NO production in LPS-induced RAW264.7 cells, and inhibition of cancer cell proliferation were analyzed. Among all fractions, the chloroform fraction showed the highest TEAC and DPPH radical scavenging activities. The chloroform fraction also had the highest content of polyphenols and flavonoids. Chloroform fractions also decreased LPS-induced NO production and expressions of iNOS and COX-2 in RAW264.7 cells. The antiproliferative activities of the methanolic extract and fractions were studied in vitro using HepG2 cells, and the results were consistent with their antioxidant capacities. Chloroform fractions had the highest antiproliferative activity with an IC(50) of 136.85 ± 2.32 μg/ml. Eupafolin also had good pharmacological activity in the antioxidant, anti-inflammation and antiproliferative. Eupafolin might be an important bioactive compound in the stem of K. gracilis. The above experimental data indicated that the stem of K. gracilis is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.

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.

Treatment of ischial pressure sores using a modified gracilis myofasciocutaneous flap.

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Lin, Haodong; Hou, Chunlin; Chen, Aimin; Xu, Zhen

2010-04-01

Despite the availability of a variety of flap reconstruction options, ischial pressure sores continue to be the most difficult pressure sores to treat. This article describes a successful surgical procedure for the coverage of ischial ulcers using a modified gracilis myofasciocutaneous flap. From August 2000 to April 2004, 12 patients with ischial sores were enrolled in the study. All patients underwent early aggressive surgical debridement followed by surgical reconstruction with a modified gracilis myofasciocutaneous flap. The follow-up period ranged from 13 to 86 months, with a mean of 44 months. Overall, 91.7% of the flaps (11 of 12) survived primarily. Partial flap necrosis occurred in one patient. Primary wound healing occurred without complications at both the donor and recipient sites in all cases. In one patient, grade II ischial pressure sores recurred 13 months after the operation. There was no recurrence in other 11 patients. A modified gracilis myofasciocutaneous flap provides a good cover for ischial pressure sores. Because it is easy to use and has favorable results, it can be used in the primary treatment for large and deep ischial pressure sores. Copyright Thieme Medical Publishers.

Microalgae Nutraceuticals

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Marcello Nicoletti

2016-08-01

Full Text Available Among the new entries in the food supplements sector, an important place must be assigned to nutraceuticals containing microalgae, nowadays accounting for a large and rapidly expanding market. The marketed products are mainly based on three production strains, i.e., Spirulina and Chlorella, followed at a distance by Klamath. It is a composite situation, since two of them are cyanobacteria and the second one is eukaryotic. The reality is that each presents similarities in shape and appearance concerning the marketed form and several utilizations, and peculiarities that need special attention and adequate studies. First, general information is reported about the current scientific knowledge on each microalga, in particular the nutritional value and properties in prevention and wellbeing. Second, original studies are presented concerning the quality control of marketed products. Quality control is a key argument in nutraceuticals validation. Microalgae are particular organisms that need specific approaches to confirm identity and validate properties. The proposed control of quality is based on microscopic analysis of the morphologic characteristics. The final parts of this paper are dedicated to the need for specificity in uses and claims and to considerations about the future of microalgae in food supplements.

Free gracilis transfer for smile in children: the Massachusetts Eye and Ear Infirmary Experience in excursion and quality-of-life changes.

Science.gov (United States)

Hadlock, Tessa A; Malo, Juan S; Cheney, Mack L; Henstrom, Douglas K

2011-01-01

Free muscle transfer for facial reanimation has become the standard of care in recent decades and is now the cornerstone intervention for dynamic smile reanimation. We sought to quantify smile excursion and quality-of-life (QOL) changes in our pediatric free gracilis recipients following reanimation. We quantified gracilis muscle excursion in 17 pediatric patients undergoing 19 consecutive pediatric free gracilis transplantation operations, using our validated SMILE program, as an objective measure of functional outcome. These were compared against excursion measured the same way in a cohort of 17 adults with 19 free gracilis operations. In addition, we prospectively evaluated QOL outcomes in these children using the Facial Clinimetric Evaluation (FaCE) instrument. The mean gracilis excursion in our pediatric free gracilis recipients was 8.8 mm ± 5.0 mm, which matched adult results, but with fewer complete failures of less than 2-mm excursion, with 2 (11%) and 4 (21%), respectively. Quality-of-life measures indicated statistically significant improvements following dynamic smile reanimation (P = .01). Dynamic facial reanimation using free gracilis transfer in children has an acceptable success rate, yields improved commissure excursion, and improves QOL in the pediatric population. It should be considered first-line therapy for children with lack of a meaningful smile secondary to facial paralysis.

Posteromedial knee friction syndrome: an entity with medial knee pain and edema between the femoral condyle, sartorius and gracilis

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Simeone, F.J.; Huang, Ambrose J.; Chang, Connie Y.; Smith, Maximilian; Bredella, Miriam A.; Torriani, Martin [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Gill, Thomas J. [Boston Sports Medicine and Research Institute, Boston, MA (United States)

2014-12-20

To describe MRI features of an entity consisting of medial knee pain and edema between the posteromedial femoral condyle (PMFC), sartorius and/or gracilis tendons and determine whether reduced tendon-bone distances may account for these findings. We retrospectively identified MRI cases of edema between the PMFC, sartorius and/or gracilis tendons (25 subjects, 26 knees). Two musculoskeletal radiologists independently graded edema and measured the sartorius- and gracilis-PMFC distances and knee flexion angle. Age- and gender-matched subjects with normal knee MRIs (27 subjects, 27 knees) served as controls for measurements. Statistical analyses compared abnormal to control subjects. Sartorius-PMFC and gracilis-PMFC spaces were narrower in abnormal compared to control subjects (1.6 ± 1.0 vs. 2.1 ± 1.2 mm, P = 0.04; 2.3 ± 2.0 vs. 4.6 ± 3.0 mm, P = 0.002, respectively). The knee flexion angle was similar between groups (P > 0.05). In subjects with clinical information, medial knee pain was the main complaint in 58 % (15/26) of abnormal subjects, with 42 % (11/26) having clinical suspicion of medial meniscal tear. Edema between the PMFC, sartorius and/or gracilis was mild in 54 % (14/26), moderate in 35 % (9/26) and severe in 12 % (3/26), and it was most frequent deep to both the sartorius and gracilis (50 %, 13/26). Edema between the PMFC, sartorius and/or gracilis tendons identified on knee MRI may be associated with medial knee pain and may represent a friction syndrome. (orig.)

Posteromedial knee friction syndrome: an entity with medial knee pain and edema between the femoral condyle, sartorius and gracilis.

Science.gov (United States)

Simeone, F Joseph; Huang, Ambrose J; Chang, Connie Y; Smith, Maximilian; Gill, Thomas J; Bredella, Miriam A; Torriani, Martin

2015-04-01

To describe MRI features of an entity consisting of medial knee pain and edema between the posteromedial femoral condyle (PMFC), sartorius and/or gracilis tendons and determine whether reduced tendon-bone distances may account for these findings. We retrospectively identified MRI cases of edema between the PMFC, sartorius and/or gracilis tendons (25 subjects, 26 knees). Two musculoskeletal radiologists independently graded edema and measured the sartorius- and gracilis-PMFC distances and knee flexion angle. Age- and gender-matched subjects with normal knee MRIs (27 subjects, 27 knees) served as controls for measurements. Statistical analyses compared abnormal to control subjects. Sartorius-PMFC and gracilis-PMFC spaces were narrower in abnormal compared to control subjects (1.6 ± 1.0 vs. 2.1 ± 1.2 mm, P = 0.04; 2.3 ± 2.0 vs. 4.6 ± 3.0 mm, P = 0.002, respectively). The knee flexion angle was similar between groups (P > 0.05). In subjects with clinical information, medial knee pain was the main complaint in 58 % (15/26) of abnormal subjects, with 42 % (11/26) having clinical suspicion of medial meniscal tear. Edema between the PMFC, sartorius and/or gracilis was mild in 54 % (14/26), moderate in 35 % (9/26) and severe in 12 % (3/26), and it was most frequent deep to both the sartorius and gracilis (50 %, 13/26). Edema between the PMFC, sartorius and/or gracilis tendons identified on knee MRI may be associated with medial knee pain and may represent a friction syndrome.

Posteromedial knee friction syndrome: an entity with medial knee pain and edema between the femoral condyle, sartorius and gracilis

International Nuclear Information System (INIS)

Simeone, F.J.; Huang, Ambrose J.; Chang, Connie Y.; Smith, Maximilian; Bredella, Miriam A.; Torriani, Martin; Gill, Thomas J.

2015-01-01

To describe MRI features of an entity consisting of medial knee pain and edema between the posteromedial femoral condyle (PMFC), sartorius and/or gracilis tendons and determine whether reduced tendon-bone distances may account for these findings. We retrospectively identified MRI cases of edema between the PMFC, sartorius and/or gracilis tendons (25 subjects, 26 knees). Two musculoskeletal radiologists independently graded edema and measured the sartorius- and gracilis-PMFC distances and knee flexion angle. Age- and gender-matched subjects with normal knee MRIs (27 subjects, 27 knees) served as controls for measurements. Statistical analyses compared abnormal to control subjects. Sartorius-PMFC and gracilis-PMFC spaces were narrower in abnormal compared to control subjects (1.6 ± 1.0 vs. 2.1 ± 1.2 mm, P = 0.04; 2.3 ± 2.0 vs. 4.6 ± 3.0 mm, P = 0.002, respectively). The knee flexion angle was similar between groups (P > 0.05). In subjects with clinical information, medial knee pain was the main complaint in 58 % (15/26) of abnormal subjects, with 42 % (11/26) having clinical suspicion of medial meniscal tear. Edema between the PMFC, sartorius and/or gracilis was mild in 54 % (14/26), moderate in 35 % (9/26) and severe in 12 % (3/26), and it was most frequent deep to both the sartorius and gracilis (50 %, 13/26). Edema between the PMFC, sartorius and/or gracilis tendons identified on knee MRI may be associated with medial knee pain and may represent a friction syndrome. (orig.)

Cadmium removal by Euglena gracilis is enhanced under anaerobic growth conditions

Energy Technology Data Exchange (ETDEWEB)

Santiago-Martínez, M. Geovanni; Lira-Silva, Elizabeth; Encalada, Rusely; Pineda, Erika; Gallardo-Pérez, Juan Carlos [Departamento de Bioquímica, Instituto Nacional de Cardiología (Mexico); Zepeda-Rodriguez, Armando [Facultad de Medicina, UNAM, Mexico City (Mexico); Moreno-Sánchez, Rafael; Saavedra, Emma [Departamento de Bioquímica, Instituto Nacional de Cardiología (Mexico); Jasso-Chávez, Ricardo, E-mail: rjass_cardiol@yahoo.com.mx [Departamento de Bioquímica, Instituto Nacional de Cardiología (Mexico)

2015-05-15

Highlights: • The protist Euglena gracilis had the ability to grow and remove large amounts of Cd{sup 2+} under anaerobic conditions. • High biomass was attained by combination of glycolytic and mitochondrial carbon sources. • Routes of degradation of glucose, glutamate and malate under anaerobic conditions in E. gracilis are described. • Biosorption was the main mechanism of Cd{sup 2+} removal in anaerobiosis, whereas the Cd{sup 2+} intracellularly accumulated was inactivated by thiol-molecules and polyphosphate. - Abstract: The facultative protist Euglena gracilis, a heavy metal hyper-accumulator, was grown under photo-heterotrophic and extreme conditions (acidic pH, anaerobiosis and with Cd{sup 2+}) and biochemically characterized. High biomass (8.5 × 10{sup 6} cells mL{sup −1}) was reached after 10 days of culture. Under anaerobiosis, photosynthetic activity built up a microaerophilic environment of 0.7% O{sub 2}, which was sufficient to allow mitochondrial respiratory activity: glutamate and malate were fully consumed, whereas 25–33% of the added glucose was consumed. In anaerobic cells, photosynthesis but not respiration was activated by Cd{sup 2+} which induced higher oxidative stress. Malondialdehyde (MDA) levels were 20 times lower in control cells under anaerobiosis than in aerobiosis, although Cd{sup 2+} induced a higher MDA production. Cd{sup 2+} stress induced increased contents of chelating thiols (cysteine, glutathione and phytochelatins) and polyphosphate. Biosorption (90%) and intracellular accumulation (30%) were the mechanisms by which anaerobic cells removed Cd{sup 2+} from medium, which was 36% higher versus aerobic cells. The present study indicated that E. gracilis has the ability to remove Cd{sup 2+} under anaerobic conditions, which might be advantageous for metal removal in sediments from polluted water bodies or bioreactors, where the O{sub 2} concentration is particularly low.

Cadmium removal by Euglena gracilis is enhanced under anaerobic growth conditions

International Nuclear Information System (INIS)

Santiago-Martínez, M. Geovanni; Lira-Silva, Elizabeth; Encalada, Rusely; Pineda, Erika; Gallardo-Pérez, Juan Carlos; Zepeda-Rodriguez, Armando; Moreno-Sánchez, Rafael; Saavedra, Emma; Jasso-Chávez, Ricardo

2015-01-01

Highlights: • The protist Euglena gracilis had the ability to grow and remove large amounts of Cd 2+ under anaerobic conditions. • High biomass was attained by combination of glycolytic and mitochondrial carbon sources. • Routes of degradation of glucose, glutamate and malate under anaerobic conditions in E. gracilis are described. • Biosorption was the main mechanism of Cd 2+ removal in anaerobiosis, whereas the Cd 2+ intracellularly accumulated was inactivated by thiol-molecules and polyphosphate. - Abstract: The facultative protist Euglena gracilis, a heavy metal hyper-accumulator, was grown under photo-heterotrophic and extreme conditions (acidic pH, anaerobiosis and with Cd 2+ ) and biochemically characterized. High biomass (8.5 × 10 6 cells mL −1 ) was reached after 10 days of culture. Under anaerobiosis, photosynthetic activity built up a microaerophilic environment of 0.7% O 2 , which was sufficient to allow mitochondrial respiratory activity: glutamate and malate were fully consumed, whereas 25–33% of the added glucose was consumed. In anaerobic cells, photosynthesis but not respiration was activated by Cd 2+ which induced higher oxidative stress. Malondialdehyde (MDA) levels were 20 times lower in control cells under anaerobiosis than in aerobiosis, although Cd 2+ induced a higher MDA production. Cd 2+ stress induced increased contents of chelating thiols (cysteine, glutathione and phytochelatins) and polyphosphate. Biosorption (90%) and intracellular accumulation (30%) were the mechanisms by which anaerobic cells removed Cd 2+ from medium, which was 36% higher versus aerobic cells. The present study indicated that E. gracilis has the ability to remove Cd 2+ under anaerobic conditions, which might be advantageous for metal removal in sediments from polluted water bodies or bioreactors, where the O 2 concentration is particularly low

Estabelecimento de protocolo para micropropagação de Lippia gracilis Schauer Establishment of protocol for Lippia gracilis Schauer micropropagation

Directory of Open Access Journals (Sweden)

M.J.M Marinho

2011-01-01

Full Text Available A espécie Lippia gracilis SCHAUER (Verbenaceae é nativa do Nordeste brasileiro e se destaca pela capacidade de acumular nos tricomas glandulares óleos essenciais com atividade antimicrobiana. Tendo em vista que não constam trabalhos na literatura sobre o estabelecimento in vitro dessa espécie, este trabalho teve como objetivo estabelecer protocolo para micropropagação de L. gracilis. Para tanto, ramos contendo folhas foram coletados de plantas matrizes no habitat natural para a confecção de estacas. Em laboratório, os explantes provenientes do processo de estaquia foram assepticamente tratados e inoculados em meio MS, acrescido de fitorreguladores, com o intuito de se estabelecer a melhor dose para o desenvolvimento dos explantes. Em decorrência de altos níveis de contaminação, avaliou-se o efeito da cefalexina. No entanto, apesar do antibiótico ter apresentado diminuição na contaminação bacteriana, a porcentagem de oxidação foi elevada. Portanto, testou-se o carvão ativado, ácido ascórbico, ácido cítrico e metade dos sais de MS quanto a eficiência no controle da oxidação. Concluiu-se que, o antibiótico na concentração utilizada provocou a oxidação dos explantes e os fitorreguladores, bem como os métodos antioxidantes testados, não apresentaram resultados consistentes para o melhor desenvolvimento dos explantes e controle da oxidação, respectivamente.The species Lippia gracilis Schauer (Verbenaceae is native to Northeastern Brazil and has been important for its ability to accumulate essential oils with antimicrobial activity in the glandular trichomes. Since there are no reports in the literature on the micropropagation of this species, the present work aimed to establish a protocol for L. gracilis micropropagation. Thus, branches containing leaves were collected from plant matrices in their natural habitat to prepare cuttings. In the laboratory, explants from cutting were aseptically treated and inoculated

Airborne Microalgae: Insights, Opportunities, and Challenges

Science.gov (United States)

Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

2016-01-01

Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

Nutrient recycle from defatted microalgae (Aurantiochytrium) with hydrothermal treatment for microalgae cultivation.

Science.gov (United States)

Aida, Taku Michael; Maruta, Ryouma; Tanabe, Yuuhiko; Oshima, Minori; Nonaka, Toshiyuki; Kujiraoka, Hiroki; Kumagai, Yasuaki; Ota, Masaki; Suzuki, Iwane; Watanabe, Makoto M; Inomata, Hiroshi; Smith, Richard L

2017-03-01

Defatted heterotrophic microalgae (Aurantiochytrium limacinum SR21) was treated with high temperature water (175-350°C, 10-90min) to obtain nitrogen and phosphorous nutrients as a water soluble fraction (WS). Yields of nitrogen and phosphorous recovered in WS varied from 38 to 100% and from 57 to 99%, respectively. Maximum yields of nitrogen containing compounds in WS were proteins (43%), amino acids (12%) and ammonia (60%) at treatment temperatures of 175, 250 and 350°C, respectively. Maximum yield of phosphorous in WS was 99% at a treatment temperature of 250°C. Cultivation experiments of microalgae (A. limacinum SR21) using WS obtained at 200 and 250°C showed positive growth. Water soluble fractions from hydrothermal treatment of defatted microalgae are effective nitrogen and phosphorous nutrient sources for microalgae cultivation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Production of biofuels obtained from microalgae

Directory of Open Access Journals (Sweden)

Luis Carlos Fernández-Linares

2012-09-01

Full Text Available A review of the situation of bio-fuels in the world, mainly of biodiesel is made. A comparison among the different raw materials for the synthesis of biodiesel is done and it is emphasized in the production of biodiesel from microalgae. The different fresh and salt water micro-algae in its lipid content and productivity are compared. A review of the process of biosynthesis of lipids in microalgae and how to improve the production of lipids in microalgae is shown. It is discussed the importance of the genetic manipulation to highly lipid-producing microalgae (example: Botryrococuus braunni, Nannochloropsis sp, Noechlorisoleobundans and Nitschia sp.. A study of the advantages and disadvantages of the different systems of cultivation of microalgae is also made. Finally, it is shown a perspective of biofuels from microalgae. Among the main challenges to overcome to produce biodiesel from microalgae are: the cost of production of biomass, which involves the optimization of media, selection and manipulation of strains and photobioreactors design. The processof separation of biomass, the extraction of oils and by-products, the optimization of the process of transesterification, purification and use of by-products must also be considered.

Unexpectedly Streamlined Mitochondrial Genome of the Euglenozoan Euglena gracilis

Czech Academy of Sciences Publication Activity Database

Dobáková, Eva; Flegontov, Pavel; Skalický, Tomáš; Lukeš, Julius

2015-01-01

Roč. 7, č. 12 (2015), s. 3358-3367 ISSN 1759-6653 R&D Projects: GA ČR GA15-21974S Institutional support: RVO:60077344 Keywords : Euglena gracilis * mitochondrial genome * transcription * RNA editing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.098, year: 2015

Free gracilis muscle transfer for smile reanimation after treatment for advanced parotid malignancy.

Science.gov (United States)

Faris, Callum; Heiser, Alyssa; Hadlock, Tessa; Jowett, Nate

2018-03-01

The purpose of this study was to characterize the outcomes of free gracilis muscle transfer for delayed smile reanimation after radical parotidectomy. A retrospective chart review of patients who underwent free gracilis muscle transfer for smile reanimation after radical parotidectomy between 2003 and 2016 was performed. Patient-reported quality of life (Facial Clinimetric Evaluation Scale [FaCE]), physician-reported facial function ("eFACE" facial grading scale), and oral commissure excursion were compared preoperatively and postoperatively. Twelve patients were identified with prior surgery and adjuvant therapy (radiotherapy in 6 cases and chemoradiotherapy in 6 cases). Significant postoperative improvements were demonstrated for ipsilateral commissure excursion with smile (preoperatively: -2.2 mm [SD 2.3 mm] vs postoperatively: 7.9 mm [SD 2.5 mm]; P = .002), with meaningful smile achieved in 11 of 12 cases (91.7%). The average duration of facial paralysis before intervention was 72 months (range 12-204 months). Free gracilis muscle transfer is an option for dynamic smile reanimation in select patients who have undergone treatment for advanced parotid malignancy. © 2017 Wiley Periodicals, Inc.

Efficient recovery of uranium using genetically improved microalgae; Recuperacion eficaz de uranio utilizando microalgas geneticamente mejoradas

Energy Technology Data Exchange (ETDEWEB)

Lopez-Rodas, V.; Gonzalez Conde, E.; Garcia-Balboa, C.

2014-07-01

Although bioaccumulation is an enzymatic process that requires live microalgae bio sorption is based on physicochemical interactions, and it is not necessary that microalgae are alive, whereby dried microalgae biomass achieves the same results. This alternative could represent a new safe and inexpensive way to recover U. (Author)

Multi-Product Microalgae Biorefineries

NARCIS (Netherlands)

Lam, 't G.P.; Vermuë, M.H.; Eppink, M.H.M.; Wijffels, R.H.; Berg, van den C.

2018-01-01

Although microalgae are a promising biobased feedstock, industrial scale production is still far off. To enhance the economic viability of large-scale microalgae processes, all biomass components need to be valorized, requiring a multi-product biorefinery. However, this concept is still too

Advances in editing microalgae genomes

OpenAIRE

Daboussi, Fayza

2017-01-01

There have been significant advances in microalgal genomics over the last decade. Nevertheless, there are still insufficient tools for the manipulation of microalgae genomes and the development of microalgae as industrial biofactories. Several research groups have recently contributed to progress by demonstrating that particular nucleases can be used for targeted and stable modifications of the genomes of some microalgae species. The nucleases include Meganucleases, Zinc Finger nucleases, TAL...

Tetraselmis chuii biomass as a potential feed additive to improve survival and oxidative stress status of Pacific white-leg shrimp Litopenaeus vannamei postlarvae

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Norazira Abdu Rahman

2017-08-01

Full Text Available Abstract Shrimp is an important traded fishery commodity. When subjected to stress, shrimp usually suffers from oxidative stress, which leads to cell injury, senescence, and death. To maintain shrimp good health, performance and production, antioxidant and immune systems are important. Natural antioxidants found in microalgae may be used to increase the cell protection against oxidative damage, being a promising alternative to the carcinogenic synthetic antioxidants. In this study, Tetraselmis chuii was evaluated for its effect on survival, growth and oxidative stress biomarkers on Litopenaeus vannamei postlarvae (PL. The antioxidant properties of the formulated feed with T. chuii inclusion were determined using four antioxidant chemical assays. Meanwhile, the oxidative stress biomarkers on PL were analyzed by hydrogen peroxide, membrane stability and lipid peroxidation assays. Results showed that PL reared on diets supplemented with 50% T. chuii had a significantly higher (P ≤ 0.05 survival (97.6 ± 1.4% and lower oxidative stress in terms of hydrogen peroxide content (10.08 ± 0.4 mM g−1 FW and electrolyte leakage (10.8 ± 0.3%. The result of this study also showed that shrimp PL reared on diets supplemented with microalgal, T. chuii have high resistance to reverse salinity stress test (76.7–100%. However, no significant differences (P ≥ 0.05 were found in the growth and lipid peroxidation. Due to the positive effect on oxidative stress status, survival and resistance to salinity stress, the feeding of L. vannamei PL with diet containing at least 50% of T. chuii is recommended as a natural source of antioxidant for PL.

Phosphopantetheinylation in the green microalgae Chlamydomonas reinhardtii

DEFF Research Database (Denmark)

Sonnenschein, Eva; Pu, Yuan; Beld, Joris

2016-01-01

available microalgal genome data revealed that most green microalgae appear to carry two PPTases forming clusters with each C. reinhardtii PPTase, while microalgae of other divisions carry one or two PPTases and do not cluster in the pattern of the green algal data. This new understanding on the PPTases...... in microalgae shows that microalgae are already primed for biotechnological applications in contrast to other organisms. Thus, microalgae have great potential for metabolic engineering efforts in the realm of biofuel and high-value products including direct engineering of the fatty acid or secondary metabolism...

Microalgae growth on the aqueous phase from Hydrothermal Liquefaction of the same microalgae

NARCIS (Netherlands)

Garcia Alba, Laura; Torri, Cristian; Fabbri, Daniele; Kersten, Sascha R.A.; Brilman, Derk Willem Frederik

2013-01-01

Cultivation of Desmodesmus sp. microalgae in the recycled aqueous phase (AP) recovered after Hydrothermal Liquefaction (HTL) of the same microalgae was studied to evaluate the potential of nutrients recycling. AP dilution ratio was systematically varied, using either water or water enriched with

Microalgae harvesting techniques: A review.

Science.gov (United States)

Singh, Gulab; Patidar, S K

2018-07-01

Microalgae with wide range of commercial applications have attracted a lot of attention of the researchers in the last few decades. However, microalgae utilization is not economically sustainable due to high cost of harvesting. A wide range of solid - liquid separation techniques are available for microalgae harvesting. The techniques include coagulation and flocculation, flotation, centrifugation and filtration or a combination of various techniques. Despite the importance of harvesting to the economics and energy balance, there is no universal harvesting technique for microalgae. Therefore, this review focuses on assessing technical, economical and application potential of various harvesting techniques so as to allow selection of an appropriate technology for cost effectively harvesting of microalgae from their culture medium. Various harvesting and concentrating techniques of microalgae were reviewed to suggest order of suitability of the techniques for four main microalgae applications i.e biofuel, human and animal food, high valued products, and water quality restoration. For deciding the order of suitability, a comparative analysis of various harvesting techniques based on the six common criterions (i.e biomass quality, cost, biomass quantity, processing time, species specific and toxicity) has been done. Based on the order of various techniques vis-a-vis various criteria and preferred order of criteria for various applications, order of suitability of harvesting techniques for various applications has been decided. Among various harvesting techniques, coagulation and flocculation, centrifugation and filtration were found to be most suitable for considered applications. These techniques may be used alone or in combination for increasing the harvesting efficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

Marine Microalgae with Anti-Cancer Properties.

Science.gov (United States)

Martínez Andrade, Kevin A; Lauritano, Chiara; Romano, Giovanna; Ianora, Adrianna

2018-05-15

Cancer is the leading cause of death globally and finding new therapeutic agents for cancer treatment remains a major challenge in the pursuit for a cure. This paper presents an overview on microalgae with anti-cancer activities. Microalgae are eukaryotic unicellular plants that contribute up to 40% of global primary productivity. They are excellent sources of pigments, lipids, carotenoids, omega-3 fatty acids, polysaccharides, vitamins and other fine chemicals, and there is an increasing demand for their use as nutraceuticals and food supplements. Some microalgae are also reported as having anti-cancer activity. In this review, we report the microalgal species that have shown anti-cancer properties, the cancer cell lines affected by algae and the concentrations of compounds/extracts tested to induce arrest of cell growth. We also report the mediums used for growing microalgae that showed anti-cancer activity and compare the bioactivity of these microalgae with marine anticancer drugs already on the market and in phase III clinical trials. Finally, we discuss why some microalgae can be promising sources of anti-cancer compounds for future development.

Yields, photosynthetic efficiencies, and proximate chemical composition of dense cultures of marine microalgae. A subcontract report

Energy Technology Data Exchange (ETDEWEB)

Thomas, W.H.; Seibert, D.L.R.; Alden, M.; Eldridge, P.; Neori, A.

1983-07-01

The yields, photosynthetic efficiencies, and proximate composition of several microalgae were compared in dense cultures grown at light intensities up to 70% sunlight. Yields ranged from 3.4 to 21.7 g dry weight/m/sup 2/ day. The highest yield was obtained with Phaeodactylum; the lowest in Botryococcus cultures. The same species had the highest and lowest efficiencies of utilization of photosynthetically active radiation. In nitrogen-sufficient cells of all but one species, most of the dry weight consisted of protein. Lipid content of all species was 20 to 29%, and carbohydrate content 11 to 23%. Lipid content increased somewhat in N-deficient Phaeodactylum and Isochrysis cells, but decreased in deficient Monallanthus cells. Because the overall dry weight yield was reduced by deficiency, lipid yields did not increase. However, since the carbohydrate content increased to about 65% in N-deficient Dunaliella and Tetraselmis cells, the carbohydrate yield increased. In Phaeodactylum the optimum light intensity was about 40% of full sunlight. Most experimets with this alga included a CUSO/sub 4/ filter to decrease infrared irradiance. When this filter was removed, the yield increased because more red light in the photosynthetically active spectral range was included. These results should prove useful to workers attempting to maximize yields and efficiencies, but additional studies are needed. 69 references, 27 figures, 18 tables.

Amino acids as possible alternative nitrogen source for growth of Euglena gracilis Z in life support systems.

Science.gov (United States)

Richter, P R; Liu, Y; An, Y; Li, X; Nasir, A; Strauch, S M; Becker, I; Krüger, J; Schuster, M; Ntefidou, M; Daiker, V; Haag, F W M; Aiach, A; Lebert, M

2015-01-01

In recent times Euglena gracilis Z was employed as primary producer in closed environmental life-support system (CELSS), e.g. in space research. The photosynthetic unicellular flagellate is not capable of utilizing nitrate, nitrite, and urea as nitrogen source. Therefore, ammonium is supplied as an N-source in the lab (provided as diammonium-dihydrogenphosphate, (NH4)2HPO4) to E. gracilis cultures. While nitrate exerts low toxicity to organisms, ammonium is harmful for many aquatic organisms especially, at high pH-values, which causes the ionic NH4+ (low toxicity) to be partially transformed into the highly toxic ammonia, NH3. In earlier reports, Euglena gracilis was described to grow with various amino acids as sole N-source. Our aim was to investigate alternatives for (NH4)2HPO4 as N-source with lower toxicity for organisms co-cultivated with Euglena in a CELSS. The growth kinetics of Euglena gracilis cultures was determined in the presence of different amino acids (glycine, glutamine, glutamic acid, leucine, and threonine). In addition, uptake of those amino acids by the cells was measured. Cell growth in the presence of glycine and glutamine was quite comparable to the growth in (NH4)2HPO4 containing cultures while a delay in growth was observed in the presence of leucine and threonine. Unlike, aforementioned amino acids glutamate consumption was very poor. Cell density and glutamate concentration were almost unaltered throughout the experiment and the culture reached the stationary phase within 8 days. The data are compared with earlier studies in which utilization of amino acids in Euglena gracilis was investigated. All tested amino acids (glutamate with limitations) were found to have the potential of being an alternative N-source for Euglena gracilis. Hence, these amino acids can be used as a non-toxic surrogate for (NH4)2HPO4. Copyright © 2014 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Carotenoids in Microalgae.

Science.gov (United States)

Henríquez, Vitalia; Escobar, Carolina; Galarza, Janeth; Gimpel, Javier

Carotenoids are a class of isoprenoids synthesized by all photosynthetic organisms as well as by some non-photosynthetic bacteria and fungi with broad applications in food, feed and cosmetics, and also in the nutraceutical and pharmaceutical industries. Microalgae represent an important source of high-value products, which include carotenoids, among others. Carotenoids play key roles in light harvesting and energy transfer during photosynthesis and in the protection of the photosynthetic apparatus against photooxidative damage. Carotenoids are generally divided into carotenes and xanthophyls, but accumulation in microalgae can also be classified as primary (essential for survival) and secondary (by exposure to specific stimuli).In this chapter, we outline the high value carotenoids produced by commercially important microalgae, their production pathways, the improved production rates that can be achieved by genetic engineering as well as their biotechnological applications.

Uptake and internalisation of copper by three marine microalgae: comparison of copper-sensitive and copper-tolerant species.

Science.gov (United States)

Levy, Jacqueline L; Angel, Brad M; Stauber, Jennifer L; Poon, Wing L; Simpson, Stuart L; Cheng, Shuk Han; Jolley, Dianne F

2008-08-29

Although it has been well established that different species of marine algae have different sensitivities to metals, our understanding of the physiological and biochemical basis for these differences is limited. This study investigated copper adsorption and internalisation in three algal species with differing sensitivities to copper. The diatom Phaeodactylum tricornutum was particularly sensitive to copper, with a 72-h IC50 (concentration of copper to inhibit growth rate by 50%) of 8.0 microg Cu L(-1), compared to the green algae Tetraselmis sp. (72-h IC50 47 microg Cu L(-1)) and Dunaliella tertiolecta (72-h IC50 530 microg Cu L(-1)). At these IC50 concentrations, Tetraselmis sp. had much higher intracellular copper (1.97+/-0.01 x 10(-13)g Cu cell(-1)) than P. tricornutum (0.23+/-0.19 x 10(-13)g Cu cell(-1)) and D. tertiolecta (0.59+/-0.05 x 10(-13)g Cu cell(-1)), suggesting that Tetraselmis sp. effectively detoxifies copper within the cell. By contrast, at the same external copper concentration (50 microg L(-1)), D. tertiolecta appears to better exclude copper than Tetraselmis sp. by having a slower copper internalisation rate and lower internal copper concentrations at equivalent extracellular concentrations. The results suggest that the use of internal copper concentrations and net uptake rates alone cannot explain differences in species-sensitivity for different algal species. Model prediction of copper toxicity to marine biota and understanding fundamental differences in species-sensitivity will require, not just an understanding of water quality parameters and copper-cell binding, but also further knowledge of cellular detoxification mechanisms.

Harvesting microalgae by bio-flocculation and autoflocculation

NARCIS (Netherlands)

Salim, S.

2013-01-01

Harvesting in commercial microalgae production plants is generally done by centrifugation, but this requires upto about 50% of the total energy gained from the microalgae. The energy needed for harvesting can be reduced considerably by pre-concentration of the microalgae prior to further dewatering.

Comparison between direct transesterification of microalgae and hydrochar

Directory of Open Access Journals (Sweden)

Vo Thanh Phuoc

2017-07-01

Full Text Available Hydrothermal carbonization (HTC of microalgae is one of processes that can effectively remove moisture from microalgae. In addition, the hydrochar retains most of fatty acids from microalgae feedstock, and the content of fatty acids in hydrochar is doubled. This research concentrates on the comparison between direct transesterification of microalgae and hydrochar. The result shows that the biodiesel yields of hydrochar were higher than those of microalgae at the same reaction conditions due to the higher extraction rate of fatty acids from hydrochar. Finally, the amount of methanol and catalyst which is required for a given amount of microalgae can be reduced to a half through the direct transesterification of hydrochar.

Highly valuable microalgae: biochemical and topological aspects.

Science.gov (United States)

Pignolet, Olivier; Jubeau, Sébastien; Vaca-Garcia, Carlos; Michaud, Philippe

2013-08-01

The past decade has seen a surge in the interest in microalgae culture for biodiesel production and other applications as renewable biofuels as an alternative to petroleum transport fuels. The development of new technologies for the culture of these photosynthetic microorganisms and improved knowledge of their biochemical composition has spurred innovation in the field of high-value biomolecules. These developments are only economically viable if all the microalgae fractions are valorized in a biorefinery strategy. Achieving this objective requires an understanding of microalgae content and the cellular localization of the main biomolecular families in order to develop efficient harvest and sequential recovery technologies. This review summarizes the state of the art in microalgae compositions and topologies using some examples of the main industrially farmed microalgae.

Biotechnological applications of microalgae

OpenAIRE

Wan-Loy Chu

2012-01-01

Microalgae are important biologicalresources that have a wide range of biotechnologicalapplications. Due to their high nutritional value,microalgae such as Spirulina and Chlorella are beingmass cultured for health food. A variety of high-valueproducts including polyunsaturated fatty acids (PUFA),pigments such as carotenoids and phycobiliproteins, andbioactive compounds are useful as nutraceuticals andpharmaceuticals, as well as for industrial applications. Interms of environmental biotechnolo...

Phototrophic pigment production with microalgae

NARCIS (Netherlands)

Mulders, K.J.M.

2014-01-01

Abstract

Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main focus on secondary

Gracilioethers A-C, Antimalarial Metabolites from the Marine Sponge Agelas gracilis

NARCIS (Netherlands)

Ueoka, R.; Nakao, Y.; Kawatsu, S.; Yaegashi, J.; Matsumoto, Y.; Matsunaga, S.; Furihata, K; van Soest, R.W.M.; Fusetani, N.

2009-01-01

Three new antiprotozoan compounds, gracilioethers A−C (1−3), have been isolated from the marine sponge Agelas gracilis. Their structures were elucidated on the basis of spectroscopic and chemical methods. Gracilioethers A−C showed antimalarial activity against Plasmodium falciparum with IC50 values

Magnetically modified microalgae and their applications

Czech Academy of Sciences Publication Activity Database

Šafařík, Ivo; Procházková, G.; Pospíšková, K.; Brányik, T.

2016-01-01

Roč. 36, č. 5 (2016), s. 931-941 ISSN 0738-8551 R&D Projects: GA ČR GA13-13709S; GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : oleaginous chlorella sp * fresh-water microalgae * magnetophoretic separation * high-gradient * harvesting microalgae * alexandrium-fundyense * polymer binder * algal blooms * cells * removal * Harvesting algal cells * magnetic labeling * magnetic modification * magnetic separation * microalgae Subject RIV: EI - Biotechnology ; Bionics Impact factor: 6.542, year: 2016

Cell disruption for microalgae biorefineries.

Science.gov (United States)

Günerken, E; D'Hondt, E; Eppink, M H M; Garcia-Gonzalez, L; Elst, K; Wijffels, R H

2015-01-01

Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave treatment, pulsed electric field treatment, non-mechanical cell disruption and some emerging technologies. Copyright © 2015 Elsevier Inc. All rights reserved.

KINERJA ENZIM GANDA PADA PRETREATMENT MIKROALGA UNTUK PRODUKSI BIOETANOL

Directory of Open Access Journals (Sweden)

Padil

2016-12-01

Full Text Available The use of biomass of microalgae as a feedstock to produce bioethanol is very promising, it is caused by a large amount of carbohydrates contained in microalgae physiology cell. The main obstacle of enzymatic hydrolysis in order to produce bioethanol is the bound starch granules in a rigid cell wall. Therefore, pre-treatment steps needed to remove and convert complex carbohydrates into simple sugars before the fermentation process. Tetraselmis Chuii microalgae species are green microalgae (Chlorophyta in which the cell wall containing cellulose and hemicellulose as the main constituent, therefore, this study observe the effect of the use of cellulase enzymes and xylanase as a strategy to open up the cell walls of microalgae. Another investigated parameter is the enzyme concentration, temperature, pH, and methods of use of enzymes. The results showed that the highest yield of glucose obtained was 31.912% (w / w and is achieved under the conditions of a temperature of 45oC, pH of 4.5, the amount of biomass of microalgae as 5 g/L, the concentration of cellulase enzymes and xilanase 30% (w / w at 40 minute at mechanism using cellulase and xylanase enzymes simultaneously.

Observations on the symbiosis between Colus gracilis (Da Costa, 1778) (Mollusca: Gastropoda) and Hormathia digitata (O.F. Müller, 1776) (Cnidaria: Actiniaria)

NARCIS (Netherlands)

Ates, R.M.L.

1998-01-01

Aquarium observations of the behaviour of the actinian Hormathia digitata when mounting live specimens of the gastropod Colus gracilis are fully described for the first time. C. gracilis actively initiates an association with H. digitata by approaching and remaining stationary near the actinian.

Biologically Active Metabolites Synthesized by Microalgae

Directory of Open Access Journals (Sweden)

Michele Greque de Morais

2015-01-01

Full Text Available Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences.

Physicochemical analysis of cellulose from microalgae ...

African Journals Online (AJOL)

African Journal of Biotechnology ... Nannochloropsis gaditana is a microalgae belonging to the class of Eustigmatophyceae. This particular microalga is the most studied species. For its richness in lipids, it is used for the biodiesel production.

Surgical repair of rectovaginal fistula using gracilis muscular flap. A case report

Energy Technology Data Exchange (ETDEWEB)

Inoue, Yasuhiro; Ooi, Masataka; Takeuchi, Kenji; Honzumi, Makoto [Nabari City Hospital, Mie (Japan); Fukunishi, Shigeji

1999-07-01

A 78 year-old female suffered from vaginal discharge of flatus and stool for 20 years after the radiation therapy for cervical cancer. Digital and endoscopic examination of the rectum and the vagina disclosed a large, short rectovaginal fistula at the level of the cervix. Since laparotomy and low anterior resection of the rectum were impossible, a perineal approach was adopted. After perineal skin incision, the fistula was resected and the defects of the rectum and the vagina were closed. Gracilis muscular flap was anchored between the two closures. Though the closure of the rectal side was torn, her postoperative course was uneventful. Endoscopic examination 24 days after the operation confirmed healing of the dehiscence. The results verified the usefulness of the perineal approach using the gracilis muscular flap as an alternative method to low anterior resection for troublesome radiation induced rectovaginal fistula. (author)

Surgical repair of rectovaginal fistula using gracilis muscular flap. A case report

International Nuclear Information System (INIS)

Inoue, Yasuhiro; Ooi, Masataka; Takeuchi, Kenji; Honzumi, Makoto; Fukunishi, Shigeji

1999-01-01

A 78 year-old female suffered from vaginal discharge of flatus and stool for 20 years after the radiation therapy for cervical cancer. Digital and endoscopic examination of the rectum and the vagina disclosed a large, short rectovaginal fistula at the level of the cervix. Since laparotomy and low anterior resection of the rectum were impossible, a perineal approach was adopted. After perineal skin incision, the fistula was resected and the defects of the rectum and the vagina were closed. Gracilis muscular flap was anchored between the two closures. Though the closure of the rectal side was torn, her postoperative course was uneventful. Endoscopic examination 24 days after the operation confirmed healing of the dehiscence. The results verified the usefulness of the perineal approach using the gracilis muscular flap as an alternative method to low anterior resection for troublesome radiation induced rectovaginal fistula. (author)

A mathematical model of microalgae growth in cylindrical photobioreactor

Science.gov (United States)

Bakeri, Noorhadila Mohd; Jamaian, Siti Suhana

2017-08-01

Microalgae are unicellular organisms, which exist individually or in chains or groups but can be utilized in many applications. Researchers have done various efforts in order to increase the growth rate of microalgae. Microalgae have a potential as an effective tool for wastewater treatment, besides as a replacement for natural fuel such as coal and biodiesel. The growth of microalgae can be estimated by using Geider model, which this model is based on photosynthesis irradiance curve (PI-curve) and focused on flat panel photobioreactor. Therefore, in this study a mathematical model for microalgae growth in cylindrical photobioreactor is proposed based on the Geider model. The light irradiance is the crucial part that affects the growth rate of microalgae. The absorbed photon flux will be determined by calculating the average light irradiance in a cylindrical system illuminated by unidirectional parallel flux and considering the cylinder as a collection of differential parallelepipeds. Results from this study showed that the specific growth rate of microalgae increases until the constant level is achieved. Therefore, the proposed mathematical model can be used to estimate the rate of microalgae growth in cylindrical photobioreactor.

Cultivation of the microalga, Chlorella pyrenoidosa , in biogas ...

African Journals Online (AJOL)

Therefore, the microalga was introduced to be cultivated in the biogas wastewater, which could not only bioremediate the wastewater, but also produce plenty of the microalga biomass that could be used for the exploitation of fertilizers, feed additives and biofuels. This study showed that the microalga, C. pyrenoidosa could ...

Fuels from microalgae

Energy Technology Data Exchange (ETDEWEB)

1989-06-01

Many species of aquatic plants can provide a source of renewable energy. Some species of microalgae, in particular, produce lipids -- oils that can be extracted and converted to a diesel fuel substitute or to gasoline. Since 1979 the Aquatic Species Program element of the Biofuels Program, has supported fundamental and applied research to develop the technology for using this renewable energy resource. This document, produced by the Solar Technical Information Program, provides an overview of the DOE/SERI Aquatic Species Program element. Chapter 1 is an introduction to the program and to the microalgae. Chapter 2 is an overview of the general principles involved in making fuels from microalgae. It also outlines the technical challenges to producing economic, high-energy transportation fuels. Chapter 3 provides an overview of the Algal Production and Economic Model (APEM). This model was developed by researchers within the program to identify aspects of the process critical to performance with the greatest potential to reduce costs. The analysis using this model has helped direct research sponsored by the program. Finally, Chapter 4 provides an overview of the Aquatic Species Program and describes current research. 28 refs., 17 figs.

Learning sustainability by developing a solar dryer for microalgae retrieval

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Benedita Malheiro

2016-01-01

Full Text Available Excessive fossil fuel consumption is driving the search for alternative energy production solutions and, in particular, for sustainable sources of energy such as microalgae, from which biodiesel, among other useful compounds, can be obtained. After producing the microalgae, they must be harvested and dried. Existing drying solutions consume too much energy and are, therefore, expensive and unsustainable. The goal of this EPS@ISEP Spring 2013 project was to develop a solar microalgae dryer for the microalgae laboratory of ISEP. A multinational team of five students from distinct fields of study was responsible for designing and building the solar microalgae dryer prototype. The prototype includes a control system to ensure that the microalgae are not destroyed during the drying process. The solar microalgae dryer works as a distiller, extracting the excess water from the microalgae suspension. This paper details the design steps, the building technologies, the ethical and sustainable concerns and compares the prototype with existing solutions. The proposed sustainable microalgae drying process is competitive as far as energy usage is concerned. Finally, the project contributed to increase the team’s sustainable development awareness, active learning and motivation.

Harvesting and cell disruption of microalgae

NARCIS (Netherlands)

Lam, 't Gerard Pieter

2017-01-01

Microalgae are a potential feedstock for various products. At the moment, they are already used as feedstock for high-valuable products (e.g. aquaculture and pigments).

Microalgae pre-dominantly consist out of proteins, lipids and carbohydrates. This makes algae an interesting feedstock

Proximal hamstring reconstruction using semitendinosus and gracilis autograft: a novel technique.

Science.gov (United States)

Muellner, Thomas; Kumar, Sandeep; Singla, Amit

2017-01-01

The complete proximal hamstring avulsion is relatively uncommon injury and predominantly occurs in young athletes but causes significant functional impairment. In chronic cases, the muscle mass is so much retracted that primary repair is not possible. A surgical technique for reconstruction of chronic proximal hamstring avulsion using contralateral semitendinosus and gracilis autograft is described in this case report. V.

The accordion gracilis muscle flap: a new design for coverage of recurrent and complicated ischeal pressure sores.

Science.gov (United States)

El-Sabbagh, Ahmed H

2011-10-01

Management of patients with large or recurrent pressure ulcerations can be complicated by the lack of available local flap, whether already used or because adjacent lesions make such flap insufficient for complete coverage. In this article, the gracilis muscle was modified to cover large defects without help from its cutaneous territory. Twelve ischeal pressure sores were treated between August 2007 and 2009 with the modified gracilis muscle flap in a single-staged procedure. Five ulcers were recurrent and seven patients have associated pressure ulcers. All reconstructions were successful. Mean patient age was 35 years and nearly all patients had multiple significant comorbidities, including associated ulcers, diabetes and urethrocutaneous fistula. All flaps and donor sites healed uneventfully. There was one complication presented as cellulites at the donor site. Follow-up in some cases extend up to 1·5 years. No recurrence was observed. The accordion gracilis muscle flap is a handy, safe and fast flap for reconstruction of recurrent, difficult ischeal pressure sores. © 2011 The Author. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Microalgae production in a biofilm photobioreactor

NARCIS (Netherlands)

Blanken, Ward

2016-01-01

Microalgae can be used to produce high-value compounds, such as pigments or high value fatty acids, or as a feedstock for lower value products such as food and feed compounds, biochemicals, and biofuels. In order to produce these bulk products competitively, it is required to lower microalgae

Effects of the essential oil of Lippia gracilis Schauer on caulinary shoots of heliconia cultivated in vitro Efeito do óleo essencial de Lippia gracilis Schauer sobre ápices caulinares de heliconia cultivadas in vitro

Directory of Open Access Journals (Sweden)

C.C. Albuquerque

2012-01-01

Full Text Available The effects of thymol and carvacrol and the essential oil of Lippia gracilis on caulinary shoots of heliconia were evaluated. After disinfection, the shoots were inoculated into MS medium and subjected to the treatments with 420 µL L-1 of essential oil (EO of L. gracilis; 420 µL L-1 of thymol; 420 µL L-1 of carvacrol; 210 µL L-1 of thymol and 210 µL L-1 of carvacrol. The control treatment consisted of the MS medium without any phytoregulators. The main components of EO from L. gracilis are carvacrol, ρ-cimene, and thymol. Seven days after the initiation of the experiments, 36.3% of the control treatment shoots were necrotized, but 90% of the caulinary shoots exposed to EO, thymol, or carvacrol appeared necrotized. Transmission electron microscopy of the shoots revealed that the treatment with EO, thymol, or carvacrol caused the destruction of the plasma cell membranes, and the cell organelles and the nucleus were hardly evident. The EO and its main constituent were toxic to caulinary shoots of heliconia.O efeito do timol, carvacrol e óleo essencial de Lippia gracilis foi observado sobre ápices caulinares de heliconia. Após a desinfestação os ápices foram inoculados em meio MS com os tratamentos de 420 µL L-1 do óleo essencial (OE de L. gracilis; 420 µL L-1 de timol; 420 µL L-1 de carvacrol; 210 µg L-1 de timol e 210 µL L-1 de carvacrol. O tratamento controle consistiu de meio MS sem fitorreguladores. Os principais componentes do OE foram carvacrol, ρ-cimeno e timol. Sete dias após o início do experimento 36,3% dos ápices submetidos ao tratamento controle e 90% dos ápices caulinares expostos ao EO, timol ou carvacrol necrosaram. A microscopia eletrônica de transmissão dos ápices caulinares revelou que os tratamentos com OE, timol e carvacrol provocaram desestruturação da membrana plasmática das células. As organelas e o núcleo não estavam evidentes. O OE e seus principais constituintes foram tóxico para os �

Microalgae as embedded environmental monitors

International Nuclear Information System (INIS)

Ogburn, Zachary L.; Vogt, Frank

2017-01-01

In marine ecosystems, microalgae are an important component as they transform large quantities of inorganic compounds into biomass and thereby impact environmental chemistry. Of particular relevance is phytoplankton's sequestration of atmospheric CO 2 , a greenhouse gas, and nitrate, one cause of harmful algae blooms. On the other hand, microalgae sensitively respond to changes in their chemical environment, which initiates an adaptation of their chemical composition. Analytical methodologies were developed in this study that utilize microalgae's adaptation as a novel approach for in-situ environmental monitoring. Longterm applications of these novel methods are investigations of environmental impacts on phytoplankton's sequestration performance and their nutritional value to higher organisms feeding on them. In order to analyze the chemical composition of live microalgae cells (Nannochloropsis oculata), FTIR-ATR spectroscopy has been employed. From time series of IR spectra, the formation of bio-sediment can be monitored and it has been shown that the nutrient availability has a small but observable impact. Since this bio-sediment formation is governed by several biological parameters of the cells such as growth rate, size, buoyancy, number of cells, etc., this enables studies of chemical environment's impact on biomass formation and the cells' physical parameters. Moreover, the spectroscopic signature of these microalgae has been determined from cultures grown under 25 different CO 2 and NO 3 − mixtures (200 ppm-600 ppm CO 2 , 0.35 mM-0.75 mM NO 3 − ). A novel, nonlinear modeling methodology coined ‘Predictor Surfaces’ is being presented by means of which the nonlinear responses of the cells to their chemical environment could reliably be described. This approach has been utilized to measure the CO 2 concentration in the atmosphere over the phytoplankton culture as well as the nitrate concentration dissolved in their growing

An Overview of Biocement Production from Microalgae

Directory of Open Access Journals (Sweden)

Dessy Ariyanti

2011-12-01

Full Text Available The invention of microorganism’s involvement in carbonate precipitation, has lead the exploration of this process in the field of construction engineering. Biocement is a product innovation from developing bioprocess technology called biocementation. Biocement refers to CaCO3 deposit that formed due to microorganism activity in the system rich of calcium ion. The primary role of microorganism in carbonate precipitation is mainly due to their ability to create an alkaline environment (high pH and DIC increase through their various physiological activities. Three main groups of microorganism that can induce the carbonate precipitation: (i photosynthetic microorganism such as cyanobacteria and microalgae; (ii sulphate reducing bacteria; and (iii some species of microorganism involved in nitrogen cycle. Microalgae are photosynthetic microorganism and utilize urea using urease or urea amidolyase enzyme, based on that it is possible to use microalgae as media to produce biocement through biocementation. This paper overviews biocement in general, biocementation, type of microorganism and their pathways in inducing carbonate precipitation and the prospect of microalgae to be used in biocement production.  Keywords— Biocement, Biocementation, Microalgae, CaCO3 precipitation

Heavy metal sorption by microalgae

International Nuclear Information System (INIS)

Sandau, E.; Sandau, P.; Pulz, O.

1996-01-01

Viable microalgae are known to be able to accumulate heavy metals (bioaccumulation). Against a background of the increasing environmental risks caused by heavy metals, the microalgae Chlorella vulgaris and Spirulina platensis and their potential for the biological removal of heavy metals from aqueous solutions were taken as an example for investigation. Small-scale cultivation tests (50 l) with Cd-resistant cells of Chlorella vulgaris have shown that approx. 40% of the added 10 mg Cd/l was removed from the solution within seven days. At this heavy metal concentration sensitive cells died. Non-viable microalgae are able to eliminate heavy metal ions in a short time by biosorption in uncomplicated systems, without any toxicity problems. Compared with original biomasses, the sorption capacity of microalgal by-products changes only insignificantly. Their low price makes them economical. (orig.)

Evaluación de la bioacumulación de cobre en Euglena gracilis mediante la técnica de fluorescencia de rayos X

Directory of Open Access Journals (Sweden)

David Cervantes-Garcia

2014-07-01

Full Text Available En esta investigación se evaluó el efecto de la exposición de cobre en la capacidad de bioacumulación de metal en células de Euglena gracilis. La acumulación de metal medida con la técnica de fluorescencia de rayos X (XRF mostró que la acumulación de Cu+2 en E. gracilis fue dosis dependiente y se incrementó significativamente en las células tratadas con 0.4 y 0.8 mM de Cu+2 con respecto al control. No se descarta la presencia de una estrategia de acumulación en E. gracilis que podría involucrar la participación de una serie de múltiples procesos, como producción de vacuolas. Futuros estudios al respecto deberán orientarse a evaluar la capacidad de bioacumulación de E. gracilis para su aplicación en programas de biorremediación de sistemas acuáticos.

Microalgae as embedded environmental monitors

Energy Technology Data Exchange (ETDEWEB)

Ogburn, Zachary L.; Vogt, Frank, E-mail: fvogt@utk.edu

2017-02-15

In marine ecosystems, microalgae are an important component as they transform large quantities of inorganic compounds into biomass and thereby impact environmental chemistry. Of particular relevance is phytoplankton's sequestration of atmospheric CO{sub 2}, a greenhouse gas, and nitrate, one cause of harmful algae blooms. On the other hand, microalgae sensitively respond to changes in their chemical environment, which initiates an adaptation of their chemical composition. Analytical methodologies were developed in this study that utilize microalgae's adaptation as a novel approach for in-situ environmental monitoring. Longterm applications of these novel methods are investigations of environmental impacts on phytoplankton's sequestration performance and their nutritional value to higher organisms feeding on them. In order to analyze the chemical composition of live microalgae cells (Nannochloropsis oculata), FTIR-ATR spectroscopy has been employed. From time series of IR spectra, the formation of bio-sediment can be monitored and it has been shown that the nutrient availability has a small but observable impact. Since this bio-sediment formation is governed by several biological parameters of the cells such as growth rate, size, buoyancy, number of cells, etc., this enables studies of chemical environment's impact on biomass formation and the cells' physical parameters. Moreover, the spectroscopic signature of these microalgae has been determined from cultures grown under 25 different CO{sub 2} and NO{sub 3}{sup −} mixtures (200 ppm-600 ppm CO{sub 2}, 0.35 mM-0.75 mM NO{sub 3}{sup −}). A novel, nonlinear modeling methodology coined ‘Predictor Surfaces’ is being presented by means of which the nonlinear responses of the cells to their chemical environment could reliably be described. This approach has been utilized to measure the CO{sub 2} concentration in the atmosphere over the phytoplankton culture as well as the nitrate

Distinctive Architecture of the Chloroplast Genome in the Chlorodendrophycean Green Algae Scherffelia dubia and Tetraselmis sp. CCMP 881.

Science.gov (United States)

Turmel, Monique; de Cambiaire, Jean-Charles; Otis, Christian; Lemieux, Claude

2016-01-01

The Chlorodendrophyceae is a small class of green algae belonging to the core Chlorophyta, an assemblage that also comprises the Pedinophyceae, Trebouxiophyceae, Ulvophyceae and Chlorophyceae. Here we describe for the first time the chloroplast genomes of chlorodendrophycean algae (Scherffelia dubia, 137,161 bp; Tetraselmis sp. CCMP 881, 100,264 bp). Characterized by a very small single-copy (SSC) region devoid of any gene and an unusually large inverted repeat (IR), the quadripartite structures of the Scherffelia and Tetraselmis genomes are unique among all core chlorophytes examined thus far. The lack of genes in the SSC region is offset by the rich and atypical gene complement of the IR, which includes genes from the SSC and large single-copy regions of prasinophyte and streptophyte chloroplast genomes having retained an ancestral quadripartite structure. Remarkably, seven of the atypical IR-encoded genes have also been observed in the IRs of pedinophycean and trebouxiophycean chloroplast genomes, suggesting that they were already present in the IR of the common ancestor of all core chlorophytes. Considering that the relationships among the main lineages of the core Chlorophyta are still unresolved, we evaluated the impact of including the Chlorodendrophyceae in chloroplast phylogenomic analyses. The trees we inferred using data sets of 79 and 108 genes from 71 chlorophytes indicate that the Chlorodendrophyceae is a deep-diverging lineage of the core Chlorophyta, although the placement of this class relative to the Pedinophyceae remains ambiguous. Interestingly, some of our phylogenomic trees together with our comparative analysis of gene order data support the monophyly of the Trebouxiophyceae, thus offering further evidence that the previously observed affiliation between the Chlorellales and Pedinophyceae is the result of systematic errors in phylogenetic reconstruction.

Mixotrophic cultivation of microalgae for biodiesel production: status and prospects.

Science.gov (United States)

Wang, Jinghan; Yang, Haizhen; Wang, Feng

2014-04-01

Biodiesel from microalgae provides a promising alternative for biofuel production. Microalgae can be produced under three major cultivation modes, namely photoautotrophic cultivation, heterotrophic cultivation, and mixotrophic cultivation. Potentials and practices of biodiesel production from microalgae have been demonstrated mostly focusing on photoautotrophic cultivation; mixotrophic cultivation of microalgae for biodiesel production has rarely been reviewed. This paper summarizes the mechanisms and virtues of mixotrophic microalgae cultivation through comparison with other major cultivation modes. Influencing factors of microalgal biodiesel production under mixotrophic cultivation are presented, development of combining microalgal biodiesel production with wastewater treatment is especially reviewed, and bottlenecks and strategies for future commercial production are also identified.

Use of alternative media and different types of recipients in a laboratory culture of Ankistrodesmus gracilis (Reinsch Korshikov (Chlorophyceae - doi: 10.4025/actascibiolsci.v33i3.8046 Use of alternative media and different types of recipients in a laboratory culture of Ankistrodesmus gracilis (Reinsch Korshikov (Chlorophyceae - doi: 10.4025/actascibiolsci.v33i3.8046

Directory of Open Access Journals (Sweden)

Flávia de Almeida Berchielli

2011-07-01

Full Text Available A laboratory culture of Ankistrodesmus gracilis algae was evaluated by studying the biology of the species and its chemical composition in a traditional medium (CHU12 and in two alternative culture media, NPK (20-5-20 and macrophyte (Eichhornia crassipes + NPK, in three different types of recipients (fiberglass, carboy and plastic bag. First peak in the growth curve of Ankistrodesmus gracilis occurred on the ninth day in macrophyte + NPK medium (74.16 x 105 cells mL-1 in a fiberglass recipient. However, highest density (p 12 (122.87 x 105 cells mL-1 in a plastic bag on the twelfth day. Cell density was over 70 x 105 cells mL-1 starting on the twelfth day. Growth rate of A. gracilis was similar (p > 0.05 in culture media in the three recipients. Protein and fiber were similar (p > 0.05 in the treatments, but lipids were higher (p -1 in NPK (p A. gracilis cultured in three types of recipients. Costs are low, occupying less space when cultured in plastic bags and in the laboratory.A laboratory culture of Ankistrodesmus gracilis algae was evaluated by studying the biology of the species and its chemical composition in a traditional medium (CHU12 and in two alternative culture media, NPK (20-5-20 and macrophyte (Eichhornia crassipes + NPK, in three different types of recipients (fiberglass, carboy and plastic bag. First peak in the growth curve of Ankistrodesmus gracilis occurred on the ninth day in macrophyte + NPK medium (74.16 x 105 cells mL-1 in a fiberglass recipient. However, highest density (p 12 (122.87 x 105 cells mL-1 in a plastic bag on the twelfth day. Cell density was over 70 x 105 cells mL-1 starting on the twelfth day. Growth rate of A. gracilis was similar (p > 0.05 in culture media in the three recipients. Protein and fiber were similar (p > 0.05 in the treatments, but lipids were higher (p -1 in NPK (p A. gracilis cultured in three types of recipients. Costs are low, occupying less space when cultured in plastic bags and in the

Flashing light in microalgae biotechnology.

Science.gov (United States)

Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

2016-03-01

Flashing light can enhance photosynthesis and improve the quality and quantity of microalgal biomass, as it can increase the products of interest by magnitudes. Therefore, the integration of flashing light effect into microalgal cultivation systems should be considered. However, microalgae require a balanced mix of the light/dark cycle for higher growth rates, and respond to light intensity differently according to the pigments acquired or lost during the growth. This review highlights recently published results on flashing light effect on microalgae and its applications in biotechnology, as well as the recently developed bioreactors designed to fulfill this effect. It also discusses how this knowledge can be applied in selecting the optimal light frequencies and intensities with specific technical properties for increasing biomass production and/or the yield of the chemicals of interest by microalgae belonging to different genera. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microalgal CO2 sequestering – Modeling microalgae production costs

International Nuclear Information System (INIS)

Bilanovic, Dragoljub; Holland, Mark; Armon, Robert

2012-01-01

Highlights: ► Microalgae production costs were modeled as a function of specific expenses. ► The effects of uncontrollable expenses/factors were incorporated into the model. ► Modeled microalgae production costs were in the range $102–1503 t −1 ha −1 y −1 . - Abstract: Microalgae CO 2 sequestering facilities might become an industrial reality if microalgae biomass could be produced at cost below $500.00 t −1 . We develop a model for estimation of total production costs of microalgae as a function of known production-specific expenses, and incorporate into the model the effects of uncontrollable factors which affect known production-specific expenses. Random fluctuations were intentionally incorporated into the model, consequently into generated cost/technology scenarios, because each and every logically interconnected equipment/operation that is used in design/construction/operation/maintenance of a production process is inevitably subject to random cost/price fluctuations which can neither be eliminated nor a priori controlled. A total of 152 costs/technology scenarios were evaluated to find 44 scenarios in which predicted total production costs of microalgae (PTPCM) was in the range $200–500 t −1 ha −1 y −1 . An additional 24 scenarios were found with PTCPM in the range of $102–200 t −1 ha −1 y −1 . These findings suggest that microalgae CO 2 sequestering and the production of commercial compounds from microalgal biomass can be economically viable venture even today when microalgae production technology is still far from its optimum.

Use of secondary sewage water as a culture medium for Chaetoceros gracilis and Thalassiosira Sp (Chrysophyceae in laboratory conditions

Directory of Open Access Journals (Sweden)

Rauquírio André Albuquerque Marinho da Costa

1999-01-01

Full Text Available Experiments were carried out in order to test the efficiency of additions of secondary sewage as a culture medium for Chaetoceros gracilis and Thalassiosira sp (Chrysophyceae under laboratory conditions. These algae were cultivated in sea water with concentrations of 10%, 20%, 30% and 40% of wastewater. The results were compared with those obtained by the nutritive medium f2 of Guillard (1975. The best results in terms of cellular densities were observed at 40% additions. There were significant differences (significance levels of 5% between the nutritive medium f2 and the 40% additions for both the species. Maximum cellular densities observed for all additions tested were, 4,125.00 x 10³ cells/ml for Chaetoceros gracilis on the ninth day and 834.00 x 10³ cells/ml for Thalassiosira sp on the fifth day. Biomass was higher in the nutritive medium f2 than in the other treatments, reaching average values of 2,363μg/ml for Chaetoceros gracilis. At all experimental units, the best results were registered at 40% addition for Chaetoceros gracilis, where average values of 0.768μg/ml were observed on the fifth day, and at 30% additions for Thalassiosira sp where 0.883μg/ml were observed on the thirteenth day. It was concluded that secondary sewage could be used as a culture medium for the species tested here, after large scale tests.

Sequence Evidence for the Presence of Two Tetrapyrrole Pathways in Euglena gracilis

Czech Academy of Sciences Publication Activity Database

Kořený, Luděk; Oborník, Miroslav

2011-01-01

Roč. 3, - (2011), 359-364 ISSN 1759-6653 R&D Projects: GA ČR GA206/08/1423; GA ČR GD206/09/H026 Institutional research plan: CEZ:AV0Z60220518 Keywords : tetrapyrrole synthesis * heme pathway * Euglena gracilis * secondary endosymbiosis * evolution * plastid Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.618, year: 2011

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.

Modeling and Control of Algae Harvesting, Dewatering and Drying (HDD) Systems

Science.gov (United States)

2012-05-01

concentration to 5% water based on latent heat of vaporization Algae Botryococcus braunii Chlorella vulgaris Euglena gracilis Nannochlorops is...microalga Chlorella protothecoides by heterotrophic growth in fermenters. J Biotechnol 126:499–507, 2006 [9] Acièn Fernández F-G, Garcìa Camacho F

Induction of anthocyanin formation and of enzymes related to its biosynthesis by UV light in cell cultures of Haplopappus gracilis

International Nuclear Information System (INIS)

Wellmann, E.; Hrazdina, G.; Grisebach, H.

1976-01-01

Only UV light below 345 nm stimulates anthocyanin formation in dark grown cell suspension cultures of Haplopappus gracilis. A linear relationship between UV dose and flavonoid accumulation, as found previously with parsley cell cultures was not observed with the H.gracilis cells. Only continuous irradiation with high doses of UV was effective. Drastic increases in the activities of the enzymes phenylalanine ammonia-lyase, chalcone isomerase and flavanone synthase were observed under continuous UV light. The increase in enzyme activities paralleled anthocyanin formation. (author)

Microalgae - A promising tool for heavy metal remediation.

Science.gov (United States)

Suresh Kumar, K; Dahms, Hans-Uwe; Won, Eun-Ji; Lee, Jae-Seong; Shin, Kyung-Hoon

2015-03-01

Biotechnology of microalgae has gained popularity due to the growing need for novel environmental technologies and the development of innovative mass-production. Inexpensive growth requirements (solar light and CO2), and, the advantage of being utilized simultaneously for multiple technologies (e.g. carbon mitigation, biofuel production, and bioremediation) make microalgae suitable candidates for several ecofriendly technologies. Microalgae have developed an extensive spectrum of mechanisms (extracellular and intracellular) to cope with heavy metal toxicity. Their wide-spread occurrence along with their ability to grow and concentrate heavy metals, ascertains their suitability in practical applications of waste-water bioremediation. Heavy metal uptake by microalgae is affirmed to be superior to the prevalent physicochemical processes employed in the removal of toxic heavy metals. In order to evaluate their potential and to fill in the loopholes, it is essential to carry out a critical assessment of the existing microalgal technologies, and realize the need for development of commercially viable technologies involving strategic multidisciplinary approaches. This review summarizes several areas of heavy metal remediation from a microalgal perspective and provides an overview of various practical avenues of this technology. It particularly details heavy metals and microalgae which have been extensively studied, and provides a schematic representation of the mechanisms of heavy metal remediation in microalgae. Copyright © 2014 Elsevier Inc. All rights reserved.

Microalgae bulk growth model with application to industrial scale systems

NARCIS (Netherlands)

Quinn, J.; Winter, de L.; Bradley, T.

2011-01-01

The scalability of microalgae growth systems is a primary research topic in anticipation of the commercialization of microalgae-based biofuels. To date, there is little published data on the productivity of microalgae in growth systems that are scalable to commercially viable footprints. To inform

Microalgae biorefineries: The Brazilian scenario in perspective.

Science.gov (United States)

Brasil, B S A F; Silva, F C P; Siqueira, F G

2017-10-25

Biorefineries have the potential to meet a significant part of the growing demand for energy, fuels, chemicals and materials worldwide. Indeed, the bio-based industry is expected to play a major role in energy security and climate change mitigation during the 21th century. Despite this, there are challenges related to resource consumption, processing optimization and waste minimization that still need to be overcome. In this context, microalgae appear as a promising non-edible feedstock with advantages over traditional land crops, such as high productivity, continuous harvesting throughout the year and minimal problems regarding land use. Importantly, both cultivation and microalgae processing can take place at the same site, which increases the possibilities for process integration and a reduction in logistic costs at biorefinery facilities. This review describes the actual scenario for microalgae biorefineries integration to the biofuels and petrochemical industries in Brazil, while highlighting the major challenges and recent advances in microalgae large-scale production. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling and visual simulation of Microalgae photobioreactor

Science.gov (United States)

Zhao, Ming; Hou, Dapeng; Hu, Dawei

Microalgae is a kind of nutritious and high photosynthetic efficiency autotrophic plant, which is widely distributed in the land and the sea. It can be extensively used in medicine, food, aerospace, biotechnology, environmental protection and other fields. Photobioreactor which is important equipment is mainly used to cultivate massive and high-density microalgae. In this paper, based on the mathematical model of microalgae which grew under different light intensity, three-dimensional visualization model was built and implemented in 3ds max, Virtools and some other three dimensional software. Microalgae is photosynthetic organism, it can efficiently produce oxygen and absorb carbon dioxide. The goal of the visual simulation is to display its change and impacting on oxygen and carbon dioxide intuitively. In this paper, different temperatures and light intensities were selected to control the photobioreactor, and dynamic change of microalgal biomass, Oxygen and carbon dioxide was observed with the aim of providing visualization support for microalgal and photobioreactor research.

Nanosilver microalgae biosynthesis: cell appearance based on SEM and EDX methods

Science.gov (United States)

Pancasakti Kusumaningrum, Hermin; Zainuri, Muhammad; Marhaendrajaya, Indras; Subagio, Agus

2018-05-01

Microbial contamination has caused public health problems in the world population. This problem has spurred the development of methods to overcome and prevent microbial invasion. The extensive use of antibiotics has facilitated the continued emergence and spread of resistant organisms. Synthesized of silver nanoparticle (AgNPs) on microalgae Chlorella pyrenoidosa offer environmentally safe antimicrobial agent. The present study is focused on the biosynthesis of AgNPs using microalgae C. pyrenoidosa. The research methods was conducted by insertion of nanosilver particle into microalgae cells with and without agitation to speed up the process of formation nanosilver microalgae. The formation of microalgae SNP was analyzes by UV-Vis spectrophotometer, Scanning Electron Micrograph (SEM) and Energy-dispersive X-ray spectroscopy (EDX) methods. The research result showed that nanosilver microalgae biosynthesis using the agitation treatment was exhibited better performance in particle insertion and cell stability, comparing with no agitation treatment. However, synthesis of nanosilver microalgae tend to reduce the cell size.

Lipid extraction from microalgae using a single ionic liquid

Science.gov (United States)

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

2013-05-28

A one-step process for the lysis of microalgae cell walls and separation of the cellular lipids for use in biofuel production by utilizing a hydrophilic ionic liquid, 1-butyl-3-methylimidazolium. The hydrophilic ionic liquid both lyses the microalgae cell walls and forms two immiscible layers, one of which consists of the lipid contents of the lysed cells. After mixture of the hydrophilic ionic liquid with a suspension of microalgae cells, gravity causes a hydrophobic lipid phase to move to a top phase where it is removed from the mixture and purified. The hydrophilic ionic liquid is recycled to lyse new microalgae suspensions.

Phaeobacter gallaeciensis Reduces Vibrio anguillarum in Cultures of Microalgae and Rotifers, and Prevents Vibriosis in Cod Larvae

Science.gov (United States)

D’Alvise, Paul W.; Lillebø, Siril; Prol-Garcia, Maria J.; Wergeland, Heidrun I.; Nielsen, Kristian F.; Bergh, Øivind; Gram, Lone

2012-01-01

Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 107 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA) did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua) to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect. PMID:22928051

Phaeobacter gallaeciensis reduces Vibrio anguillarum in cultures of microalgae and rotifers, and prevents vibriosis in cod larvae.

Directory of Open Access Journals (Sweden)

Paul W D'Alvise

Full Text Available Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect.

Wet torrefaction of microalga Chlorella vulgaris ESP-31 with microwave-assisted heating

International Nuclear Information System (INIS)

Bach, Quang-Vu; Chen, Wei-Hsin; Lin, Shih-Cheng; Sheen, Herng-Kuang; Chang, Jo-Shu

2017-01-01

Highlights: • A microwave-assisted heating system is used for wet torrefaction (WT) of microalga. • Microalga Chlorella vulgaris ESP-31 is adopted as the feedstock. • The ash content in the microalga is reduced after WT. • The calorific value of the microalga can be intensified up to 21% after WT. • At least 61.5% of energy in the biomass is retained after WT. - Abstract: Microalgae are a prime source of third generation biofuels. Many thermochemical processes can be applied to convert them into fuels and other valuable products. However, some types of microalgae are characterized by very high moisture and ash contents, thereby causing several problems in further conversion processes. This study presents wet torrefaction (WT) as a promising pretreatment method to overcome the aforementioned drawbacks coupled with microalgal biomass. For this purpose, a microwave-assisted heating system was used for WT of microalga Chlorella vulgaris ESP-31 at different reaction temperatures (160, 170, and 180 °C) and durations (5, 10, and 30 min). The results show several improvements in the fuel properties of the microalga after WT such as increased calorific value and hydrophobicity as well as reduced ash content. A correlation in terms of elemental analysis can be adopted to predict the higher heating value of the torrefied microalga. The structure analysis by Fourier transform infrared (FT-IR) spectroscopy reveals that the carbohydrate content in the torrefied microalgae is lowered, whereas their protein and lipid contents are increased if the WT extent is not severe. However, the protein and lipid contents are reduced significantly at more severe WT conditions. The thermogravimetric analysis shows that the torrefied microalgae have lower ignition temperatures but higher burnout temperatures than the raw microalga, revealing significant impact of WT on the combustion reactivity of the microalga. Overall, the calorific value of the microalga can be intensified up to

Redescription of the Indo-West Pacific cardinalfishes (Perciformes: Apogonidae) Rhabdamia spilota Allen Kuiter 1994 and R. gracilis (Bleeker 1856).

Science.gov (United States)

Yoshida, Tomohiro; Motomura, Hiroyuki

2018-01-31

Rhabdamia spilota Allen Kuiter 1994 (Apogonidae), a poorly known cardinalfish previously known only from the Philippines, Indonesia and the Red Sea, is redescribed on the basis of 70 specimens (20.9-61.2 mm standard length) (including types), from the Indo-West Pacific (Red Sea, Andaman Sea, Japan, South China Sea, the Philippines, Indonesia, New Caledonia, and Australia). Because most reports of the similar species R. gracilis (Bleeker 1856), following its original description, were based on misidentifications, R. gracilis is also redescribed (based on 98 Indo-West Pacific specimens from Seychelles, Maldives, Andaman Sea, Japan, Malaysia, Indonesia, New Caledonia, and Australia, 27.9-59.3 mm standard length); a lectotype is designated for it. Rhabdamia spilota differs from R. gracilis in having 27-33 (mode 30-31) developed gill rakers [vs. 22-27 (mode 24) in the latter], 27-33 (30) gill rakers including rudiments [vs. 23-27 (24-25)], a black stripe from the jaw tips to the anterior margin of the orbit (vs. black pigments only at snout and tip of lower jaw), 3-6 reddish brown to blackish blotches on the opercle and anterior of body (vs. blotches absent), and indistinct black pigment restricted to caudal fin outer margins (vs. pigment scattered over entire fin). Rhabdamia gracilis exhibits sexual dichromatism, female specimens larger than 41.3 mm SL having one or two black stripes on the lateral surface of the body; the stripes are absent in males and smaller females. No evidence of sexual dichromatism was found in R. spilota.

Microalgae for biofuels production and environmental applications ...

African Journals Online (AJOL)

This review presents the current classification of biofuels, with special focus on microalgae and their applicability for the production of biodiesel. The paper considered issues related with the processing and culturing of microalgae, for not only those that are involved in biofuel production, but as well as the possibility of their ...

Pilot-scale continuous recycling of growth medium for the mass culture of a halotolerant Tetraselmis sp. in raceway ponds under increasing salinity: a novel protocol for commercial microalgal biomass production.

Science.gov (United States)

Fon Sing, S; Isdepsky, A; Borowitzka, M A; Lewis, D M

2014-06-01

The opportunity to recycle microalgal culture medium for further cultivation is often hampered by salinity increases from evaporation and fouling by dissolved and particulate matter. In this study, the impact of culture re-use after electro-flocculation of seawater-based medium on growth and biomass productivity of the halotolerant green algal strain Tetraselmis sp., MUR 233, was investigated in pilot-scale open raceway ponds over 5months. Despite a salinity increase from 5.5% to 12% (w/v) NaCl, Tetraselmis MUR 233 grown on naturally DOC-enriched recycled medium produced 48-160% more ash free dry weight (AFDW) biomass daily per unit pond area than when grown on non-recycled medium. A peak productivity of 37.5±3.1gAFDWm(-2)d(-1) was reached in the recycled medium upon transition from ∼14% to ∼7% NaCl. The combination of high biomass-yielding mixotrophic growth under high salinity has been proven to be a successful sustainable cultivation strategy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Uptake of uranium from sea water by microalgae

International Nuclear Information System (INIS)

Sakaguchi, Takashi; Horikoshi, Takao; Nakajima, Akira

1978-01-01

The uptake of uranium from aqueous systems especially from sea water by various microalgae was investigated. The freshwater microalgae, Chlorella regularis, Scenedesmus bijuga, Scenedesmus chloreloides, Scenedesmus obliquus, Chlamydomonas angulosa, Chlamydomonas reinhardtii, accumulated relatively large amounts of uranium from the solution containing uranium only. The concentration factors of the above mentioned algae were: Chlorella regularis 3930, Chlamydomonas 2330 - 3400, Scenedesmus 803 - 1920. The uptake of uranium from sea water by Chlorella regularis was inhibited markedly by the co-existence of carbonate ions. Chlorella cells could take up a great quantity of uranium from decarbonated sea water. The uptake of uranium was affected by the pH of sea water, and the amount of uranium absorbed was maximum at pH 5. The experiment was carried out to screen marine microalgae which have the ability to accumulate a large amount of uranium from sea water. The uptake of uranium from sea water by marine microalgae of different species turned out to be in the following decreasing order: Synechococcus > Chlamydomonas >> Chlorella > Dunaliella > Platymonas > Calothrix > Porphyridium. The amount of uranium absorbed differed markedly with different species of marine microalgae. (author)

Influence of Microalgae onto submerged surfaces on Fouling

Science.gov (United States)

Kong, M.; Eom, C.; Yoon, B.; Yoon, H.; Kim, B.; Chung, K.

2012-12-01

Lots of algae together with organic matter deposited on the submerged surface can be easily observed occurring in the shallower water along the coast. This is mainly because only those organisms with the ability to adapt to the new situations created by man can firmly adhere enough to avoid being washed off. Chemical and microbiological characteristics of the fouling microalgae developed on various surfaces in contact with the seawater were made. The microbial compositions of the microalgae formed on the submerged surfaces were tested for. The quantities of the diverse microalgae in the samples developed on the prohibiting submerged surface were larger when there was no concern about materials for special selection for fouling. To confirm formation of microalgae on adsorbents was done SEM-EDS (Scanning Electron Microscope-Spectrometer) analysis. Microbial identified using optical microscope. In addition to, we quantified attaching microalgae as pass time. Experiment results, ten species which are Nitzshhia sp., Eucampia sp., Coscinodiscus sp., Licmophora sp., Rhizosolenia sp., Cylindrotheca sp., Striateela sp., Thalassionema sp., Guinardia sp., and Helicostomella sp. discovered to reservoir formed biofouling. They showed the important role microbial activity in fouling and corrosion of the surfaces in contact with the any seawater.

Microalgae as healthy ingredients for functional food: a review.

Science.gov (United States)

Matos, J; Cardoso, C; Bandarra, N M; Afonso, C

2017-08-01

Microalgae are very interesting and valuable natural sources of highly valuable bioactive compounds, such as vitamins, essential amino acids, polyunsaturated fatty acids, minerals, carotenoids, enzymes and fibre. Due to their potential, microalgae have become some of the most promising and innovative sources of new food and functional products. Moreover, microalgae can be used as functional ingredients to enhance the nutritional value of foods and, thus, to favourably affect human health by improving the well-being and quality of life, but also by curtailing disease and illness risks. This review provides an overview of the current knowledge of the health benefits associated with the consumption of microalgae, bioactive compounds, functional ingredients, and health foods.

Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

Science.gov (United States)

Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

2016-03-01

Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potential of microalgae in the bioremediation of water with chloride content.

Science.gov (United States)

Ramírez, M E; Vélez, Y H; Rendón, L; Alzate, E

2017-10-23

In this work it was carried out the bioremediation of water containing chlorides with native microalgae (MCA) provided by the Centre for study and research in biotechnology (CIBIOT) at Universidad Pontificia Bolivariana. Microalgae presented an adaptation to the water and so the conditions evaluated reaching a production of CO2 in mg L-1 of 53.0, 26.6, 56.0, 16.0 and 30.0 and chloride removal efficiencies of 16.37, 26.03, 40.04, 25.96 and 20.25% for microalgae1, microalgae2, microalgae3, microalgae4 and microalgae5 respectively. Water bioremediation process was carried out with content of chlorides in fed batch system with an initial concentration of chlorides of 20585 mg L-1 every 2 days. The Manipulated variables were: the flow of MCA3 (10% inoculum) for test one; NPK flow for test two, and flow of flow of MCA3+0.5 g L-1 NPK. Chloride removal efficiencies were 66.88%, 63.41% and 66.98% for test one, two and three respectively, for a total bioprocess time of 55 days.

Advances in Microalgae-Derived Phytosterols for Functional Food and Pharmaceutical Applications.

Science.gov (United States)

Luo, Xuan; Su, Peng; Zhang, Wei

2015-07-09

Microalgae contain a variety of bioactive lipids with potential applications in aquaculture feed, biofuel, food and pharmaceutical industries. While microalgae-derived polyunsaturated fatty acid (PUFA) and their roles in promoting human health have been extensively studied, other lipid types from this resource, such as phytosterols, have been poorly explored. Phytosterols have been used as additives in many food products such as spread, dairy products and salad dressing. This review focuses on the recent advances in microalgae-derived phytosterols with functional bioactivities and their potential applications in functional food and pharmaceutical industries. It highlights the importance of microalgae-derived lipids other than PUFA for the development of an advanced microalgae industry.

Microalgae as sustainable renewable energy feedstock for biofuel production.

Science.gov (United States)

Medipally, Srikanth Reddy; Yusoff, Fatimah Md; Banerjee, Sanjoy; Shariff, M

2015-01-01

The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae.

Science.gov (United States)

Wijffels, René H; Kruse, Olaf; Hellingwerf, Klaas J

2013-06-01

Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments. Cyanobacteria are promising host organisms for the production of small molecules that can be secreted such as ethanol, butanol, fatty acids and other organic acids. Eukaryotic microalgae are interesting for products for which cellular storage is important such as proteins, lipids, starch and alkanes. For the development of new and promising lines of production, strains of both cyanobacteria and eukaryotic microalgae have to be improved. Transformation systems have been much better developed in cyanobacteria. However, several products would be preferably produced with eukaryotic microalgae. In the case of cyanobacteria a synthetic-systems biology approach has a great potential to exploit cyanobacteria as cell factories. For eukaryotic microalgae transformation systems need to be further developed. A promising strategy is transformation of heterologous (prokaryotic and eukaryotic) genes in established eukaryotic hosts such as Chlamydomonas reinhardtii. Experimental outdoor pilots under containment for the production of genetically modified cyanobacteria and microalgae are in progress. For full scale production risks of release of genetically modified organisms need to be assessed. Copyright © 2013. Published by Elsevier Ltd.

Microalgae as Sustainable Renewable Energy Feedstock for Biofuel Production

Directory of Open Access Journals (Sweden)

Srikanth Reddy Medipally

2015-01-01

Full Text Available The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

Microalgae as Sustainable Renewable Energy Feedstock for Biofuel Production

Science.gov (United States)

Yusoff, Fatimah Md.; Shariff, M.

2015-01-01

The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties. PMID:25874216

Bioelectricity Production from Microalgae-Microbial Fuel Cell Technology (MMFC

Directory of Open Access Journals (Sweden)

da Costa Carlito

2018-01-01

Full Text Available Microbial fuel cell is an ecological innovative technology producing bioelectricity by utilizing microbes activity. Substituent energy is produced by changing the chemical energy to electrical energy through the catalytic reaction of microorganism. The research aims to find out the potency of bioelectricity produced by microalgae microbial fuel cell technology by utilizing the combination of tapioca wastewater and microalgae cultivation. This research is conducted through the ingredients preparation stage – microalgae culture, wastewater characterization, membrane and graphite activation, and the providing of other supporting equipment. The next stage is the MMFC arrangement, while the last one is bioelectricity measurement. The result of optimal bioelectricity production on the comparison of electrode 2 : 2, the power density is 44,33 mW/m2 on day 6, meanwhile, on that of 1 : 1, 20,18 mW/m2 power density on day 1 is obtained. It shows that bioelectricity can be produced from the combination of tapioca wastewater and microalgae culture through the microalgae-microbial fuel cell (MMFC technology.This research is expected to be a reference for the next research particularly the one that observes the utilizing of microalgae as the part of new and renewable energy sources.

Fatty Acid Content of Indonesian Aquatic Microalgae

Directory of Open Access Journals (Sweden)

TRI PRARTONO

2010-12-01

Full Text Available High utilization of fossil fuel increases the level of carbon dioxide in the atmosphere and results in global warming phenomenon. These things establish the world's thought to look for the other alternative energy that can reduce the use of fossil fuel even to be replaced by the substitute. Recently, Indonesia has been doing the research of microalgae as a feedstock of an alternative biofuel. Fatty acid content that microalgae have is also high to produce biofuel. The steps used in this research is a 7 days cultivation, harvesting, extraction using hexane, and fatty acid identification using Gas Chromatography of microalgae species. Fatty acid component in some species such as Chlorella sp., Scenedesmus sp., Nannochloropsis sp., and Isochrysis sp. is between 0.21-29.5%; 0.11-25.16%; 0.30-42.32%; 2.06-37.63%, respectively, based on dry weight calculation. The high content of fatty acid in some species of microalgae showed the potential to be the feedstock of producing biofuel in overcoming the limited utilization from petroleum (fossil fuel presently.

Harvesting of freshwater microalgae biomass by Scenedesmus sp. as bioflocculant

Science.gov (United States)

Rinanti, A.; Purwadi, R.

2018-01-01

This study is particularly expected to provide information on the diversity of microalgae as the flocculant agent that gives the highest biomass yield. Bioflocculation was done by using one of the flocculating microalgae i.e. Scenedesmus obliquus to concentrate on non-flocculating microalgae Chlorella vulgaris. The freshwater microalgae S. obliquus tested it ability to harvest other non-flocculating microalgae, increased sedimentation rate in the flocculation process and increased biomass yield. The flocculation of biomass microalgae with chemical flocculant as comparison was done by adding alum (K2SO4·Al2 (SO4)3·24H2O). The addition of alum (K2SO4·Al2 (SO4)3·24H2O) as flocculant at pH 11 and S. obliquus sp. as bioflocculant caused significant alteration of nutrition of microalgae. Overall, the essential content produced by flocculation method with addition of alum or with bioflocculation (%, mg/100 mg dry weight) are lipid 31,64; 38,69, protein 30,79; 38.50%, and chlorophyll 0.6253; 0.8420). Harvesting with bioflocculation methods conducted at the end of the cultivation period increase the amount of biomass significantly and can accelerate the settling time of biomass. Harvesting microalgae cells by bioflocculation method becomes an economically competitive harvesting method compared to alum as a chemical flocculant because of the cheaper cost of flocculant, not toxic so it does not require further water treatment after harvesting due to the use of alum as chemical flocculants.

Use of alternative media and different types of recipients in a laboratory culture of Ankistrodesmus gracilis (Reinsch Korshikov (Chlorophyceae = Utilização de meios alternativos e diferentes tipos de recipientes no cultivo de Ankistrodesmus gracilis (Reinsch Korshikov (Chlorophyceae em laboratório.

Directory of Open Access Journals (Sweden)

Lucia Helena Sipauba-Tavares

2011-07-01

Full Text Available A laboratory culture of Ankistrodesmus gracilis algae was evaluated by studying the biology of the species and its chemical composition in a traditional medium (CHU12 and in two alternative culture media, NPK (20-5-20 and macrophyte (Eichhornia crassipes + NPK, in three different types of recipients (fiberglass, carboy and plastic bag. First peak in the growth curve of Ankistrodesmus gracilis occurred on the ninth day in macrophyte + NPK medium (74.16 x 105 cells mL-1 in a fiberglass recipient. However, highest density (p 0.05 in culture media in the three recipients. Protein and fiber were similar (p > 0.05 in the treatments, but lipids were higher (p O objetivo do estudo foi avaliar os aspectos biológicos e a composição química da alga Ankistrodesmus gracilis em laboratório utilizando um meio tradicional (CHU12 e dois meios alternativos, NPK (20-5-20 e macrófita (Eichhornia crassipes + NPK em três diferentes tipos de recipientes (cuba de fibra de vidro translúcido, garrafões e saco plástico. O primeiro pico de densidade celular de Ankistrodesmus gracilis ocorreu no nono dia da curva de crescimento em meio macrófita+NPK (74,16 x 105 células mL-1 no recipiente de fibra de vidro, porém a maior densidade (p 0,05 nos três recipientes e meios de cultivo. Os teores de proteína e fibra foram similares (p > 0,05 nos tratamentos utilizados, já os de lipídios foram mais elevados (p < 0,05 no meio NPK. Os teores médios de nitrato, amônia, fósforo total e ortofosfato estiveram acima de 1 mg L-1 no meio NPK (p < 0,01. Os resultados obtidos neste estudo indicam a possibilidade do uso de meios alternativos como o NPK e macrophyte +NPK para o cultivo de A. gracilis em larga escala cultivados nos três tipos de recipientes, porém, em saco plástico o custo é baixo e ocupa menos espaço em cultivo de laboratório.

Microalgae: An alternative as sustainable source of biofuels?

International Nuclear Information System (INIS)

Amaro, Helena M.; Macedo, Ângela C.; Malcata, F. Xavier

2012-01-01

In recent decades, the world has been confronted with an energy crisis associated with irreversible depletion of traditional sources of fossil fuels, coupled with atmospheric accumulation of greenhouse gases that cause global warming. The urgent need to replace traditional fuels led to emergence of biodiesel and biohydrogen as interesting alternatives, both of which can be obtained via microalga-mediated routes. Microalgae are ubiquitous eukaryotic microorganisms, characterized by a remarkable metabolic plasticity. Their oil productivities are much higher than those of higher terrestrial plants, and they do not require high quality agricultural land. Microalgae may indeed be cultivated in brackish and wastewaters that provide suitable nutrients (e.g. NH 4 + ,NO 3 − andPO 4 3− ), at the expense of only sunlight and atmospheric CO 2 . On the other hand, metabolic engineering permits release of molecular hydrogen also via photosynthetic routes, which will easily be converted to electricity in fuel cells or mechanical power in explosion engines, with only water vapor as exhaust product in both cases. However, large-scale implementation of microalga-based systems to manufacture biodiesel and biohydrogen has been economically constrained by their still poor volumetric efficiencies, which imply excessively high costs when compared with current petrofuel prices. Technological improvements are accordingly critical, both on the biocatalyst and the bioreactor levels. The current bottlenecks that have apparently precluded full industrial exploitation of microalgae cells are critically discussed here, viz. those derived from the scarce knowledge on the mechanisms that control regulation of gene expression, the reduced number of species subjected to successful genetic transformation, the relatively low cell density attainable, the poor efficiency in harvesting, and the difficulties in light capture and use. Therefore, this paper provides an overview of the feasibility of

Assessment of microalgae-influenced biodeterioration of concrete ...

African Journals Online (AJOL)

The aim of this study was to isolate microalga involved in the biodeterioration of concrete structures. The growth of algae was monitored between day 1 and 18 using a spectrophotometer (Spectronic 721 model) at varying pH (4.2 and 9.4). To identify the microalgae, aliquots of the isolates was placed on microscope slides ...

Review on biofuel oil and gas production processes from microalgae

International Nuclear Information System (INIS)

Amin, Sarmidi

2009-01-01

Microalgae, as biomass, are a potential source of renewable energy, and they can be converted into energy such as biofuel oil and gas. This paper presents a brief review on the main conversion processes of microalgae becoming energy. Since microalgae have high water content, not all biomass energy conversion processes can be applied. By using thermochemical processes, oil and gas can be produced, and by using biochemical processes, ethanol and biodiesel can be produced. The properties of the microalgae product are almost similar to those of offish and vegetable oils, and therefore, it can be considered as a substitute of fossil oil.

Advances in Microalgae-Derived Phytosterols for Functional Food and Pharmaceutical Applications

Science.gov (United States)

Luo, Xuan; Su, Peng; Zhang, Wei

2015-01-01

Microalgae contain a variety of bioactive lipids with potential applications in aquaculture feed, biofuel, food and pharmaceutical industries. While microalgae-derived polyunsaturated fatty acid (PUFA) and their roles in promoting human health have been extensively studied, other lipid types from this resource, such as phytosterols, have been poorly explored. Phytosterols have been used as additives in many food products such as spread, dairy products and salad dressing. This review focuses on the recent advances in microalgae-derived phytosterols with functional bioactivities and their potential applications in functional food and pharmaceutical industries. It highlights the importance of microalgae-derived lipids other than PUFA for the development of an advanced microalgae industry. PMID:26184233

Chemical analysis, antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

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Meriem El Kolli

2016-01-01

Conclusions: D. gracilis EO showed potent antimicrobial and anti-oxidative activities and had acted on the cytoplasm membrane. These activities could be exploited in the food industry for food preservation.

Heterotrophic cultivation of microalgae for production of biodiesel.

Science.gov (United States)

Mohamed, Mohd Shamzi; Wei, Lai Zee; Ariff, Arbakariya B

2011-08-01

High cell density cultivation of microalgae via heterotrophic growth mechanism could effectively address the issues of low productivity and operational constraints presently affecting the solar driven biodiesel production. This paper reviews the progress made so far in the development of commercial-scale heterotrophic microalgae cultivation processes. The review also discusses on patentable concepts and innovations disclosed in the past four years with regards to new approaches to microalgal cultivation technique, improvisation on the process flow designs to economically produced biodiesel and genetic manipulation to confer desirable traits leading to much valued high lipid-bearing microalgae strains.

Potential of microalgae in the bioremediation of water with chloride content

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M. E. Ramírez

2017-10-01

Full Text Available Abstract In this work it was carried out the bioremediation of water containing chlorides with native microalgae (MCA provided by the Centre for study and research in biotechnology (CIBIOT at Universidad Pontificia Bolivariana. Microalgae presented an adaptation to the water and so the conditions evaluated reaching a production of CO2 in mg L-1 of 53.0, 26.6, 56.0, 16.0 and 30.0 and chloride removal efficiencies of 16.37, 26.03, 40.04, 25.96 and 20.25% for microalgae1, microalgae2, microalgae3, microalgae4 and microalgae5 respectively. Water bioremediation process was carried out with content of chlorides in fed batch system with an initial concentration of chlorides of 20585 mg L-1 every 2 days. The Manipulated variables were: the flow of MCA3 (10% inoculum for test one; NPK flow for test two, and flow of flow of MCA3+0.5 g L-1 NPK. Chloride removal efficiencies were 66.88%, 63.41% and 66.98% for test one, two and three respectively, for a total bioprocess time of 55 days.

Hydrothermal Disintegration and Extraction of Different Microalgae Species

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Michael Kröger

2018-02-01

Full Text Available For the disintegration and extraction of microalgae to produce lipids and biofuels, a novel processing technology was investigated. The utilization of a hydrothermal treatment was tested on four different microalgae species (Scenedesmus rubescens, Chlorella vulgaris, Nannochloropsis oculata and Arthorspira platensis (Spirulina to determine whether it has an advantage in comparison to other disintegration methods for lipid extraction. It was shown, that hydrothermal treatment is a reasonable opportunity to utilize microalgae without drying and increase the lipid yield of an algae extraction process. For three of the four microalgae species, the extraction yield with a prior hydrothermal treatment elevated the lipid yield up to six times in comparison to direct extraction. Only Scenedesmus rubescens showed a different behaviour. Reason can be found in the different cell wall of the species. The investigation of the differences in cell wall composition of the used species indicate that the existence of algaenan as a cell wall compound plays a major role in stability.

Analysis of microalgae pellets combustion in a circulating fluidized-bed

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Kosowska-Golachowska Monika

2017-01-01

Full Text Available Microalgae are expected to become an important source of highvalue products with several applications in a large number of areas of biotechnology and, especially, in biofuels production. The increasing interest in microalgae as a source of biofuel (so-called third generation biofuel is due to the several advantages. The objective of this study was to investigate combustion characteristics of microalgae (Oscillatoria sp. pellets burnt in a circulating fluidized-bed (CFB in terms of sample temperature profiles, ignition time, ignition temperature, devolatilization time and the burnout time. Spherical 10-mm microalgae pellets were tested at temperature of 850°C in a 12-kW bench-scale CFB combustor.

Development of microalgae biomaterials with enhanced antioxidant activity using electron beam

Energy Technology Data Exchange (ETDEWEB)

Kim, Younghwa; Park, Hyunjin; Choi, Soojeong; Lee, Jaehwa [Silla Univ., Busan (Korea, Republic of)

2013-07-01

By increasing the antioxidant products (e. g. antioxidant enzyme, carotenoid, phycobiliproteins, chlorophyll, lipid phenolic compounds, etc.) in microalgae, it could be useful for industry. In this study, mutants of fresh water microalgae Arthrospira platensis (A. platensis) by high energy electron beam were isolated and characterized. Those selected mutants showed higher growth rate than parental strain. The antioxidant enzyme activity (SOD and POD), flavonoid, phenolic compound and phycocyanin of mutants were increased about 2 times compared to wild type. Moreover, DPPH radical scavenging activity was increased about 20%. Microalgae species with improved growth rate and enhanced active compounds make the commercial process more feasible in industry. Using microalgae mutants with increased antioxidant products, it is useful to develop microalgae biomaterials for neutraceuticals.

Development of microalgae biomaterials with enhanced antioxidant activity using electron beam

International Nuclear Information System (INIS)

Kim, Younghwa; Park, Hyunjin; Choi, Soojeong; Lee, Jaehwa

2013-01-01

By increasing the antioxidant products (e. g. antioxidant enzyme, carotenoid, phycobiliproteins, chlorophyll, lipid phenolic compounds, etc.) in microalgae, it could be useful for industry. In this study, mutants of fresh water microalgae Arthrospira platensis (A. platensis) by high energy electron beam were isolated and characterized. Those selected mutants showed higher growth rate than parental strain. The antioxidant enzyme activity (SOD and POD), flavonoid, phenolic compound and phycocyanin of mutants were increased about 2 times compared to wild type. Moreover, DPPH radical scavenging activity was increased about 20%. Microalgae species with improved growth rate and enhanced active compounds make the commercial process more feasible in industry. Using microalgae mutants with increased antioxidant products, it is useful to develop microalgae biomaterials for neutraceuticals

Taxonomy of the phyllosoma of Panulirus inflatus (Bouvier, 1895 and P. gracilis Streets, 1871, based on morphometry and molecular analysis

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Isabel Muñoz-García

Full Text Available Analysis of wild phyllosoma of Panulirus inflatus (Bouvier, 1895 and P. gracilis Streets, 1871 determined the morphological structures having taxonomic value for differentiation of the two species, in addition to the structures described previously. Of 54 phyllosoma, species identity was confirmed by PCR-restriction fragment length polymorphism (RFLP on 42 P. inflatus and 4 P. gracilis, for which morphology and morphometric measurements were taken. Morphological analysis found subexopodal spines, spines at the base of pereopods 1 and 2, and the mandibles are structures of taxonomic value for differentiating the two species. Morphometric data did not allow differentiation.

Biofuels from Microalgae

NARCIS (Netherlands)

Barbosa, M.J.; Wijffels, R.H.

2013-01-01

Microalgae are a promising feedstock for sustaineble production of biofuela due to their unique capacity to reach high lipid productivities. Although the promises are there, production costs and energy requirements are high and the technology is still ammature for the production of bulk products. It

From tiny microalgae to huge biorefineries

OpenAIRE

Gouveia, L.

2014-01-01

Microalgae are an emerging research field due to their high potential as a source of several biofuels in addition to the fact that they have a high-nutritional value and contain compounds that have health benefits. They are also highly used for water stream bioremediation and carbon dioxide mitigation. Therefore, the tiny microalgae could lead to a huge source of compounds and products, giving a good example of a real biorefinery approach. This work shows and presents examples of experimental...

Potential of microalgae in the bioremediation of water with chloride content

OpenAIRE

Ramírez, M. E.; Vélez, Y. H.; Rendón, L.; Alzate, E.

2017-01-01

Abstract In this work it was carried out the bioremediation of water containing chlorides with native microalgae (MCA) provided by the Centre for study and research in biotechnology (CIBIOT) at Universidad Pontificia Bolivariana. Microalgae presented an adaptation to the water and so the conditions evaluated reaching a production of CO2 in mg L-1 of 53.0, 26.6, 56.0, 16.0 and 30.0 and chloride removal efficiencies of 16.37, 26.03, 40.04, 25.96 and 20.25% for microalgae1, microalgae2, microalg...

Microalgae community shifts during the biogas upgrading in an alkaline open photobioreactor.

Science.gov (United States)

Granada-Moreno, C I; Aburto-Medina, A; de Los Cobos Vasconcelos, D; González-Sánchez, A

2017-10-01

To achieve the functional specialization of a microalgae community through operational tuning of an open photobioreactor used for biogas upgrading under alkaline conditions. An open photobioreactor was inoculated with an indigenous microalgae sample from the Texcoco Soda Lake. A microalgae community was adapted to fix CO 2 from synthetic biogas through different culture conditions reaching a maximum of 220 mg CO 2  l -1 per day. Picochlorum sp. and Scenedesmus sp. were identified as the prominent microalgae genera by molecular fingerprinting (partial sequencing of 16S rRNA and 18S rRNA genes) but only the first was detected by microscopy screening. Changes in the microalgae community profile were monitored by a range-weighted richness index, reaching the lowest value when biogas was upgraded. A robust microalgae community in the open photobioreactor was obtained after different culture conditions. The specialization of microalgae community for CO 2 fixation under H 2 S presence was driven by biogas upgrading conditions. The alkaline conditions enhance the CO 2 absorption from biogas and could optimize specialized microalgae communities in the open photobioreactor. Denaturing gradient gel electrophoresis fingerprinting and richness index comparison are useful methods for the evaluation of microalgae community shifts and photosynthetic activity performance, particularly in systems intended for CO 2 removal from biogas where the CO 2 assimilation potential can be related to the microbial richness. © 2017 The Society for Applied Microbiology.

With a flick of the lid: a novel trapping mechanism in Nepenthes gracilis pitcher plants.

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Ulrike Bauer

Full Text Available Carnivorous pitcher plants capture prey with modified leaves (pitchers, using diverse mechanisms such as 'insect aquaplaning' on the wet pitcher rim, slippery wax crystals on the inner pitcher wall, and viscoelastic retentive fluids. Here we describe a new trapping mechanism for Nepenthes gracilis which has evolved a unique, semi-slippery wax crystal surface on the underside of the pitcher lid and utilises the impact of rain drops to 'flick' insects into the trap. Depending on the experimental conditions (simulated 'rain', wet after 'rain', or dry, insects were captured mainly by the lid, the peristome, or the inner pitcher wall, respectively. The application of an anti-slip coating to the lower lid surface reduced prey capture in the field. Compared to sympatric N. rafflesiana, N. gracilis pitchers secreted more nectar under the lid and less on the peristome, thereby directing prey mainly towards the lid. The direct contribution to prey capture represents a novel function of the pitcher lid.

Evaluation of the Antioxidant Activity of Cell Extracts from Microalgae

OpenAIRE

F. Xavier Malcata; Pedro Moradas-Ferreira; Paula Tamagnini; A. C. Silva Ferreira; Maria S. Gião; Rui Seabra; A. Catarina Guedes

2013-01-01

A growing market for novel antioxidants obtained from non-expensive sources justifies educated screening of microalgae for their potential antioxidant features. Characterization of the antioxidant profile of 18 species of cyanobacteria (prokaryotic microalgae) and 23 species of (eukaryotic) microalgae is accordingly reported in this paper. The total antioxidant capacity, accounted for by both water- and lipid-soluble antioxidants, was evaluated by the (radical cation) ABTS method. For complem...

Effective cultivation of microalgae for biofuel production: a pilot-scale evaluation of a novel oleaginous microalga Graesiella sp. WBG-1.

Science.gov (United States)

Wen, Xiaobin; Du, Kui; Wang, Zhongjie; Peng, Xinan; Luo, Liming; Tao, Huanping; Xu, Yan; Zhang, Dan; Geng, Yahong; Li, Yeguang

2016-01-01

Commercial production of microalgal biodiesel is not yet economically viable, largely because of low storage lipid yield in microalgae mass cultivation. Selection of lipid-rich microalgae, thus, becomes one of the key research topics for microalgal biodiesel production. However, the laboratory screening protocols alone cannot predict the ability of the strains to dominate and perform in outdoor ponds. Comprehensive assessment of microalgae species should be performed not only under the laboratory conditions, but also in the fields. Laboratory investigations using a bubbled column photobioreactor indicated the microalga Graesiella sp. WBG-1 to be the most productive species among the 63 Chlorophyta strains. In a 10 L reactor, mimicking the industrial circular pond, Graesiella sp. WBG-1 produced 12.03 g biomass m(-2) day(-1) and 5.44 g lipids (45.23 % DW) m(-2) day(-1) under 15 mol m(-2) day(-1) artificial light irradiations. The lipid content decreased to ~34 % DW when the microalga was cultured in 30 L tank PBR under natural solar irradiations, but the decline of lipid content with scaling up was the minimum among the tested strains. Based on these results, the microalga was further tested for its lipid production and culture competitiveness using a pilot-scale raceway pond (200 m(2) illuminated area, culture volume 40,000 L). Consequently, Graesiella sp. WBG-1 maintained a high lipid content (33.4 % DW), of which ~90 % was storage TAGs. Results from the outdoor experiments indicated the nice adaptability of the Graesiella sp. WBG-1 to strong and fluctuating natural solar irradiance and temperature, and also demonstrated several other features, such as large cell size (easy for harvest and resistant to swallow by protozoa) and tolerance to high culture pH (helpful to CO2 fixation). Graesiella sp. WBG-1 was a promising strain capable of accumulating large amount of storage lipid under nature solar irradiance and temperature. The high lipid content

Can Microalgae Remove Pharmaceutical Contaminants from Water?

Science.gov (United States)

Xiong, Jiu-Qiang; Kurade, Mayur B; Jeon, Byong-Hun

2018-01-01

The increase in worldwide water contamination with numerous pharmaceutical contaminants (PCs) has become an emerging environmental concern due to their considerable ecotoxicities and associated health issues. Microalgae-mediated bioremediation of PCs has recently gained scientific attention, as microalgal bioremediation is a solar-power driven, ecologically comprehensive, and sustainable reclamation strategy. In this review, we comprehensively describe the current research on the possible roles and applications of microalgae for removing PCs from aqueous media. We summarize several novel approaches including constructing microbial consortia, acclimation, and cometabolism for enhanced removal of PCs by microalgae, which would improve practical feasibility of these technologies. Some novel concepts for degrading PCs using integrated processes and genetic modifications to realize algal-based bioremediation technologies are also recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

Wastewater nutrient removal in a mixed microalgae-bacteria culture: effect of light and temperature on the microalgae-bacteria competition.

Science.gov (United States)

González-Camejo, J; Barat, R; Pachés, M; Murgui, M; Seco, A; Ferrer, J

2018-02-01

The aim of this study was to evaluate the effect of light intensity and temperature on nutrient removal and biomass productivity in a microalgae-bacteria culture and their effects on the microalgae-bacteria competition. Three experiments were carried out at constant temperature and various light intensities: 40, 85 and 125 µE m -2  s -1 . Other two experiments were carried out at variable temperatures: 23 ± 2°C and 28 ± 2°C at light intensity of 85 and 125 µE m -2  s -1 , respectively. The photobioreactor was fed by the effluent from an anaerobic membrane bioreactor. High nitrogen and phosphorus removal efficiencies (about 99%) were achieved under the following operating conditions: 85-125 µE m -2  s -1 and 22 ± 1°C. In the microalgae-bacteria culture studied, increasing light intensity favoured microalgae growth and limited the nitrification process. However, a non-graduated temperature increase (up to 32°C) under the light intensities studied caused the proliferation of nitrifying bacteria and the nitrite and nitrate accumulation. Hence, light intensity and temperature are key parameters in the control of the microalgae-bacteria competition. Biomass productivity significantly increased with light intensity, reaching 50.5 ± 9.6, 80.3 ± 6.5 and 94.3 ± 7.9 mgVSS L -1  d -1 for a light intensity of 40, 85 and 125 µE m -2  s -1 , respectively.

Effect of chromium on the fatty acid composition of two strains of Euglena gracilis

Energy Technology Data Exchange (ETDEWEB)

Rocchetta, Iara [Departamento de Biodiversidad y Biologia Experimental, Universidad de Buenos Aires, Pab. II, Ciudad Universitaria, 1428 Buenos Aires (Argentina)]. E-mail: rocchetta@bg.fcen.uba.ar; Mazzuca, Marcia [Departamento de Quimica, Facultad de Ciencias Naturales, Universidad de Patagonia, Comodoro Rivadavia, Chubut (Argentina); Conforti, Visitacion [Departamento de Biodiversidad y Biologia Experimental, Universidad de Buenos Aires, Pab. II, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Ruiz, Laura [Departamento de Biodiversidad y Biologia Experimental, Universidad de Buenos Aires, Pab. II, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Balzaretti, Vilma [Departamento de Quimica, Facultad de Ciencias Naturales, Universidad de Patagonia, Comodoro Rivadavia, Chubut (Argentina); Rios de Molina, Maria del Carmen [Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pab. II, Ciudad Universitaria, 1428 Buenos Aires (Argentina)

2006-05-15

The effect of hexavalent chromium on fatty acid composition was studied in two strains of Euglena gracilis; UTEX 753 (from the Culture Collection of Algae of Texas University, USA) and MAT (isolated from a highly polluted River). Both were grown in photoauxotrophic and photoheterotrophic conditions and exposed to two metal concentrations, one below and one above IC{sub 5}. The high malondialdehyde (MDA) levels (3 to 7-fold) obtained with chromium concentration above IC{sub 5}, suggested the existence of metal-induced lipid peroxidation. Total lipid content increased only with concentration below IC{sub 5}, whereas it was inhibited by higher metal concentration. Photoheterotrophic control strains exhibited a significantly higher proportion of saturated and polyunsaturated fatty acids. Polyunsaturated acids were most affected by chromium, especially those related to chloroplast structures. Ultra-structure studies showed clear thylakoid disorganization in all treated cells. The results indicate that hexavalent chromium affects levels of fatty acids, especially those related to photosynthetic activity. - Fatty acid evaluation in the presence of chromium in Euglena gracilis grown in different culture conditions.

Effect of chromium on the fatty acid composition of two strains of Euglena gracilis

International Nuclear Information System (INIS)

Rocchetta, Iara; Mazzuca, Marcia; Conforti, Visitacion; Ruiz, Laura; Balzaretti, Vilma; Rios de Molina, Maria del Carmen

2006-01-01

The effect of hexavalent chromium on fatty acid composition was studied in two strains of Euglena gracilis; UTEX 753 (from the Culture Collection of Algae of Texas University, USA) and MAT (isolated from a highly polluted River). Both were grown in photoauxotrophic and photoheterotrophic conditions and exposed to two metal concentrations, one below and one above IC 5 . The high malondialdehyde (MDA) levels (3 to 7-fold) obtained with chromium concentration above IC 5 , suggested the existence of metal-induced lipid peroxidation. Total lipid content increased only with concentration below IC 5 , whereas it was inhibited by higher metal concentration. Photoheterotrophic control strains exhibited a significantly higher proportion of saturated and polyunsaturated fatty acids. Polyunsaturated acids were most affected by chromium, especially those related to chloroplast structures. Ultra-structure studies showed clear thylakoid disorganization in all treated cells. The results indicate that hexavalent chromium affects levels of fatty acids, especially those related to photosynthetic activity. - Fatty acid evaluation in the presence of chromium in Euglena gracilis grown in different culture conditions

MICROALGAS E SEU POTENCIAL DE USO

OpenAIRE

Barcellos, Amanda Desireux; UFBA; Barreto, Antonio Geraldo da Silva Sá; UFBA; Machado, Bruna Aparecida Souza; UFBA; Druzian, Janice Izabel; UFBA

2014-01-01

As microalgas são organismos predominantemente microscópicos unicelulares, procariontes ou eucariontes, dotados de pigmentos e fotoautotróficos. Estes seres possuem um alto potencial biológico, ecológico e econômico. O objetivo desta prospecção tecnológica foi identificar as patentes, teses e artigos científicos referentes a microalgas quanto ao seu emprego nos mais diversos setores, bem como sua tecnologia de cultivo. Para tanto, foi realizada uma pesquisa aos bancos de dados de patentes nac...

Biotechnological production of value-added carotenoids from microalgae: Emerging technology and prospects.

Science.gov (United States)

Wichuk, Kristine; Brynjólfsson, Sigurður; Fu, Weiqi

2014-01-01

We recently evaluated the relationship between abiotic environmental stresses and lutein biosynthesis in the green microalga Dunaliella salina and suggested a rational design of stress-driven adaptive evolution experiments for carotenoids production in microalgae. Here, we summarize our recent findings regarding the biotechnological production of carotenoids from microalgae and outline emerging technology in this field. Carotenoid metabolic pathways are characterized in several representative algal species as they pave the way for biotechnology development. The adaptive evolution strategy is highlighted in connection with enhanced growth rate and carotenoid metabolism. In addition, available genetic modification tools are described, with emphasis on model species. A brief discussion on the role of lights as limiting factors in carotenoid production in microalgae is also included. Overall, our analysis suggests that light-driven metabolism and the photosynthetic efficiency of microalgae in photobioreactors are the main bottlenecks in enhancing biotechnological potential of carotenoid production from microalgae.

Consequences of acclimation to Microcystis on the selective feeding behavior of the calanoid copepod Eudiaptomus gracilis

NARCIS (Netherlands)

Ger, K.A.; Panosso, R.; Lürling, M.

2011-01-01

We tested the hypothesis that calanoid copepods would adapt to extended periods of Microcystis exposure by increasing selective feeding on alternative food. Copepod (Eudiaptomus gracilis) clearance rates were compared before and after a 5-d acclimation to Microcystis aeruginosa using paired food

Microalgae as a raw material for biofuels production.

Science.gov (United States)

Gouveia, Luisa; Oliveira, Ana Cristina

2009-02-01

Biofuels demand is unquestionable in order to reduce gaseous emissions (fossil CO(2), nitrogen and sulfur oxides) and their purported greenhouse, climatic changes and global warming effects, to face the frequent oil supply crises, as a way to help non-fossil fuel producer countries to reduce energy dependence, contributing to security of supply, promoting environmental sustainability and meeting the EU target of at least of 10% biofuels in the transport sector by 2020. Biodiesel is usually produced from oleaginous crops, such as rapeseed, soybean, sunflower and palm. However, the use of microalgae can be a suitable alternative feedstock for next generation biofuels because certain species contain high amounts of oil, which could be extracted, processed and refined into transportation fuels, using currently available technology; they have fast growth rate, permit the use of non-arable land and non-potable water, use far less water and do not displace food crops cultures; their production is not seasonal and they can be harvested daily. The screening of microalgae (Chlorella vulgaris, Spirulina maxima, Nannochloropsis sp., Neochloris oleabundans, Scenedesmus obliquus and Dunaliella tertiolecta) was done in order to choose the best one(s), in terms of quantity and quality as oil source for biofuel production. Neochloris oleabundans (fresh water microalga) and Nannochloropsis sp. (marine microalga) proved to be suitable as raw materials for biofuel production, due to their high oil content (29.0 and 28.7%, respectively). Both microalgae, when grown under nitrogen shortage, show a great increase (approximately 50%) in oil quantity. If the purpose is to produce biodiesel only from one species, Scenedesmus obliquus presents the most adequate fatty acid profile, namely in terms of linolenic and other polyunsaturated fatty acids. However, the microalgae Neochloris oleabundans, Nannochloropsis sp. and Dunaliella tertiolecta can also be used if associated with other

Fungitoxicidade dos extratos vegetais e do óleo essencial de Lippia gracilis Schauer sobre o fungo Monosporascus cannonballus Pollack e Uecker

Directory of Open Access Journals (Sweden)

Luciana Cristina Borges Fernandes

2015-06-01

Full Text Available Alecrim da Chapada (Lippia gracilis Schauer é considerada uma planta rica em óleo essencial e possui atividade antimicrobiana comprovada, devido aos monoterpenos fenólicos carvacrol e timol. O objetivo deste trabalho foi avaliar o efeito in vitro do óleo essencial e dos extratos etanólicos de raízes e folhas de L. gracilis no controle do fungo Monosporasccus cannonballus, causador do colapso do meloeiro. O extratos foram testados nas concentrações de 2500, 5000 e 7500 ppm e o óleo essencial de L. gracilis foi avaliado nas concentrações 255, 340 e 425 ppm tendo também um controle positivo com o fungicida comercial Captan(r e um negativo apenas com meio BDA (batata, dextrose, ágar. Discos de micélio com 3 mm de diâmetro foram inoculados no centro de placas de Petri e as medições do crescimento micelial do fungo foram realizadas 48 horas após a montagem do experimento. Verificou-se que o óleo essencial de L. gracilis nas três concentrações testadas foi eficiente para o controle do fungo, com percentuais de inibição de 100%, em comparação ao tratamento com o controle negativo (0% que não apresentou inibição. O extrato radicular, nas concentrações de 5000 e 7500 ppm e o extrato foliar na concentração de 7500 ppm também proporcionaram um percentual de inibição de 100%.

Spermiogenesis and spermatozoon of the tapeworm Parabothriocephalus gracilis (Bothriocephalidea): Ultrastructural and cytochemical studies

Czech Academy of Sciences Publication Activity Database

Šípková, Lenka; Levron, Céline; Freeman, M.; Scholz, Tomáš

2010-01-01

Roč. 55, č. 1 (2010), s. 58-65 ISSN 1230-2821 R&D Projects: GA ČR GP524/07/P039; GA ČR GA524/08/0885; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Eucestoda * Bothriocephalidea * Parabothriocephalus gracilis * spermiogenesis * spermatozoon * ultrastructure Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.144, year: 2010

Novel protocol for lutein extraction from microalga Chlorella vulgaris

DEFF Research Database (Denmark)

D'Este, Martina; De Francisci, Davide; Angelidaki, Irini

2017-01-01

Lutein is a pigment generally extracted from marigold flowers. However, lutein is also found in considerable amounts in microalgae. In this study a novel method was developed to improve the extraction efficiency of lutein from microalga C. vulgaris. Differently from conventional methods, ethanol...

Review of Microalgae Harvesting via Co-Pelletization with Filamentous Fungus

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Bo Hu

2013-11-01

Full Text Available Cultivation of microalgae to utilize CO2 and nutrients in the wastewater to generate biofuel products is a promising research objective. However, the process faces tremendous technical difficulties, especially the harvest of microalgae cells, an economically challenging step. Several researchers recently reported co-culturing of filamentous fungi with microalgae so that microalgae cells can be co-pelletized in order to facilitate the cell harvest. This algae pelletization via the filamentous fungi represents an innovative approach to address both the cost and sustainability issues in algae biofuel production and also has potential with direct commercial applications. This paper reviews the current research status in this area and some possible drawbacks of this method in order to provide some possible directions for the future research.

Micrositios del pasto navajita (Bouteloua gracilis en comunidades de pastizal y de matorral del Altiplano Mexicano

Directory of Open Access Journals (Sweden)

Rosalva García-Sánchez

2005-01-01

Full Text Available El objetivo de este trabajo fue determinar si hay un tipo de micrositio específico para el establecimiento de Bouteloua gracilis, con patrones recurrentes, en dos diferentes tipos de comunidades vegetales. El pasto navajita azul es una especie perenne de alto valor forrajero y resistente a la sequía. Para ello se realizó un recorrido por tres matorrales y tres pastizales del Altiplano Mexicano; los sitios estudiados fueron elegidos con base en los reportes de ejemplares colectados y herborizados. Los resultados muestran, por un lado, que en los pastizales se presentan micrositios más de tipo funcional que físico, que determinan el establecimiento de B. gracilis, debido principalmente a los altos requerimientos de humedad edáfica de las semillas para germinar y desarrollarse. El micrositio más frecuente que determina el reclutamiento de los individuos provenientes de semilla es el suelo cercano a individuos adultos de su propia especie. Por otro lado, en los matorrales se detectaron, de manera recurrente, varias condiciones de micrositio para la especie y se observó que el tipo de micrositio es determinante, tanto para el establecimiento como para el crecimiento de este y otros pastos; también, el estudio mostró que en comunidades de matorral existe una mayor diversidad de micrositios que en los pastizales, por lo que se concluye que los individuos de B. gracilis, en los matorrales, crecen asociados a micrositios específicos que le brindan protección contra la desecación.

Release of hand burn contracture: comparing the ALT perforator flap with the gracilis free flap with split skin graft.

Science.gov (United States)

Misani, M; Zirak, C; Hau, Lê Thua Trung; De Mey, A; Boeckx, W

2013-08-01

The use of microsurgery in the management of burn sequelae is not a new idea. According to the properties of various types of free flaps different goals can be achieved or various additional procedures have to be combined. We report the comparison of two different free flaps on a single patient for reconstruction of both upper extremities for burn sequelae. A 1-year-old child sustained severe burns on both hands, arms and thorax and was initially only treated conservatively. This resulted in severe contractures. At the age of 4-years a free gracilis flap was selected for reconstruction of his left hand and a free anterolateral thigh flap for the right hand. We noticed a better functional and esthetic result for the gracilis flap associated with a shorter operative time and a minor donor site morbidity. The intraoperative technique and time, postoperative complications, functional and esthetic results and donor site morbidities were studied in the two types of flaps chosen. A review of literature was also performed. Our experience reported a better success of the gracilis muscle flap covered with a split skin graft compared to the anterolateral thigh flap in the reconstruction of hand function after severe burn sequelae. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

Efficient recovery of uranium using genetically improved microalgae; Recuperacion eficaz de uranio utilizando microalgas geneticamente mejoradas

Energy Technology Data Exchange (ETDEWEB)

Lopez-Rodas, V.; Conde Vilda, E.; Garcia-Balboa, C.

2015-07-01

We propose an alternative process for the efficient recovery of dissolved uranium based on genetically improved microalgae. We isolate Chlamydomonas cf. fonticola from a pond extremely contaminated by uranium (∼ 25 ppm) from ENUSA U-mine, Saelices (Salamanca, Spain). After a process of genetic improvement we obtained a strain capable to recover 115 mg of U per g of dry weight, by mean of bio-adsorption on the cell wall (mostly) and intra-cytoplasm bioaccumulation. Such a genetically improved microalgae resist extremes of acidity and pollution, but even its dead biomass is still able to recover a large amount of uranium. (Author)

Neutral lipid accumulation at elevated temperature in conditional mutants of two microalgae species

DEFF Research Database (Denmark)

Yao, Shuo; Brandt, Anders Bøving; Egsgaard, Helge

2012-01-01

Triacylglycerols, an energy storage compound in microalgae, are known to be accumulated after nitrogen starvation of microalgae cells. Microalgae could be of importance for future biodiesel production due to their fast growth rate and high oil content. In collections of temperature sensitive...... accumulation in microalgae and suggest possibilities for biodiesel production by specific induction of lipid accumulation in miroalgal cultures by cell-cycle inhibition....

Nutrient and media recycling in heterotrophic microalgae cultures.

Science.gov (United States)

Lowrey, Joshua; Armenta, Roberto E; Brooks, Marianne S

2016-02-01

In order for microalgae-based processes to reach commercial production for biofuels and high-value products such as omega-3 fatty acids, it is necessary that economic feasibility be demonstrated at the industrial scale. Therefore, process optimization is critical to ensure that the maximum yield can be achieved from the most efficient use of resources. This is particularly true for processes involving heterotrophic microalgae, which have not been studied as extensively as phototrophic microalgae. An area that has received significant conceptual praise, but little experimental validation, is that of nutrient recycling, where the waste materials from prior cultures and post-lipid extraction are reused for secondary fermentations. While the concept is very simple and could result in significant economic and environmental benefits, there are some underlying challenges that must be overcome before adoption of nutrient recycling is viable at commercial scale. Even more, adapting nutrient recycling for optimized heterotrophic cultures presents some added challenges that must be identified and addressed that have been largely unexplored to date. These challenges center on carbon and nitrogen recycling and the implications of using waste materials in conjunction with virgin nutrients for secondary cultures. The aim of this review is to provide a foundation for further understanding of nutrient recycling for microalgae cultivation. As such, we outline the current state of technology and practical challenges associated with nutrient recycling for heterotrophic microalgae on an industrial scale and give recommendations for future work.

Techno-economical evaluation of protein extraction for microalgae biorefinery

NARCIS (Netherlands)

Sari, Y.W.; Sanders, J.P.M.; Bruins, M.

2016-01-01

Due to scarcity of fossil feedstocks, there is an increasing demand for biobased fuels. Microalgae are considered as promising biobased feedstocks. However, microalgae based fuels are not yet produced at large scale at present. Applying biorefinery, not only for oil, but also for other

TECHNOLOGICAL APPLICATION OF MICROALGAE IN POWER INDUSTRY AND ENVIRONMENTAL PROTECTION

Directory of Open Access Journals (Sweden)

Ilmutdin M. Abdulagatov

2018-01-01

Full Text Available Abstract. Aim. The aim of the study is to show the possibility and efficiency of large-scale industrial production of microalgae in the Republic of Dagestan for the development of agriculture (feed for animals and poultry and other technological applications in the food and pharmaceutical industries for the production of algalin flour (eco bread, polyunsaturated fatty acids (omega-3, omega-6 physiologically necessary for humans, biologically active substances (astaxanthin, phycocyanin, new-generation antibiotics, biofuels and other high added value biotechnological products. The problems of using microalgae for bioremediation of the environment, in particular, purification of geothermal waters from phenols before discharging into the sewage system are considered. Methods. Microalgae are grown in closed and open type plants. Valuable algae components can be extracted using supercritical fluid technology of continuous action. Results. We give a comparative evaluation of the efficiency of using microalgae as a biological raw material in comparison with traditionally used oilseeds. Conclusion. For Dagestan, located on the shore of the Caspian Sea, with its warm climate and an abundance of solar and geothermal energy, the development of this technology is a task of great economic importance. The advantages of microalgae technologies are the basis for the creation of large-scale production of microalgae in southern Russia. Biotechnology in Dagestan can become not only profitable, but also a high-tech and innovative industry.

Innovative natural functional ingredients from microalgae.

Science.gov (United States)

Plaza, Merichel; Herrero, Miguel; Cifuentes, Alejandro; Ibáñez, Elena

2009-08-26

Nowadays, a wide variety of compounds such as polyphenols, polyunsaturated fatty acids (PUFA), or phytosterols obtained, for example, from wine, fish byproducts, or plants are employed to prepare new functional foods. However, unexplored natural sources of bioactive ingredients are gaining much attention since they can lead to the discovery of new compounds or bioactivities. Microalgae have been proposed as an interesting, almost unlimited, natural source in the search for novel natural functional ingredients, and several works have shown the possibility to find bioactive compounds in these organisms. Some advantages can be associated with the study of microalgae such as their huge diversity, the possibility of being used as natural reactors at controlled conditions, and their ability to produce active secondary metabolites to defend themselves from adverse or extreme conditions. In this contribution, an exhaustive revision is presented involving the research for innovative functional food ingredients from microalgae. The most interesting results in this promising field are discussed including new species composition and bioactivity and new processing and extraction methods. Moreover, the future research trends are critically commented.

A comparative study: the impact of different lipid extraction methods on current microalgal lipid research

Science.gov (United States)

2014-01-01

Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO2 extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research. PMID:24456581

Biomass of Microalgae as a Source of Renewable Energy

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Głowacka Natalia

2017-05-01

Full Text Available Algae represent a potential source of energy via anaerobic digestion. The aim of the study was to obtain the possible potential of green microalgae, which could replace the commonly used corn silage for the production of biogas in the future. The intensive construction of new biogas plants stations across Europe and the lack of arable land suitable for the cultivation of biomass for energy purposes are the fundamental reasons behind looking for the alternative raw materials for energy production as a substitute for commonly used input materials. When comparing green microalgae with conventional crops the high productivity potential (high oil content as well as the possibility of their production during the whole year can be noticed. It is necessary to find the effective way to produce biomass from green microalgae, proper for energy conversion, while ensuring the economic and environmental aspects. The interim research results mentioned in this article indicate that microalgae present appropriate alternative material for the process of anaerobic digestion.

Extremophilic micro-algae and their potential contribution in biotechnology.

Science.gov (United States)

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

2015-05-01

Micro-algae have potential as sustainable sources of energy and products and alternative mode of agriculture. However, their mass cultivation is challenging due to low survival under harsh outdoor conditions and competition from other, undesired, species. Extremophilic micro-algae have a role to play by virtue of their ability to grow under acidic or alkaline pH, high temperature, light, CO2 level and metal concentration. In this review, we provide several examples of potential biotechnological applications of extremophilic micro-algae and the ranges of tolerated extremes. We also discuss the adaptive mechanisms of tolerance to these extremes. Analysis of phylogenetic relationship of the reported extremophiles suggests certain groups of the Kingdom Protista to be more tolerant to extremophilic conditions than other taxa. While extremophilic microalgae are beginning to be explored, much needs to be done in terms of the physiology, molecular biology, metabolic engineering and outdoor cultivation trials before their true potential is realized. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microalgae, a Potential Natural Functional Food Source – a Review

Directory of Open Access Journals (Sweden)

Villarruel-López Angélica

2017-12-01

Full Text Available Microalgae are a group of microorganisms used in aquaculture. The number of studies regarding their use as a functional food has recently increased due to their nutritional and bioactive compounds such as polysaccharides, fatty acids, bioactive peptides, and pigments. Specific microalgal glucans (polysaccharides can activate the immune system or exert antioxidant and hypocholesterolemic effects. The importance of algal lipids is based on their polyunsaturated fatty acids, their anti-inflammatory effects, their modulation of lipid pathways, and their neuroprotective action. Microalgae peptides can bind or inhibit specific receptors in cardiovascular diseases and cancer, while carotenoids can act as potent antioxidants. The beneficial biological activity will depend on the specific microalga and its chemical constituents. Therefore, knowledge of the composition of microalgae would aid in identifying, selecting, and studying their functional effects.

Microalgae as source of biofuel: technology and prospective

Science.gov (United States)

Ferraro, Angelo

2017-12-01

Microalgae are autotrophic organisms found in solitary cells or in groups of single cells connected together. Their natural environment are typically freshwater and marine systems. Microalgae produce, via photosynthesis, approximately one-half of oxygen generated on earth while simultaneously consume carbon dioxide (CO2). Among the technologies being examined to produce green fuels (e.g. biodiesel, bioethanol and syngas), microalgae are viewed by many in the scientific community as having the greatest potential to become economically viable fuels. Nevertheless, to reach economic parity with fossil fuels there are still several challenges to be tackle. These include improving harvesting and oil extraction processes as well as increasing biomass productivity and oil content. All of these challenges can be impacted by genetic, molecular, and ultimately synthetic biology techniques.

Kalanchosides A-C, new cytotoxic bufadienolides from the aerial parts of Kalanchoe gracilis.

Science.gov (United States)

Wu, Pei-Lin; Hsu, Yu-Lin; Wu, Tian-Shung; Bastow, K F; Lee, Kuo-Hsiung

2006-11-09

[Structure: see text] Three new compounds, kalanchosides A-C (1-3), as well as five known compounds, were isolated from the aerial parts of Kalanchoe gracilis. The compound structures were determined by spectroscopic methods. All eight isolated compounds showed significant cytotoxic activity against a panel of human tumor cell lines, with potency reaching the nanomolar range. However, only bryophyllin B (8) inhibited HIV replication in H9 lymphocyte cells.

[Progress in microalgae culture system for biodiesel combined with reducing carbon dioxide emission].

Science.gov (United States)

Su, Hongyang; Zhou, Xuefei; Xia, Xuefen; Sun, Zhen; Zhang, Yalei

2011-09-01

Wastewater resources, CO2 emission reduction and microalgae biodiesel are considered as current frontier fields of energy and environmental researches. In this paper, we reviewed the progress in system of microalgae culture for biodiesel production by wastewater and stack gas. Multiple factors including microalgal species, nutrition, culture methods and photobioreactor, which were crucial to the cultivation of microalgae for biodiesel production, were discussed in detail. A valuable culture system of microalgae for biodiesel production or other high value products combined with the treatment of wastewater by microalgae was put forward through the optimizations of algal species and culture technology. The culture system coupled with the treatment of wastewater, the reduction of CO2 emission with the cultivation of microalgae for biodiesel production will reduce the production cost of microalgal biofuel production and the treatment cost of wastewater simultaneously. Therefore, it would be a promising technology with important environmental value, social value and economic value to combine the treatment of wastewater with the cultivation of microalgae for biodiesel production.

The Potential Use of Marine Microalgae and Cyanobacteria in Cosmetics and Thalassotherapy

Directory of Open Access Journals (Sweden)

M. Lourdes Mourelle

2017-11-01

Full Text Available The use of microalgae and cyanobacteria for nutritional purposes dates back thousands of years; during the last few decades, microalgae culture has improved to become one of the modern biotechnologies. This has allowed high amounts of algal biomass to be obtained for use in different applications. Currently, the global production of microalgae and cyanobacteria is predominately aimed at applications with high added value given that algal biomass contains pigments, proteins, essential fatty acids, polysaccharides, vitamins, and minerals, all of which are of great interest in the preparation of natural products, both as food and in cosmetics. Hence, the bioactive components from microalgae can be incorporated in cosmetic and cosmeceutical formulations, and can help achieve benefits including the maintenance of skin structure and function. Thalassotherapy involves using seawater and all related marine elements, including macroalgae, however, there has been limited use of microalgae. Microalgae and cyanobacteria could be incorporated into health and wellness treatments applied in thalassotherapy centers due to their high concentration of biologically active substances that are of interest in skin care. This paper briefly reviews the current and potential cosmetic and cosmeceutical applications of marine microalgae and cyanobacteria compounds and also recommends its use in thalassotherapy well-being treatments.

Bionota: Bacterias promotoras de crecimiento de microalgas: una nueva aproximación en el tratamiento de aguas residuales Microalgae growth-promoting bacteria: A novel approach in wastewater treatment

Directory of Open Access Journals (Sweden)

Bashan Yoav

2003-12-01

Full Text Available Las bacterias promotoras de crecimiento en plantas (PGPB del género Azospirillum son conocidas porque mejo­ran el crecimiento de numerosas cosechas agrícolas; sin embargo, el presente trabajo pretende extender el uso de estas bacterias a "bacterias promotoras de crecimiento de microalgas" (MPGB para aumentar la capacidad de las microalgas de eliminar nutrientes de aguas residuales. La inoculación deliberada de las microalgas Chlorella spp. con PGPB de origen terrestre no ha sido reportada con anterioridad, tal vez debido al origen diferente de estos dos microorganismos. Al inmovilizar de manera conjunta Chlorella vulgaris y Azospirillum brasilense Cd en esferas de alginato, se obtuvo como resultado un aumento significativo en varios parámetros de crecimiento de la microalga, como el peso fresco y seco, el número total de células, el tamaño de las colonias de microalgas dentro de la esfera, el número de organismos por colonia y la concentración de pigmentos. Además, aumenta­ron los lípidos y la variedad de ácidos grasos. La microalga combinada con la MGPB tiene una mayor capacidad de eliminar amonio y fósforo tanto en agua residual sintética como en agua residual doméstica. Actualmente se ha estado experimentando con otras PGPB (Flavobacterium sp. Azospirillum sp. y Azotobacter sp. para propósitos acuícolas; por ejemplo aumentar el crecimiento de fitoplancton utilizado en el cultivo de carpas y estabilizar cultivos masivos de microalgas marinas utilizadas como alimento para organismos marinos, todo esto con resul­tados promisorios. Si bien el efecto de las PGPB en microorganismos acuáticos aún no ha sido suficientemente explorado, proponemos que la co-inmovilización de microalgas y bacterias promotoras de crecimiento es un medio efectivo para aumentar la población microalgal y también su capacidad de limpiar aguas residuales. Palabras clave: PGPB; microalgas; biotratamiento de aguas residuales; co

Microalgae Culture Collection: 1984-1985

Energy Technology Data Exchange (ETDEWEB)

1984-09-01

The Microalgae Culture Collection at the Solar Energy Research Institute has been established for the maintenance and distribution of strains that have been characterized for biomass fuel applications.

Anaerobic digestion of microalgae residues resulting from the biodiesel production process

International Nuclear Information System (INIS)

Ehimen, E.A.; Sun, Z.F.; Carrington, C.G.; Birch, E.J.; Eaton-Rye, J.J.

2011-01-01

The recovery of methane from post transesterified microalgae residues has the potential to improve the renewability of the 'microalgae biomass to biodiesel' conversion process as well as reduce its cost and environmental impact. This paper deals with the anaerobic digestion of microalgae biomass residues (post transesterification) using semi-continuously fed reactors. The influence of substrate loading concentrations and hydraulic retention times on the specific methane yield of the anaerobically digested microalgae residues was investigated. The co-digestion of the microalgae residues with glycerol as well as the influence of temperature was also examined. It was found that the hydraulic retention period was the most significant variable affecting methane production from the residues, with periods (>5 days) corresponding to higher energy recovery. The methane yield was also improved by a reduction in the substrate loading rates, with an optimum substrate carbon to nitrogen ratio of 12.44 seen to be required for the digestion process.

Effects of Fluctuating Environments on the Selection of High Yielding Microalgae

Energy Technology Data Exchange (ETDEWEB)

Benemann, J. R.; Tillett, D. M.

1987-02-27

Microalgae have the potential of producing biomass with a high content of lipids at high productivities using seawater or saline ground water resources. Microalgal lipids are similar to vegetable oils and suitable for processing to liquid fuels. Engineering cost analysis studies have concluded that, at a favorable site, microalgae cultivation for fuel production could be economically viable. The major uncertainties involve the microalgae themselves: biomass and lipid productivity and culture stability.

Extending the use of the gracilis muscle flap in perineal reconstruction surgery.

Science.gov (United States)

Goldie, Stephen J; Almasharqah, Riyadh; Fogg, Quentin A; Anderson, William

2016-08-01

Reconstruction of the perineum is required following oncological resections. Plastic surgical techniques can be used to restore the aesthetics and function of the perineum. The gracilis myocutaneous flap provides a substantial skin paddle, with minimal donor site morbidity. The flap is pedicled on a perforator from the medial circumflex femoral artery, giving it limited reach across the perineum. Tunnelling the flap under the adductor longus muscle may free up more of the arterial pedicle, increasing its reach. On three female cadavers, bilateral gracilis flaps were raised in the standard surgical manner, giving six flaps in total. With the flaps pedicled across the perineum, the distance from the tip of each flap was measured to the anterior superior iliac spine (ASIS). The flaps were then tunnelled under the adductor longus muscle. The distances to the ASIS were measured again. The average pedicle length was greater than 7 cm. Tunnelling the flap under the adductor longus muscle increased the reach by more than 4 cm on average. Cadaveric dissection has shown that tunnelling of the flap in a novel way increase its reach across the perineum. This additional flexibility improves its use clinically and is of benefit to plastic surgeons operating in perineal reconstruction. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Microalgae growth-promoting bacteria: A novel approach in wastewater treatment

Directory of Open Access Journals (Sweden)

Luz E. de-Bashan

2003-07-01

Full Text Available Plant growth-promoting bacteria (PGPB from the genus Azospirillum are known to enhance the growth of numerous agricultural crops. The use of these bacteria is proposed as "micro-algae-growth promoting bacteria" (MGPB for enhancing freshwater micro-algae Chlorella vulgaris and C. sorokiniana capadty to clean polluted water. The deliberate inoculation of Chlorella sp. with a terrestrial PGPB has not been reported prior to these studies, perhaps because of the different origin of the two micro-organisms. Chlorella spp. is not known to harbour any plant growth-promoting bacteria and Azospirillum sp. is rarely used for inoculation in aquatic environments. Co-immobilisation of C. vulgaris and A. brasilense Cd in small alginate beads resulted in significant increases in numerous micro-algae growth parameters. Dry and fresh weight, total number of cells, micro-algal cluster (colonies size within the bead, number of micro-algal cells per cluster and micro-algal pigments levels significantly increased. Lipids and the variety of fatty adds also significantly increased, as did the combination of micro-algae. MGPB had superior capacity for removing ammonium and phosphorus from polluted synthetic and municipal wastewaters than the micro-algae by itself. Other PGPB (i.e. Flavobacterium sp. Azospirillum sp. and Azotobacter sp. are currently being tested in aquaculture; carp farming using enhanced phytoplankton growth and stabilising mass marine micro-algae culture for use as feed for marine organisms are both retuming promising results. This aspect of PGPB effect on water micro-organisms is currently in its infancy. We pro pose that co-immobilising micro-algae and plant growth-promoting bacteria represent an effective means of increasing micro-algal populations and also their capacity for cleaning polluted water. Key words: PGPB; micro-algae; wastewater treatment; co-immobilised

Climate conditions, and changes, affect microalgae communities… should we worry?

Science.gov (United States)

Gimenez Papiol, Gemma

2018-03-01

Microalgae play a pivotal role in the regulation of Earth's climate and its cycles, but are also affected by climate change, mainly by changes in temperature, light, ocean acidification, water stratification, and precipitation-induced nutrient inputs. The changes and impacts on microalgae communities are difficult to study, predict, and manage, but there is no doubt that there will be changes. These changes will have impacts beyond microalgae communities, and many of them will be negative. Some actions are currently ongoing for the mitigation of some of the negative impacts, such as harmful algal blooms and water quality, but global efforts for reducing CO 2 emissions, temperature rises, and ocean acidification are paramount for reducing the impact of climate change on microalgae communities, and eventually, on human well-being. Integr Environ Assess Manag 2018;14:181-184. © 2018 SETAC. © 2018 SETAC.

Food commodities from microalgae

NARCIS (Netherlands)

Draaisma, R.B.; Wijffels, R.H.; Slegers, P.M.; Brentner, L.B.; Roy, A.; Barbosa, M.J.

2013-01-01

The prospect of sustainable production of food ingredients from photoautotrophic microalgae was reviewed. Clearly, there is scope for microalgal oils to replace functions of major vegetable oils, and in addition to deliver health benefits to food products. Furthermore, with a limited production

Extracellular Metabolites from Industrial Microalgae and Their Biotechnological Potential

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Lu Liu

2016-10-01

Full Text Available Industrial microalgae, as a big family of promising producers of renewable biomass feedstock, have been commercially exploited for functional food, living feed and feed additives, high-value chemicals in nutraceuticals, cosmeceuticals, and chemical reagents. Recently, microalgae have also been considered as a group that might play an important role in biofuel development and environmental protection. Almost all current products of industrial microalgae are derived from their biomass; however, large amounts of spent cell-free media are available from mass cultivation that is mostly unexploited. In this contribution we discuss that these media, which may contain a remarkable diversity of bioactive substances are worthy to be recovered for further use. Obviously, the extracellular metabolites from industrial microalgae have long been neglected in the development of production methods for valuable metabolites. With the advances in the last ten years, more and more structures and properties from extracellular metabolites have been identified, and the potential utilization over wide fields is attracting attention. Some of these extracellular metabolites can be potentially used as drugs, antioxidants, growth regulators or metal chelators. The purpose of this review is to provide an overview of the known extracellular metabolites from industrial microalgae which might be of commercial interest. The attention mainly focuses on the reports of extracellular bioactive metabolites and their potential application in biotechnology.

Gravitaxis of Euglena gracilis depends only partially on passive buoyancy

Science.gov (United States)

Richter, Peter R.; Schuster, Martin; Lebert, Michael; Streb, Christine; Häder, Donat-Peter

In darkness, the unicellular freshwater flagellate Euglena gracilis shows a pronounced negative gravitactic behavior, and the cells swim actively upward in the water column. Up to now it was unclear whether this behavior is based on a passive (physical) alignment mechanism (e.g., buoyancy due to a fore-aft asymmetry of the cell body) or on an active physiological mechanism. A sounding rocket experiment was performed in which the effect of sub-1g-accelerations (0.05, 0.08, 0.12, and 0.2g) on untreated living cells and immobilized (fixation with liquid nitrogen) cells was observed. By means of computerized image analysis the angles of the cells long axis with respect to the acceleration vector were analyzed in order to calculate and compare the reorientation kinetics of the immobilized cells versus that of the controls. In both groups, the reorientation kinetics depended on the dose, but the reorientation of the living cells was about five times faster than that of the immobilized cells. This indicates that in young cells gravitaxis can be explained by a physical mechanism only to a small extend. In older cultures, in which the cells often have a drop shaped cell body, the physical reorientation is considerably faster, and a more pronounced influence of passive alignment caused by fore/aft asymmetry (drag-gravity model) can not be excluded. In addition to these results, Euglena gracilis cells seem to respond very sensitively to small accelerations when they are applied after a longer microgravity period. The data indicate that gravitactic orientation occurred at an acceleration as low as 0.05g.

Gravitaxis in the flagellate Euglena gracilis--results from NiZeMi, clinostat and sounding rocket flights.

Science.gov (United States)

Häder, D P

1994-05-01

Many motile microorganisms including flagellates such as the green Euglena gracilis move up and down within the water column and use a number of external clues for their orientation, the most important of which may be light and gravity. The cells use positive phototaxis and negative gravitaxis to move closer to the surface of the water column which for energetic reasons is vital for their survival. However, most phytoplankton organisms cannot tolerate the bright irradiance of unfiltered solar radiation at the surface which also bleaches the photosynthetic pigments, disables the photosynthetic apparatus and impairs phototaxis, gravitaxis and motility in Euglena. Thus, it is not surprising that at higher irradiances negative phototaxis operates antagonistically to the responses described above to guide the cells into deeper water where they are protected from excessive radiation. Phototaxis and gravitaxis are not independent from one another: in a vertically positioned cuvette negative gravitaxis can be "titrated" by light impinging from above and is compensated at about 30 W m-2. While the photoreceptor for phototaxis has been identified in Euglena gracilis biochemically and spectroscopically, the gravireceptor is not yet known. Young cultures of Euglena gracilis show a positive gravitaxis, the ecological signficance of which is not yet understood while older cultures show negative gravitaxis. One hypothesis concerning the nature of graviperception is based on a passive physical process such as an asymmetric distribution of the mass within the cell. However, the observation that short term UV irradiation decreases the precision of negative gravitaxis rather indicates the involvement of an active physiological gravireceptor. Furthermore, some heavy metal ions have been found to change the direction of movement from positive to negative gravitaxis in young cells.

Biodiesel from microalgae beats bioethanol.

Science.gov (United States)

Chisti, Yusuf

2008-03-01

Renewable biofuels are needed to displace petroleum-derived transport fuels, which contribute to global warming and are of limited availability. Biodiesel and bioethanol are the two potential renewable fuels that have attracted the most attention. As demonstrated here, biodiesel and bioethanol produced from agricultural crops using existing methods cannot sustainably replace fossil-based transport fuels, but there is an alternative. Biodiesel from microalgae seems to be the only renewable biofuel that has the potential to completely displace petroleum-derived transport fuels without adversely affecting supply of food and other crop products. Most productive oil crops, such as oil palm, do not come close to microalgae in being able to sustainably provide the necessary amounts of biodiesel. Similarly, bioethanol from sugarcane is no match for microalgal biodiesel.

Cultivation Of Microalgae (Chlorella vulgaris For Biodiesel Production

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Blinová Lenka

2015-06-01

Full Text Available Production of biofuel from renewable sources is considered to be one of the most sustainable alternatives to petroleum sourced fuels. Biofuels are also viable means of environmental and economic sustainability. Biofuels are divided into four generations, depending on the type of biomass used for biofuels production. At present, microalgae are presented as an ideal third generation biofuel feedstock because of their rapid growth rate. They also do not compete with food or feed crops, and can be produced on non-arable land. Cultivation conditions (temperature, pH, light, nutrient quantity and quality, salinity, aerating are the major factors that influence photosynthesis activity and behaviour of the microalgae growth rate. In this paper, we present an overview about the effect of cultivation conditions on microalgae growth.

Multi-Product Microalgae Biorefineries: From Concept Towards Reality.

Science.gov (United States)

't Lam, G P; Vermuë, M H; Eppink, M H M; Wijffels, R H; van den Berg, C

2018-02-01

Although microalgae are a promising biobased feedstock, industrial scale production is still far off. To enhance the economic viability of large-scale microalgae processes, all biomass components need to be valorized, requiring a multi-product biorefinery. However, this concept is still too expensive. Typically, downstream processing of industrial biotechnological bulk products accounts for 20-40% of the total production costs, while for a microalgae multi-product biorefinery the costs are substantially higher (50-60%). These costs are high due to the lack of appropriate and mild technologies to access the different product fractions such as proteins, carbohydrates, and lipids. To reduce the costs, simplified processes need to be developed for the main unit operations including harvesting, cell disruption, extraction, and possibly fractionation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of biodiesel from Coelastrella sp. microalgae

Science.gov (United States)

Mansur, Dieni; Fitriady, Muhammad Arifuddin; Susilaningsih, Dwi; Simanungkalit, Sabar Pangihutan

2017-11-01

Microalgae have a wide area of usage and one of them it can be used for biodiesel production. In biodiesel production, lipids containing triglyceride or free fatty acid are converted into methyl ester through trans/esterification reactions. Lipids from microalgae can be extracted by acetone and dimethyl carbonate using homogenizer. Esterification of the lipids was investigated using various catalysts and source of methyl group. Activity of homogeneous catalyst such as HCl and H2SO4 and heterogeneous catalysts such as montmorillonit K-10 and ledgestone was investigated. Moreover, methanol and dimethyl carbonate as source of methyl group were also studied. Among of catalysts with methanol as source of methyl group, it was found that yield of crude biodiesel derived from Choelestrella Sp. microalgae was high over H2SO4 catalyst. On the other hand, over H2SO4 catalyst using dimethyl carbonate as source of methyl group, yield of crude biodiesel significant increase. However, FAME composition of crude biodiesel was high over HCl catalyst.

Experience with 32 Pelvic Fracture Urethral Defects Associated with Urethrorectal Fistulas: Transperineal Urethroplasty with Gracilis Muscle Interposition.

Science.gov (United States)

Guo, Hailin; Sa, Yinglong; Fu, Qiang; Jin, Chongrui; Wang, Lin

2017-07-01

Pelvic fracture urethral defects associated with urethrorectal fistulas are rare and difficult to repair. The aim of this study was to evaluate the efficacy of transperineal urethroplasty with gracilis muscle interposition for the repair of pelvic fracture urethral defects associated with urethrorectal fistulas. We identified 32 patients who underwent transperineal urethroplasty with gracilis muscle interposition to repair pelvic fracture urethral defects associated with urethrorectal fistulas. Patient demographics as well as preoperative, operative and postoperative data were obtained. Mean followup was 33 months (range 6 to 64). The overall success rate was 91% (29 of 32 cases). One-stage repair was successful in 17 of 18 patients (94%) using perineal anastomosis with separation of the corporeal body and in 12 of 14 (86%) using perineal anastomosis with inferior pubectomy and separation of the corporeal body. All 22 patients (100%) without a previous history of repair were successfully treated. However, only 7 of 10 patients (70%) with a previous history of failed urethroplasty and urethrorectal fistula repair were cured. Recurrent urethral strictures developed in 2 cases. One patient was treated successfully with optical internal urethrotomy and the other was treated successfully with tubed perineoscrotal flap urethroplasty. Recurrent urethrorectal fistulas associated with urethral strictures developed in an additional patient. Transperineal urethroplasty with gracilis muscle interposition is a safe and effective surgical procedure for most pelvic fracture urethral defects associated with urethrorectal fistulas. Several other factors may affect its postoperative efficiency. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Management of fourth degree obstetric perineal tear without colostomy using non - stimulated gracilis - our experience over eleven years

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Jiten Kulkarni

2016-01-01

Full Text Available Background: Although gracilis muscle transposition for faecal incontinence has been well-described method, its literature for use in obstetric perineal tear without colostomy is sparse. In this study, we have tried to analyse its use in fourth-degree obstetric perineal tears. Patients and Methods: A total of 30 patients with recto-vaginal fistula with faecal incontinence secondary to obstetric perineal tear were retrospectively studied between February 2003 and May 2014. The recto-vaginal fistula was explored, dissected and identification of sphincters was done using muscle stimulator. Fistula closure was done followed by sphincter repair, vaginal tightening procedure and single gracilis transposition. None of the patients had covering colostomy. Faecal incontinence was assessed pre- and post-operatively by digital rectal examination (single examiner, Park's score and Corman's score in all cases and using barium hold and transperineal ultrasonography, manometric studies in a few cases. The outcome was measured at an average follow-up of 8.8 months (7–24 months. Results: As per Park's score 26 patients had Grade I continence, two had Grade II and two patients had Grade III continence. Corman's score improved from fair to excellent in 26 patients. The patients in whom manometry was performed showed a remarkable rise in both resting and squeeze pressures. Two patients developed post-operative infections in upper 1/3 thigh incision site and three patients at gluteal region scar site. Conclusion: Satisfactory continence following gracilis muscle could be achieved.

Functional ingredients from microalgae

NARCIS (Netherlands)

Buono, S.; Langellotti, A.L.; Martello, A.; Rinna, F.; Fogliano, V.

2014-01-01

A wide variety of natural sources are under investigation to evaluate their possible use for new functional ingredient formulation. Some records attested the traditional and ancient use of wild harvested microalgae as human food but their cultivation for different purposes started about 40 years

Phytohormones and Effects on Growth and Metabolites of Microalgae: A Review

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Xingfeng Han

2018-04-01

Full Text Available Microalgae cultivation is booming in agriculture, aquaculture, and bioenergy sectors. A wide range of bioactive compounds with attractive properties can be produced with microalgae, including pigments, vitamins, proteins, carbohydrates, and lipids. The biofuel yields from microalgae can exceed the yields obtained with energy crops by 10–100 times. Therefore, such cultivation is promising for the regulation of the biosynthesis of microalagae with phytohormones, which can enhance the production of high-valued bioproducts. This review reports the effect of auxins, abscisic acid, cytokinins, gibberellins, and ethylene on microalgal growth and metabolites, as well as the crosstalk of different phytohormones. The use of phytohormones is also promising because it can also reduce the inputs necessary to grow the selected microalgae and maximize the yields.

Advances and perspectives in using microalgae to produce biodiesel

International Nuclear Information System (INIS)

Amaro, Helena M.; Guedes, A. Catarina; Malcata, F. Xavier

2011-01-01

Carbon-neutral renewable liquid biofuels are needed to displace petroleum-derived transport fuels in the near future - which contribute to global warming and are of a limited availability. A promising alternative is conveyed by microalgae, the oil content of which may exceed 80% (w/w DW ) - as compared with 5% of the best agricultural oil crops. However, current implementation of microalga-based systems has been economically constrained by their still poor volumetric efficiencies - which lead to excessively high costs, as compared with petrofuel prices. Technological improvements of such processes are thus critical - and this will require a multiple approach, both on the biocatalyst and bioreactor levels. Several bottlenecks indeed exist at present that preclude the full industrial exploitation of microalgal cells: the number of species that have been subjected to successful genetic transformation is scarce, which hampers a global understanding (and thus a rational design) of novel blue-biotechnological processes; the mechanisms that control regulation of gene expression are not fully elucidated, as required before effective bioprocesses based on microalgae can be scaled-up; and new molecular biology tools are needed to standardize genetic modifications in microalgae - including efficient nuclear transformation, availability of promoter or selectable marker genes, and stable expression of transgenes. On the other hand, a number of pending technological issues are also present: the relatively low microalga intrinsic lipid productivity; the maximum cell concentration attainable; the efficiency of harvest and sequential recovery of bulk lipids; and the possibility of by-product upgrade. This review briefly covers the state of the art regarding microalgae toward production of biofuels, both from the point of view of the microalgal cell itself and of the supporting bioreactor; and discusses, in a critical manner, current limitations and promising perspectives in this

Techno-Economic Assessment of Micro-Algae Production Systems

OpenAIRE

Hoffman, Justin

2016-01-01

Global oil consumption is rising at an unprecedented rate renewing interest in alternative fuels. Micro-algae represents a promising feedstock due to inherent advantages such as high solar energy efficiencies, large lipid fractions, and utilization of various waste streams including industrial flue gas. Current technological challenges have limited the commercial viability of microalgae based biofuel production systems. This study directly evaluates and compares the economic viability of biom...

The impact of Manjil and Tarik dams (Sefidroud River, southern Caspian Sea basin on morphological traits of Siah Mahi Capoeta gracilis (Pisces: Cyprinidae

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Adeleh Heidari

2013-08-01

Full Text Available It has been postulated that the building of the Manjil and Tarik dams on Sefidroud River has led to the body shape variation of Capoeta gracilis in up- and downstream populations due to the isolation. In this study, Geometric morphometric approach was used to explore body shape variations of Capoeta gracilis populations in up- and downstream Manjil and Tarik dams in Sefidroud River from south of the Caspian Sea basin. The shape of 90 individuals from three sampling sites was extracted by recording the 2-D coordinates of 13 landmark points. PCA, CVA, DFA and CA analysis were used to examine shape differences among the populations. The significant differences were found among the shape of the populations and these differences were observed in the snout, the caudal peduncle and head. The present study indicated the body shape differences in the populations of Capoeta gracilis in the Sefidroud River across the Manjil and Tarik dams, probably due to the dam construction showing anthropogenic transformation of rivers influences body shape in an aquatic organism.

Vibrating membrane filtration as improved technology for microalgae dewatering.

Science.gov (United States)

Nurra, Claudia; Clavero, Ester; Salvadó, Joan; Torras, Carles

2014-04-01

The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean pore sizes (from 7000Da to 0.2μm) were tested and compared in both filtration set-ups. Experiments were carried-out with Nannochloropsis gaditana and Phaeodactylum tricornutum microalgae. It has been demonstrated that, even if the choice of the membrane depends on its cut-off, its material and the type of microalgae filtrated, dynamic filtration is always the best technology over a conventional one. If with conventional filtration permeability values were in the vicinity of 10L/h/m(2)/bar in steady state phase, with dynamic filtration these values increased to 30L/h/m(2)/bar or more. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Lignocellulose Related Compounds on Microalgae Growth and Product Biosynthesis: A Review

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Krystian Miazek

2014-07-01

Full Text Available Microalgae contain valuable compounds that can be harnessed for industrial applications. Lignocellulose biomass is a plant material containing in abundance organic substances such as carbohydrates, phenolics, organic acids and other secondary compounds. As growth of microalgae on organic substances was confirmed during heterotrophic and mixotrophic cultivation, lignocellulose derived compounds can become a feedstock to cultivate microalgae and produce target compounds. In this review, different treatment methods to hydrolyse lignocellulose into organic substrates are presented first. Secondly, the effect of lignocellulosic hydrolysates, organic substances typically present in lignocellulosic hydrolysates, as well as minor co-products, on growth and accumulation of target compounds in microalgae cultures is described. Finally, the possibilities of using lignocellulose hydrolysates as a common feedstock for microalgae cultures are evaluated.

Efficient Anaerobic Digestion of Microalgae Biomass: Proteins as a Key Macromolecule.

Science.gov (United States)

Magdalena, Jose Antonio; Ballesteros, Mercedes; González-Fernandez, Cristina

2018-05-06

Biogas generation is the least complex technology to transform microalgae biomass into bioenergy. Since hydrolysis has been pointed out as the rate limiting stage of anaerobic digestion, the main challenge for an efficient biogas production is the optimization of cell wall disruption/hydrolysis. Among all tested pretreatments, enzymatic treatments were demonstrated not only very effective in disruption/hydrolysis but they also revealed the impact of microalgae macromolecular composition in the anaerobic process. Although carbohydrates have been traditionally recognized as the polymers responsible for the low microalgae digestibility, protease addition resulted in the highest organic matter solubilization and the highest methane production. However, protein solubilization during the pretreatment can result in anaerobic digestion inhibition due to the release of large amounts of ammonium nitrogen. The possible solutions to overcome these negative effects include the reduction of protein biomass levels by culturing the microalgae in low nitrogen media and the use of ammonia tolerant anaerobic inocula. Overall, this review is intended to evidence the relevance of microalgae proteins in different stages of anaerobic digestion, namely hydrolysis and methanogenesis.

Production of bio-jet fuel from microalgae

Science.gov (United States)

Elmoraghy, Marian

The increase in petroleum-based aviation fuel consumption, the decrease in petroleum resources, the fluctuation of the crude oil price, the increase in greenhouse gas emission and the need for energy security are motivating the development of an alternate jet fuel. Bio-jet fuel has to be a drop in fuel, technically and economically feasible, environmentally friendly, greener than jet fuel, produced locally and low gallon per Btu. Bic jet fuel has been produced by blending petro-based jet fuel with microalgae biodiesel (Fatty Acid Methyl Ester, or simply FAME). Indoor microalgae growth, lipids extraction and transetrification to biodiesel are energy and fresh water intensive and time consuming. In addition, the quality of the biodiesel product and the physical properties of the bio-jet fuel blends are unknown. This work addressed these challenges. Minimizing the energy requirements and making microalgae growth process greener were accomplished by replacing fluorescent lights with light emitting diodes (LEDs). Reducing fresh water footprint in algae growth was accomplished by waste water use. Microalgae biodiesel production time was reduced using the one-step (in-situ transestrification) process. Yields up to 56.82 mg FAME/g dry algae were obtained. Predicted physical properties of in-situ FAME satisfied European and American standards confirming its quality. Lipid triggering by nitrogen deprivation was accomplished in order to increase the FAME production. Bio-jet fuel freezing points and heating values were measured for different jet fuel to biodiesel blend ratios.

Hazard and risk of herbicides for marine microalgae

International Nuclear Information System (INIS)

Sjollema, Sascha B.; MartínezGarcía, Gema; Geest, Harm G. van der; Kraak, Michiel H.S.; Booij, Petra; Vethaak, A. Dick; Admiraal, Wim

2014-01-01

Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol ® 1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally. - Highlights: • The hazard of herbicides for microalgae is compound and species specific. • In general a low risk although occasional potential effect levels are reached. • Current legislation does not protect marine microalgae sufficiently. - The hazard of herbicides in the coastal waters is compound and species specific and although the general risk in the field is low, occasionally potential effect levels are reached

Monitoring Growth and Lipid Production of Some Egyptian Microalgae

International Nuclear Information System (INIS)

El-Baghdady, K.Z.; Zakaria, A.E.; Mousa, L.A.; Sadek, H.N.; Abd El Fatah, H.M.

2016-01-01

Microalgae bio diesel is a green and renewable energy resource. This study aims to examine growth and lipid production by various isolates of icroalgae using different growth media and lipid extraction techniques. Ten microalgae isolates were isolated from different samples collected from Egypt. The purified isolates were identified microscopically as: Lyngbya confervoides, Phormidium bohneri, Oscillatoria pseudogeminata, Amorphonostoc sp., Nostoc paludosum, Anabaena sphaerica related to cyanobacteria (blue green algae) and Chlorella vulgaris, Chlorella ellipsoidea, Scened esmusacutus acutus, Chlamydomonas globose related to green algae. These organisms were cultivated on two media: Bold's Basal Medium(BBM medium) and Blue Green Medium (BG-11 medium) to examine the favorite medium which supports the growth of each isolate In order to examine lipid production potentials by cyanobacterial isolates and green microalgae, two solvent systems were applied for lipid extraction, the first was (Chloroform - methanol 1:1 ) and the second was (Hexane-ethanol 1:1). Chlorella vulgaris and Anabaena sphaerica were selected as models of green microalgae and cyanobacteria espectively. Hexane-ethanol solvent system revealed higher lipid extraction capacity as compared to Chloroform- methanol system. A comparison between ten organisms for lipid production was carried out by the selected solvent mixture. The percentages of lipid to dry weight produced by Oscillatoria pseudogeminata and Chlamydomonas globose were 19.8% and14 .6% respectively recording the highest lipid to dry weight percentage. They can be considered as a promising lipid producing microalgae

Ratio between autoflocculating and target microalgae affects the energy-efficient harvesting by bio-flocculation

NARCIS (Netherlands)

Salim, S.; Vermuë, M.H.; Wijffels, R.H.

2012-01-01

The effect of ratio between autoflocculating and target microalgae in bio-flocculation was studied with emphasis on the recovery, sedimentation rate and energy demand for harvesting the target microalgae. When the autoflocculating microalgae Ettlia texensis, Ankistrodesmus falcatus and Scenedesmus

Biodiesel production with microalgae as feedstock: from strains to biodiesel.

Science.gov (United States)

Gong, Yangmin; Jiang, Mulan

2011-07-01

Due to negative environmental influence and limited availability, petroleum-derived fuels need to be replaced by renewable biofuels. Biodiesel has attracted intensive attention as an important biofuel. Microalgae have numerous advantages for biodiesel production over many terrestrial plants. There are a series of consecutive processes for biodiesel production with microalgae as feedstock, including selection of adequate microalgal strains, mass culture, cell harvesting, oil extraction and transesterification. To reduce the overall production cost, technology development and process optimization are necessary. Genetic engineering also plays an important role in manipulating lipid biosynthesis in microalgae. Many approaches, such as sequestering carbon dioxide from industrial plants for the carbon source, using wastewater for the nutrient supply, and maximizing the values of by-products, have shown a potential for cost reduction. This review provides a brief overview of the process of biodiesel production with microalgae as feedstock. The methods associated with this process (e.g. lipid determination, mass culture, oil extraction) are also compared and discussed.

Evaluation of the Antioxidant Activity of Cell Extracts from Microalgae

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F. Xavier Malcata

2013-04-01

Full Text Available A growing market for novel antioxidants obtained from non-expensive sources justifies educated screening of microalgae for their potential antioxidant features. Characterization of the antioxidant profile of 18 species of cyanobacteria (prokaryotic microalgae and 23 species of (eukaryotic microalgae is accordingly reported in this paper. The total antioxidant capacity, accounted for by both water- and lipid-soluble antioxidants, was evaluated by the (radical cation ABTS method. For complementary characterization of cell extracts, a deoxyribose assay was carried out, as well as a bacteriophage P22/Salmonella-mediated approach. The microalga Scenedesmus obliquus strain M2-1 exhibited the highest (p > 0.05 total antioxidant capacity (149 ± 47 AAU of intracellular extracts. Its scavenger activity correlated well with its protective effects against DNA oxidative damage induced by copper(II-ascorbic acid; and against decay in bacteriophage infection capacity induced by H2O2. Finally, performance of an Ames test revealed no mutagenic effects of the said extract.

Hydrodynamic study of an internal airlift reactor for microalgae culture.

Science.gov (United States)

Rengel, Ana; Zoughaib, Assaad; Dron, Dominique; Clodic, Denis

2012-01-01

Internal airlift reactors are closed systems considered today for microalgae cultivation. Several works have studied their hydrodynamics but based on important solid concentrations, not with biomass concentrations usually found in microalgae cultures. In this study, an internal airlift reactor has been built and tested in order to clarify the hydrodynamics of this system, based on microalgae typical concentrations. A model is proposed taking into account the variation of air bubble velocity according to volumetric air flow rate injected into the system. A relationship between riser and downcomer gas holdups is established, which varied slightly with solids concentrations. The repartition of solids along the reactor resulted to be homogenous for the range of concentrations and volumetric air flow rate studied here. Liquid velocities increase with volumetric air flow rate, and they vary slightly when solids are added to the system. Finally, liquid circulation time found in each section of the reactor is in concordance with those employed in microalgae culture.

The role of biochemical engineering in the production of biofuels from microalgae.

Science.gov (United States)

Costa, Jorge Alberto Vieira; de Morais, Michele Greque

2011-01-01

Environmental changes that have occurred due to the use of fossil fuels have driven the search for alternative sources that have a lower environmental impact. First-generation biofuels were derived from crops such as sugar cane, corn and soybean, which contribute to water scarcity and deforestation. Second-generation biofuels originated from lignocellulose agriculture and forest residues, however these needed large areas of land that could be used for food production. Based on technology projections, the third generation of biofuels will be derived from microalgae. Microalgae are considered to be an alternative energy source without the drawbacks of the first- and second-generation biofuels. Depending upon the growing conditions, microalgae can produce biocompounds that are easily converted into biofuels. The biofuels from microalgae are an alternative that can keep the development of human activity in harmony with the environment. This study aimed to present the main biofuels that can be derived from microalgae. Copyright © 2010 Elsevier Ltd. All rights reserved.

Transgene Expression in Microalgae-From Tools to Applications.

Science.gov (United States)

Doron, Lior; Segal, Na'ama; Shapira, Michal

2016-01-01

Microalgae comprise a biodiverse group of photosynthetic organisms that reside in water sources and sediments. The green microalgae Chlamydomonas reinhardtii was adopted as a useful model organism for studying various physiological systems. Its ability to grow under both photosynthetic and heterotrophic conditions allows efficient growth of non-photosynthetic mutants, making Chlamydomonas a useful genetic tool to study photosynthesis. In addition, this green alga can grow as haploid or diploid cells, similar to yeast, providing a powerful genetic system. As a result, easy and efficient transformation systems have been developed for Chlamydomonas, targeting both the chloroplast and nuclear genomes. Since microalgae comprise a rich repertoire of species that offer variable advantages for biotech and biomed industries, gene transfer technologies were further developed for many microalgae to allow for the expression of foreign proteins of interest. Expressing foreign genes in the chloroplast enables the targeting of foreign DNA to specific sites by homologous recombination. Chloroplast transformation also allows for the introduction of genes encoding several enzymes from a complex pathway, possibly as an operon. Expressing foreign proteins in the chloroplast can also be achieved by introducing the target gene into the nuclear genome, with the protein product bearing a targeting signal that directs import of the transgene-product into the chloroplast, like other endogenous chloroplast proteins. Integration of foreign genes into the nuclear genome is mostly random, resulting in large variability between different clones, such that extensive screening is required. The use of different selection modalities is also described, with special emphasis on the use of herbicides and metabolic markers which are considered to be friendly to the environment, as compared to drug-resistance genes that are commonly used. Finally, despite the development of a wide range of transformation

Experiencia en reconstrucción de tercio distal de pierna con colgajo libre de músculo gracilis

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A. Conejero

2013-09-01

Full Text Available En los defectos de cobertura distales de la pierna con exposición ósea o articular, la transferencia de tejidos libres es frecuentemente la única opción viable. Se utilizan en el rescate de extremidades inferiores en riesgo por trauma, infección, ulceración, quemaduras y tumores. El colgajo libre de músculo gracilis está descrito en la literatura como una excelente alternativa. El objetivo de este estudio es describir las características de los pacientes y resultados de la utilización del colgajo libre de músculo gracilis en la reconstrucción del tercio distal de la pierna. Se trata de un estudio retrospectivo, observacional, de revisión de archivo clínico y fotográfico de 7 pacientes operados por los autores entre los años 2007-2010, 4 hombres y 3 mujeres con un promedio de edad de 38,5 años. El defecto de cobertura que motivó la cirugía (de hasta de 20 x 6 cm fue secundario a fractura expuesta (tipo III de Gustilo y a osteomielitis crónica. La cobertura del colgajo se hizo en todos los casos con injerto dermo-epidérmico. No hubo complicaciones menores ni mayores del sitio donante ni del receptor, con resultados funcionales y estéticos satisfactorios. El colgajo libre de músculo gracilis es una muy buena alternativa para la reconstrucción distal de pierna con defectos de cobertura en fracturas expuestas y osteomielitis o en úlceras crónicas. Tras el seguimiento, todos nuestros pacientes lograron una cobertura completa y estable en el tiempo.

A Method for Microalgae Proteomics Analysis Based on Modified Filter-Aided Sample Preparation.

Science.gov (United States)

Li, Song; Cao, Xupeng; Wang, Yan; Zhu, Zhen; Zhang, Haowei; Xue, Song; Tian, Jing

2017-11-01

With the fast development of microalgal biofuel researches, the proteomics studies of microalgae increased quickly. A filter-aided sample preparation (FASP) method is widely used proteomics sample preparation method since 2009. Here, a method of microalgae proteomics analysis based on modified filter-aided sample preparation (mFASP) was described to meet the characteristics of microalgae cells and eliminate the error caused by over-alkylation. Using Chlamydomonas reinhardtii as the model, the prepared sample was tested by standard LC-MS/MS and compared with the previous reports. The results showed mFASP is suitable for most of occasions of microalgae proteomics studies.

Economics of microalgae production

NARCIS (Netherlands)

Acién, F.G.; Molina, E.; Fernández-Sevilla, J.M.; Barbosa, M.; Gouveia, L.; Sepúlveda, C.; Bazaes, J.; Arbib, Z.

2017-01-01

The economic analysis of biomass production is a critical step in ensuring the success of any microalgae-based industry. Until recently, only small-scale facilities of less than 10. ha have been in operation, but now large-scale facilities of more than 200. ha are being built and operated.

Lichen microalgae are sensitive to environmental concentrations of atrazine.

Science.gov (United States)

Traba, Helena Moreno; Domínguez-Morueco, Noelia; Barreno, Eva; Catalá, Myriam

2017-04-03

The identification of new organisms for environmental toxicology bioassays is currently a priority, since these tools are strongly limited by the ecological relevance of taxa used to study global change. Lichens are sensitive bioindicators of air quality and their microalgae are an untapped source for new low-cost miniaturized bioassays with ecological importance. In order to increase the availability of a wider range of taxa for bioassays, the sensitivity of two symbiotic lichen microalgae, Asterochloris erici and Trebouxia sp. TR9, to atrazine was evaluated. To achieve this goal, axenic cultures of these phycobionts in suspension were exposed to a range of environmental concentrations of the herbicide atrazine, a common water pollutant. Optical density and chlorophyll autofluorescence were used as endpoints of ecotoxicity and ecophysiology on cell suspensions. Results show that lichen microalgae show high sensitivity to very low doses of atrazine, being higher in Asterochloris erici than in Trebouxia sp. TR9. We conclude that environmental concentrations of atrazine could modify population dynamics probably through a shift in reproduction strategies of these organisms. This seminal work is a breakthrough in the use of lichen microalgae in the assessment of micropollution effects on biodiversity.

Thermogravimetric analysis of co-combustion between microalgae and textile dyeing sludge.

Science.gov (United States)

Peng, Xiaowei; Ma, Xiaoqian; Xu, Zhibin

2015-03-01

The synergistic interaction and kinetics of microalgae, textile dyeing sludge and their blends were investigated under combustion condition by thermogravimetric analysis. The textile dyeing sludge was blended with microalgae in the range of 10-90wt.% to investigate their co-combustion behavior. Results showed that the synergistic interaction between microalgae and textile dyeing sludge improved the char catalytic effect and alkali metals melt-induced effect on the decomposition of textile dyeing sludge residue at high temperature of 530-800°C. As the heating rate increasing, the entire combustion process was delayed but the combustion intensity was enhanced. The lowest average activation energy was obtained when the percentage of microalgae was 60%, which was 227.1kJ/mol by OFW and 227.4kJ/mol by KAS, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Water use and its recycling in microalgae cultivation for biofuel application.

Science.gov (United States)

Farooq, Wasif; Suh, William I; Park, Min S; Yang, Ji-Won

2015-05-01

Microalgal biofuels are not yet economically viable due to high material and energy costs associated with production process. Microalgae cultivation is a water-intensive process compared to other downstream processes for biodiesel production. Various studies found that the production of 1 L of microalgal biodiesel requires approximately 3000 L of water. Water recycling in microalgae cultivation is desirable not only to reduce the water demand, but it also improves the economic feasibility of algal biofuels as due to nutrients and energy savings. This review highlights recently published studies on microalgae water demand and water recycling in microalgae cultivation. Strategies to reduce water footprint for microalgal cultivation, advantages and disadvantages of water recycling, and approaches to mitigate the negative effects of water reuse within the context of water and energy saving are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Energy from biomass production - photosynthesis of microalgae?

Energy Technology Data Exchange (ETDEWEB)

Lamparter, Tilman [Universitaet Karlsruhe, Botanisches Institut, Geb. 10.40, Kaiserstr. 2, D-76131 Karlsruhe (Germany)

2009-07-01

The composition of our atmosphere in the past, present and future is largely determined by photosynthetic activity. Other biological processes such as respiration consume oxygen and produce, like the use of the limited fossil fuel resources, CO{sub 2} whose increasing atmospheric concentration is a major concern. There is thus a demand on the development of alternative energy sources that replace fossil fuel. The use of crop plants for the production of biofuel is one step towards this direction. Since most often the same areas are used as for the production of food, the increased production of biofuel imposes secondary problems, however. In this context, the use of microalgae for biomass production has been proposed. Not only algae in the botanical sense (lower plants, photosynthetic eukaryotes) but also cyanobacteria, which belong to the prokaryotes, are used as ''microalgae''. The conversion of light energy into biomass can reach much higher efficiencies than in crop plants, in which a great portion of photosynthesis products is used to build up non-photosynthetic tissues such as roots or stems. Microalgae can grow in open ponds or bioreactors and can live on water of varying salinity. It has been proposed to grow microalgae in sea water on desert areas. Ongoing research projects aim at optimizing growth conditions in bioreactors, the recycling of CO{sub 2} from flue gases (e.g. from coal-fired power plants), the production of hydrogen, ethanol or lipids, and the production of valuable other substances such as carotenoids.

Investigation of microalgae with photon density waves

Science.gov (United States)

Frankovitch, Christine; Reich, Oliver; Löhmannsröben, Hans-Gerd

2007-09-01

Phototropic microalgae have a large potential for producing valuable substances for the feed, food, cosmetics, pigment, bioremediation, and pharmacy industries as well as for biotechnological processes. Today it is estimated that the microalgal aquaculture worldwide production is 5000 tons of dry matter per year (not taking into account processed products) making it an approximately $1.25 billion U.S. per year industry. For effective observation of the photosynthetic growth processes, fast on-line sensor systems that analyze the relevant biological and technical process parameters are preferred. The optical properties of the microalgae culture influence the transport of light in the photobioreactor and can be used to extract relevant information for efficient cultivation practices. Microalgae cultivation media show a combination of light absorption and scattering, which are influenced by the concentrations and the physical and chemical properties of the different absorbing and scattering species (e.g. pigments, cell components, etc.). Investigations with frequency domain photon density waves (PDW) allow for the examination of absorption and scattering properties of turbid media, namely the absorption and reduced scattering coefficient. The reduced scattering coefficient can be used to characterize physical and morphological properties of the medium, including the cell concentration, whereas the absorption coefficient correlates with the pigment content. Nannochloropsis oculata, a single-cell species of microalgae, were examined in a nutrient solution with photon density waves. The absorption and reduced scattering coefficients were experimentally determined throughout the cultivation process, and applied to gain information about the cell concentration and average cell radius.

Biodiesel from wet microalgae: extraction with hexane after the microwave-assisted transesterification of lipids.

Science.gov (United States)

Cheng, Jun; Huang, Rui; Li, Tao; Zhou, Junhu; Cen, Kefa

2014-10-01

A chloroform-free novel process for the efficient production of biodiesel from wet microalgae is proposed. Crude biodiesel is produced through extraction with hexane after microwave-assisted transesterification (EHMT) of lipids in wet microalgae. Effects of different parameters, including reaction temperature, reaction time, methanol dosage, and catalyst dosage, on fatty acids methyl esters (FAMEs) yield are investigated. The yield of FAME extracted into the hexane from the wet microalgae is increased 6-fold after the transesterification of lipids. The yield of FAME obtained through EHMT of lipids in wet microalgae is comparable to that obtained through direct transesterification of dried microalgae biomass with chloroform; however, FAME content in crude biodiesel obtained through EHMT is 86.74%, while that in crude biodiesel obtained through the chloroform-based process is 75.93%. EHMT ensures that polar pigments present in microalgae are not extracted into crude biodiesel, which leads to a 50% reduction in nitrogen content in crude biodiesel. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fuels from microalgae: Technology status, potential, and research requirements

Energy Technology Data Exchange (ETDEWEB)

Neenan, B.; Feinberg, D.; Hill, A.; McIntosh, R.; Terry, K.

1986-08-01

Although numerous options for the production of fuels from microalgae have been proposed, our analysis indicates that only two qualify for extensive development - gasoline and ester fuel. In developing the comparisons that support this conclusion, we have identified the major areas of microalgae production and processing that require extensive development. Technology success requires developing and testing processes that fully utilize the polar and nonpolar lipids produced by microalgae. Process designs used in these analyses were derived from fragmented, preliminary laboratory data. These results must be substantiated and integrated processes proposed, tested, and refined to be able to evaluate the commercial feasibility from microalgae. The production of algal feedstocks for processing to gasoline or ester fuel requires algae of high productivity and high lipid content that efficiently utilize saline waters. Species screening and development suggest that algae can achieve required standards taken individually, but algae that can meet the integrated requirements still elude researchers. Effective development of fuels from microalgae technology requires that R and D be directed toward meeting the integrated standards set out in the analysis. As technology analysts, it is inappropriate for us to dictate how the R and D effort should proceed to meet these standards. We end our role by noting that alternative approaches to meeting the feasibility targets have been identified, and it is now the task of program managers and scientists to choose the appropriate approach to assure the greatest likelihood of realizing a commercially viable technology. 70 refs., 39 figs., 35 tabs.

High Lipid Induction in Microalgae for Biodiesel Production

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Peer M. Schenk

2012-05-01

Full Text Available Oil-accumulating microalgae have the potential to enable large-scale biodiesel production without competing for arable land or biodiverse natural landscapes. High lipid productivity of dominant, fast-growing algae is a major prerequisite for commercial production of microalgal oil-derived biodiesel. However, under optimal growth conditions, large amounts of algal biomass are produced, but with relatively low lipid contents, while species with high lipid contents are typically slow growing. Major advances in this area can be made through the induction of lipid biosynthesis, e.g., by environmental stresses. Lipids, in the form of triacylglycerides typically provide a storage function in the cell that enables microalgae to endure adverse environmental conditions. Essentially algal biomass and triacylglycerides compete for photosynthetic assimilate and a reprogramming of physiological pathways is required to stimulate lipid biosynthesis. There has been a wide range of studies carried out to identify and develop efficient lipid induction techniques in microalgae such as nutrients stress (e.g., nitrogen and/or phosphorus starvation, osmotic stress, radiation, pH, temperature, heavy metals and other chemicals. In addition, several genetic strategies for increased triacylglycerides production and inducibility are currently being developed. In this review, we discuss the potential of lipid induction techniques in microalgae and also their application at commercial scale for the production of biodiesel.

Ingestion of Brachionus plicatilis under different microalgae conditions

Science.gov (United States)

Zhou, Wenli; Tang, Xuexi; Qiao, Xiuting; Wang, You; Wang, Renjun; Feng, Lei

2009-09-01

The effects of four microalgae, Chlorella vulgaris, Platymonas helgolandicavar, Isochrysis galbana, and Nitzschia closterium on the grazing and filtering rates of the marine rotifer, Brachionus plicatilis, were evaluated under laboratory conditions. The grazing rates in separate cultures of the four microalga were as follows: C. vulgaris > P. helgolandicavar > I. galbana > N. closterium. However, the filtering rates occurred in the following order: P. helgolandicavar > N. closterium > C. vulgaris > I. galbana. A mixed diets experiment revealed that P. helgolandicavar was the preferred diet of B. plicatilis. In addition, the grazing rate of B. plicatilis increased gradually as the density of the microalgae increased, until concentrations of 2.5×106 cells mL-1 for C. vulgaris and 1.5×106 cells mL-1 for I. galbana were obtained. Furthermore, the filtering rate increased slightly when the density of the microalgae was low, after which it declined as the microalgal density increased. The grazing rates of B. plicatilis were as follows during the different growth phases: stationary phase > exponential phase > lag phase > decline phase. Additionally, the filtering rates during the growth phases were: exponential phase > lag phase > stationary phase > decline phase. The results of this study provide foundational information that can be used to explore the optimal culture conditions for rotifers and to promote the development of aquaculture.

Scale-up and large-scale production of Tetraselmis sp. CTP4 (Chlorophyta) for CO2 mitigation: from an agar plate to 100-m3 industrial photobioreactors.

Science.gov (United States)

Pereira, Hugo; Páramo, Jaime; Silva, Joana; Marques, Ana; Barros, Ana; Maurício, Dinis; Santos, Tamára; Schulze, Peter; Barros, Raúl; Gouveia, Luísa; Barreira, Luísa; Varela, João

2018-03-23

Industrial production of novel microalgal isolates is key to improving the current portfolio of available strains that are able to grow in large-scale production systems for different biotechnological applications, including carbon mitigation. In this context, Tetraselmis sp. CTP4 was successfully scaled up from an agar plate to 35- and 100-m 3 industrial scale tubular photobioreactors (PBR). Growth was performed semi-continuously for 60 days in the autumn-winter season (17 th October - 14 th December). Optimisation of tubular PBR operations showed that improved productivities were obtained at a culture velocity of 0.65-1.35 m s -1 and a pH set-point for CO 2 injection of 8.0. Highest volumetric (0.08 ± 0.01 g L -1 d -1 ) and areal (20.3 ± 3.2 g m -2 d -1 ) biomass productivities were attained in the 100-m 3 PBR compared to those of the 35-m 3 PBR (0.05 ± 0.02 g L -1 d -1 and 13.5 ± 4.3 g m -2 d -1 , respectively). Lipid contents were similar in both PBRs (9-10% of ash free dry weight). CO 2 sequestration was followed in the 100-m 3 PBR, revealing a mean CO 2 mitigation efficiency of 65% and a biomass to carbon ratio of 1.80. Tetraselmis sp. CTP4 is thus a robust candidate for industrial-scale production with promising biomass productivities and photosynthetic efficiencies up to 3.5% of total solar irradiance.

Interacción bacteria-microalga en el ambiente marino y uso potencial en acuicultura Microalgae and bacteria interaction in the aquatic environment and their potential use in aquaculture

Directory of Open Access Journals (Sweden)

CARLOS E. RIQUELME

2003-12-01

Full Text Available El presente estudio tiene como objetivo revisar el conocimiento generado sobre el rol que juegan las interacciones bacteria-microalga en ambientes marinos y dulceacuícolas, definiendo las posibles aplicaciones que puede tener el conocimiento de estas interacciones en el manejo de las aguas costeras y sistemas acuícolas. Los antecedentes proporcionados en este análisis permiten sugerir que bacterias y/o microalgas, constituyen una alternativa para el control de proliferaciones de bacterias y fitoplancton causantes de efectos dañinos en ambientes naturales y sistemas cerrados de cultivo. Además, las interacciones específicas entre bacteria-microalga permitiría la optimización de sistemas productivos en la industria acuícola. Sin embargo, los mecanismos de estas interacciones son pobremente entendidos. Futuras investigaciones debieran ser dirigidas a comprender el modo de acción de las interacciones bacteria-microalga a nivel molecularThe objective of this survey is to review the knowledge generated with respect to the role of bacteria-microalgae interaction play in marine and fresh environments, and to define the possible application of these microorganisms on the management of costal water and aquaculture systems. This review proposes that bacteria and/or microalgae are an alternative to control the proliferation of bacteria and phytoplankton that cause damages in natural environments or in closed culture systems. Also, the knowledge of specific interactions between bacteria and microalgae will allow the optimization of productive systems in aquaculture. However, until date the mechanisms involved in these interactions are poorly understood. Therefore, future investigations should be directed towards understanding the mode of action of such interactions at a molecular level

Biodiesel renovável derivado de microalgas: avanços e perspectivas tecnológicas

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Claudio M. P. Pereira

2012-01-01

Full Text Available Microalgae are a promising source of raw material for biodiesel production. This review discusses the latest developments related to the application of microalgae biomass for biodiesel production. Characterization of fatty acid of microalgae and comparisons with other sources of raw materials and processes are presented. Furthermore, technological perspectives and approaches for growing microalgae in photobioreactors, microalgal oil extraction techniques, and procedures for synthesizing biodiesel are reviewed.

Biodiesel de microalgas: avanços e desafios

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André Luiz Custódio Franco

2013-01-01

Full Text Available Microalgae biomass has been described by several authors as the raw material with the greatest potential to meet the goals of replacing petroleum diesel by biodiesel while not competing with arable land suitable for food production. Research groups in different countries are seeking the most appropriate production model for productivity, economic viability and environmental sustainability. This review focused on recent advances and challenges of technology for the production of biodiesel from microalgae, including the procedures used to obtain biomass.

Chemical composition of microalgae Heterochlorella luteoviridis and Dunaliella tertiolecta with emphasis on carotenoids.

Science.gov (United States)

Diprat, Andressa Bacalau; Menegol, Tania; Boelter, Juliana Ferreira; Zmozinski, Ariane; Rodrigues Vale, Maria Goreti; Rodrigues, Eliseu; Rech, Rosane

2017-08-01

Microalgae have been used as food supplements owing to their high protein, polyunsaturated fatty acid and carotenoid contents. As different carotenoids have distinct properties and the carotenoid composition of microalgae has been poorly explored in the literature, this study determined the complete carotenoid composition of two microalgae species, Heterochlorella luteoviridis and Dunaliella tertiolecta, using high-performance liquid chromatography coupled with diode array detection and tandem mass spectrometry (HPLC-DAD/MS 2 ). Additionally, the proximate composition and major minerals were evaluated. The carotenoid composition of the two microalgae was similar, with 13 carotenoids being found in H. luteoviridis and 12 in D. tertiolecta. The major carotenoids were all-trans-lutein (1.18 mg g -1 in H. luteoviridis and 1.59 mg g -1 in D. tertiolecta), all-trans-violaxanthin (0.52 mg g -1 in H. luteoviridis and 0.45 mg g -1 in D. tertiolecta) and all-trans-β-carotene (0.50 mg g -1 in H. luteoviridis and 0.62 mg g -1 in D. tertiolecta). All-trans-lutein was the predominant carotenoid in both microalgae, representing around 40% (mass fraction) of the total carotenoids. The lutein content found in these microalgae was significantly higher (2-40 times) than that in other important food sources of lutein (e.g. parsley, carrot, red pepper and broccoli). The microalgae H. luteoviridis and D. tertiolecta are excellent sources of lutein that could be commercially exploited by the food and pharmaceutical industries. Moreover, it was confirmed that both microalgae are good sources of protein, lipids and calcium. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Protein N-glycosylation in eukaryotic microalgae and its impact on the production of nuclear expressed biopharmaceuticals

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Elodie eMathieu-Rivet

2014-07-01

Full Text Available Microalgae are currently used for the production of food compounds. Recently, few microalgae species have been investigated as potential biofactories for the production of biopharmaceuticals. Indeed in this context, microalgae are cheap, classified as Generally Recognized As Safe (GRAS organisms and can be grown easily. However, problems remain to be solved before any industrial production of microalgae-made biopharmaceuticals. Among them, post-translational modifications of the proteins need to be considered. Especially, N-glycosylation acquired by the secreted recombinant proteins is of major concern since most of the biopharmaceuticals are N-glycosylated and it is well recognized that glycosylation represent one of their critical quality attribute. Therefore, the evaluation of microalgae as alternative cell factory for biopharmaceutical productions thus requires to investigate their N-glycosylation capability in order to determine to what extend it differs from their human counterpart and to determine appropriate strategies for remodelling the microalgae glycosylation into human-compatible oligosaccharides. Here, we review the secreted recombinant proteins which have been successfully produced in microalgae. We also report on recent bioinformatics and biochemical data concerning the structure of glycans N-linked to proteins from various microalgae phyla and comment the consequences on the glycan engineering strategies that may be necessary to render those microalgae-made biopharmaceuticals compatible with human therapy.

Sorting cells of the microalga Chlorococcum littorale with increased triacylglycerol productivity

NARCIS (Netherlands)

Dominguez Teles, I.; Zwart, van der Mathijs; Kleinegris, D.M.M.; Wijffels, R.H.; Barbosa, M.J.

2016-01-01

Despite extensive research in the last decades, microalgae are still only economically feasible for high valued markets. Strain improvement is a strategy to increase productivities, hence reducing costs. In this work, we focus on microalgae selection: taking advantage of the natural biological

Biogas Production From Cassava Starch Effluent Using Microalgae As Biostabilisator

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B. Budiyono

2011-07-01

Full Text Available The rapid growing of Indonesian population is emerging several critical national issues i.e. energy, food, environmental, water, transportation, as well as law and human right. As an agricultural country, Indonesia has abundant of biomass wastes such as agricultural wastes include the cassava starch wastes. The problem is that the effluent from cassava starch factories is released directly into the river before properly treatment. It has been a great source of pollution and has caused environmental problems to the nearby rural population. The possible alternative to solve the problem is by converting waste to energy biogas in the biodigester. The main problem of the biogas production of cassava starch effluent is acid forming-bacteria quickly produced acid resulting significantly in declining pH below the neutral pH and diminishing growth of methane bacteria. Hence, the only one of the method to cover this problem is by adding microalgae as biostabilisator of pH. Microalgae can also be used as purifier agent to absorb CO2.The general objective of this research project was to develop an integrated process of biogas production and purification from cassava starch effluent by using biostabilisator agent microalgae. This study has been focused on the used of urea, ruminant, yeast, microalgae, the treatment of gelled and ungelled feed for biogas production, pH control during biogas production using buffer Na2CO3, and feeding management in the semi-continuous process of biogas production. The result can be concluded as follows: i The biogas production increased after cassava starch effluent and yeast was added, ii Biogas production with microalgae and cassava starch effluent, yeast, ruminant bacteria, and urea were 726.43 ml/g total solid, iii Biogas production without  microalgae was 189 ml/g total solid.

Vibrating membrane filtration as improved technology for microalgae dewatering

OpenAIRE

Nurra, C.; Clavero, E.; Salvadó, J.; Torras, C.

2014-01-01

10.1016/j.biortech.2014.01.115 The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean ...

Enhanced Productivity of a Lutein-Enriched Novel Acidophile Microalga Grown on Urea

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Carlos Vilchez

2010-12-01

Full Text Available Coccomyxa acidophila is an extremophile eukaryotic microalga isolated from the Tinto River mining area in Huelva, Spain. Coccomyxa acidophila accumulates relevant amounts of b-carotene and lutein, well-known carotenoids with many biotechnological applications, especially in food and health-related industries. The acidic culture medium (pH < 2.5 that prevents outdoor cultivation from non-desired microorganism growth is one of the main advantages of acidophile microalgae production. Conversely, acidophile microalgae growth rates are usually very low compared to common microalgae growth rates. In this work, we show that mixotrophic cultivation on urea efficiently enhances growth and productivity of an acidophile microalga up to typical values for common microalgae, therefore approaching acidophile algal production towards suitable conditions for feasible outdoor production. Algal productivity and potential for carotenoid accumulation were analyzed as a function of the nitrogen source supplied. Several nitrogen conditions were assayed: nitrogen starvation, nitrate and/or nitrite, ammonia and urea. Among them, urea clearly led to the best cell growth (~4 ´ 108 cells/mL at the end of log phase. Ammonium led to the maximum chlorophyll and carotenoid content per volume unit (220 mg·mL-1 and 35 mg·mL-1, respectively. Interestingly, no significant differences in growth rates were found in cultures grown on urea as C and N source, with respect to those cultures grown on nitrate and CO2 as nitrogen and carbon sources (control cultures. Lutein accumulated up to 3.55 mg·g-1 in the mixotrophic cultures grown on urea. In addition, algal growth in a shaded culture revealed the first evidence for an active xanthophylls cycle operative in acidophile microalgae.

Cell disruption for microalgae biorefineries

NARCIS (Netherlands)

Günerken, E.; Hondt, d' E.; Eppink, M.H.M.; Garcia-Gonzalez, L.; Elst, K.; Wijffels, R.H.

2015-01-01

Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of

Techno-economical evaluation of protein extraction for microalgae biorefinery

Science.gov (United States)

Sari, Y. W.; Sanders, J. P. M.; Bruins, M. E.

2016-01-01

Due to scarcity of fossil feedstocks, there is an increasing demand for biobased fuels. Microalgae are considered as promising biobased feedstocks. However, microalgae based fuels are not yet produced at large scale at present. Applying biorefinery, not only for oil, but also for other components, such as carbohydrates and protein, may lead to the sustainable and economical microalgae-based fuels. This paper discusses two relatively mild conditions for microalgal protein extraction, based on alkali and enzymes. Green microalgae (Chlorella fusca) with and without prior lipid removal were used as feedstocks. Under mild conditions, more protein could be extracted using proteases, with the highest yields for microalgae meal (without lipids). The data on protein extraction yields were used to calculate the costs for producing 1 ton of microalgal protein. The processing cost for the alkaline method was € 2448 /ton protein. Enzymatic method performed better from an economic point of view with € 1367 /ton protein on processing costs. However, this is still far from industrially feasible. For both extraction methods, biomass cost per ton of produced product were high. A higher protein extraction yield can partially solve this problem, lowering processing cost to €620 and 1180 /ton protein product, using alkali and enzyme, respectively. Although alkaline method has lower processing cost, optimization appears to be better achievable using enzymes. If the enzymatic method can be optimized by lowering the amount of alkali added, leading to processing cost of € 633/ton protein product. Higher revenue can be generated when the residue after protein extraction can be sold as fuel, or better as a highly digestible feed for cattle.

Microalgae Harvest through Fungal Pelletization—Co-Culture of Chlorella vulgaris and Aspergillus niger

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Sarman Oktovianus Gultom

2014-07-01

Full Text Available Microalgae harvesting is a labor- and energy-intensive process and new approaches to harvesting microalgae need to be developed in order to decrease the costs. In this study; co-cultivatation of filamentous fungus (Aspergillus niger and microalgae (Chlorella vulgaris to form cell pellets was evaluated under different conditions, including organic carbon source (glucose; glycerol; and sodium acetate concentration; initial concentration of fungal spores and microalgal cells and light. Results showed that 2 g/L of glucose with a 1:300 ratio of fungi to microalgae provided the best culturing conditions for the process to reach >90% of cell harvest efficiency. The results also showed that an organic carbon source was required to sustain the growth of fungi and form the cell pellets. The microalgae/fungi co-cultures at mixotrophic conditions obtained much higher total biomass than pure cultures of each individual strains; indicating the symbiotic relationship between two strains. This can benefit the microbial biofuel production in terms of cell harvest and biomass production.

Paper-based device for separation and cultivation of single microalga.

Science.gov (United States)

Chen, Chih-Chung; Liu, Yi-Ju; Yao, Da-Jeng

2015-12-01

Single-cell separation is among the most useful techniques in biochemical research, diagnosis and various industrial applications. Microalgae species have great economic importance as industrial raw materials. Microalgae species collected from environment are typically a mixed and heterogeneous population of species that must be isolated and purified for examination and further application. Conventional methods, such as serial dilution and a streaking-plate method, are intensive of labor and inefficient. We developed a paper-based device for separation and cultivation of single microalga. The fabrication was simply conducted with a common laser printer and required only a few minutes without lithographic instruments and clean-room. The driving force of the paper device was simple capillarity without a complicated pump connection that is part of most devices for microfluidics. The open-structure design of the paper device makes it operable with a common laboratory micropipette for sample transfer and manipulation with a naked eye or adaptable to a robotic system with functionality of high-throughput retrieval and analysis. The efficiency of isolating a single cell from mixed microalgae species is seven times as great as with a conventional method involving serial dilution. The paper device can serve also as an incubator for microalgae growth on simply rinsing the paper with a growth medium. Many applications such as highly expressed cell selection and various single-cell analysis would be applicable. Copyright © 2015 Elsevier B.V. All rights reserved.

A study on growth and pyrolysis characteristics of microalgae using Thermogravimetric Analysis-Infrared Spectroscopy and synchrotron Fourier Transform Infrared Spectroscopy.

Science.gov (United States)

Li, Fanghua; Srivatsa, Srikanth Chakravartula; Batchelor, Warren; Bhattacharya, Sankar

2017-04-01

This two-part study firstly investigated Tetraselmis suecica grown in different CO 2 (0.04-15%v/v) concentration through indoor and outdoor cultivation systems. A high CO 2 concentration led to a high lipid content, and low nitrogen and oxygen content, which are desirable for transport fuel production. Pyrolysis characteristics were investigated by TG-IR and synchrotron IR microscopy. The results show Tetraselmis suecica grown in 10%CO 2 had the highest decomposition rate corresponding to more volatile products produced during the main thermal cracking stage and derived from protein-and lipid-corresponding functional groups. Moreover, a high reaction temperature and CO 2 concentration resulted in a low retention of surface functional groups. The nitrogen functional groups initially decomposed at a temperature range of 250-300°C and still remained at 550°C, while the lipid-corresponding functional groups completely disappeared at a temperature range of 400-500°C. Besides, the decomposition of chemical components followed the order of carbohydrate, protein and lipid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simulation of temperature effect on microalgae culture in a tubular photo bioreactor for local solar irradiance

Science.gov (United States)

Shahriar, M.; Deb, Ujjwal Kumar; Rahman, Kazi Afzalur

2017-06-01

Microalgae based biofuel is now an emerging source of renewable energy alternative to the fossil fuel. This paper aims to present computational model of microalgae culture taking effect of solar irradiance and corresponding temperature in a photo bioreactor (PBR). As microalgae is a photosynthetic microorganism, so irradiance of sunlight is one of the important limiting factors for the proper growth of microalgae cells as temperature is associated with it. We consider the transient behaviour of temperature inside the photo bioreactor for a microalgae culture. The optimum range of temperature for outdoor cultivation of microalgae is about 16-35°c and out of this range the cell growth inhibits. Many correlations have already been established to investigate the heat transfer phenomena inside a tubular PBR. However, none of them are validated yet numerically by using a user defined function in a simulated model. A horizontal tubular PBR length 20.5m with radius 0.05m has taken account to investigate the temperature effect for the growth of microalgae cell. As the solar irradiance varies at any geographic latitude for a year so an empirical relation is established between local solar irradiance and temperature to simulate the effect. From our simulation, we observed that the growth of microalgae has a significant effect of temperature and the solar irradiance of our locality is suitable for the culture of microalgae.

A Holistic Approach to Managing Microalgae for Biofuel Applications

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Pau Loke Show

2017-01-01

Full Text Available Microalgae contribute up to 60% of the oxygen content in the Earth’s atmosphere by absorbing carbon dioxide and releasing oxygen during photosynthesis. Microalgae are abundantly available in the natural environment, thanks to their ability to survive and grow rapidly under harsh and inhospitable conditions. Microalgal cultivation is environmentally friendly because the microalgal biomass can be utilized for the productions of biofuels, food and feed supplements, pharmaceuticals, nutraceuticals, and cosmetics. The cultivation of microalgal also can complement approaches like carbon dioxide sequestration and bioremediation of wastewaters, thereby addressing the serious environmental concerns. This review focuses on the factors affecting microalgal cultures, techniques adapted to obtain high-density microalgal cultures in photobioreactors, and the conversion of microalgal biomass into biofuels. The applications of microalgae in carbon dioxide sequestration and phycoremediation of wastewater are also discussed.

Microalga propels along vorticity direction in a shear flow

Science.gov (United States)

Chengala, Anwar; Hondzo, Miki; Sheng, Jian

2013-05-01

Using high-speed digital holographic microscopy and microfluidics, we discover that, when encountering fluid flow shear above a threshold, unicellular green alga Dunaliella primolecta migrates unambiguously in the cross-stream direction that is normal to the plane of shear and coincides with the local fluid flow vorticity. The flow shear drives motile microalgae to collectively migrate in a thin two-dimensional horizontal plane and consequently alters the spatial distribution of microalgal cells within a given suspension. This shear-induced algal migration differs substantially from periodic rotational motion of passive ellipsoids, known as Jeffery orbits, as well as gyrotaxis by bottom-heavy swimming microalgae in a shear flow due to the subtle interplay between torques generated by gravity and viscous shear. Our findings could facilitate mechanistic solutions for modeling planktonic thin layers and sustainable cultivation of microalgae for human nutrition and bioenergy feedstock.

Ultrasonic assisted biodiesel production of microalgae by direct transesterification

Science.gov (United States)

Kalsum, Ummu; Mahfud, Mahfud; Roesyadi, Achmad

2017-03-01

Microalgae are considered as the third generation source of biofuel and an excellent candidate for biofuel production to replace the fossil energy. The use of ultrasonic in producing biodiesel by direct transesterification of Nannochloropsis occulata using KOH as catalyst and methanol as a solvent was investigated. The following condition were determined as an optimum by experimental evaluates:: 1: 15 microalga to methanol (molar ratio); 3% catalyst concentration at temperature 40°C after 30 minute of ultrasonication. The highest yield of biodiesel produced was 30.3%. The main components of methyl ester from Nannochloropsis occulata were palmitic (C16 :0),, oleic (C18:1), stearic (C18;0), arahidic (C20:0) and myristic (C14:0). This stated that the application of ultrasounic for direct transesterificaiton of microalgae effectively reduced the reaction time compared to the reported values of conventional heating systems.

Mild disintegration of the green microalgae Chlorella vulgaris using bead milling

NARCIS (Netherlands)

Postma, P.R.; Miron, T.L.; Olivieri, G.; Barbosa, M.J.; Wijffels, R.H.; Eppink, M.H.M.

2015-01-01

In this work, the mild disintegration of the microalgae Chlorella vulgaris for the release of intracellular products has been studied. By means of bead milling the microalgae suspensions were successfully disintegrated at different biomass concentrations (25–145 gDW kg-1) over a range of agitator

Lipid-based liquid biofuels from autotrophic microalgae: energetic and environmental performance

NARCIS (Netherlands)

Reijnders, L.

2013-01-01

Commercial cultivation of autotrophic microalgae for food production dates back to the 1950s. Autotrophic microalgae have also been proposed as a source for lipid-based liquid biofuels. As yet, there is no commercial production of such biofuels and estimated near-term prices are far in excess of

Chemical Profiles of Microalgae with Emphasis on Lipids: Final Report

Energy Technology Data Exchange (ETDEWEB)

Benemann, J. R.; Tillett, D. M.; Suen, Y.; Hubbard, J.; Tornabene, T. G.

1986-02-01

This final report details progress during the third year of this subcontract. The overall objective of this subcontract was two fold: to provide the analytical capability required for selecting microalgae strains with high energy contents and to develop fundamental knowledge required for optimizing the energy yield from microalgae cultures. The progress made towards these objectives during this year is detailed in this report.

Potential of Microalgae Cultivation in Dairy Wastewater as a Step in Low-Cost Biofuel Production

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Basma Abbas Abdulmajeed

2018-04-01

Full Text Available The present study addresses adopting the organic and nutritious materials in dairy wastewater as media for cultivation of microalgae, which represent an important source of renewable energy. This study was carried out through cultivation of three types of microalgae; Chlorella sp., Synechococcus, and Anabaena. The results shows the success the cultivation of the Synechococcus and Chlorella Sp, while the Anabaena microalgae were in low-growth level. The highest growth was in the Synechococcus farm, followed by Chlorella and Anabaena. However, the growth of Synechococcus required 10 days to achieve this increase that represents a negative indicator of the adoption of this type of microalgae in this media to meet the desired aims. While Chlorella needs less than two days to start growing. Moreover, the data obtained from the experiment show that removal of chemical oxygen demand in Chlorella cultures was (72% more than that obtained from cultivation of other microalgae. Thus this microalgae is more efficient in wastewater treatment than other types.

Efficient harvesting of marine Chlorella vulgaris microalgae utilizing cationic starch nanoparticles by response surface methodology.

Science.gov (United States)

Bayat Tork, Mahya; Khalilzadeh, Rasoul; Kouchakzadeh, Hasan

2017-11-01

Harvesting involves nearly thirty percent of total production cost of microalgae that needs to be done efficiently. Utilizing inexpensive and highly available biopolymer-based flocculants can be a solution for reducing the harvest costs. Herein, flocculation process of Chlorella vulgaris microalgae using cationic starch nanoparticles (CSNPs) was evaluated and optimized through the response surface methodology (RSM). pH, microalgae and CSNPs concentrations were considered as the main independent variables. Under the optimum conditions of microalgae concentration 0.75gdry weight/L, CSNPs concentration 7.1mgdry weight/L and pH 11.8, the maximum flocculation efficiency (90%) achieved. Twenty percent increase in flocculation efficiency observed with the use of CSNPs instead of the non-particulate starch which can be due to the more electrostatic interactions between the cationic nanoparticles and the microalgae. Therefore, the synthesized CSNPs can be employed as a convenient and economical flocculants for efficient harvest of Chlorella vulgaris microalgae at large scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

Marine microalgae used as food supplements and their implication in preventing cardiovascular diseases

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Mimouni Virginie

2015-07-01

Full Text Available Marine microalgae are photosynthetic microorganisms producing numerous bioactive molecules of interest for health and disease care such as lipids rich in omega-3 fatty acids -as eicosapentaenoic acid (EPA, 20:5 n-3 and docosahexaenoic acid (DHA, 22:6 n-3- and carotenoids (e.g., β-carotene, fucoxanthin, astaxanthin. It has already been shown that these molecules, individually used, are benefic in the prevention of diseases such as those associated with the cardiovascular risks, but also in some carcinomas. When these molecules are combined, synergistic effects may be observed. Microalgae, as a dietary supplement, can be used to study these synergistic effects in animal models in which dyslipidemia can be induced by a nutrition treatment. Different marine microalgae of interest are studied in this context to determine their potential effect as an alternative source to marine omega-3 rich fish oils, actually widely used for human health. Actually, the pharmaceutical and nutrition industries are developing health research programs involving microalgae, trying to limit the dramatic reduction of fish stocks and the associated pollution in the marine environment. The aim of this review is threefold: (1 to present research on lipids, particularly long chain polyunsaturated fatty acids, as components of marine microalgae used as food supplements; (2 to present the health benefits of some microalgae or their extracts, in particular in the prevention of cardiovascular diseases and (3 to highlight the role of Odontella aurita, a marine microalga rich in EPA used as food supplement with the aim of preventing cardiovascular diseases.

Use of Solid Waste from Thermoelectric Plants for the Cultivation of Microalgae

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Bruna da Silva Vaz

2016-01-01

Full Text Available ABSTRACT The aim of this study was to analyze the influence of solid waste on the cultivation of the microalgae Spirulina sp. LEB 18 and Chlorella fusca LEB 111 with 0, 40, 80 and 120 ppm of mineral coal ash. The addition of the ash did not inhibit the cultivation of microalgae at the tested concentrations, showing that it could be used for the cultivation of these microalgae due to the minerals present in the ash, which might substitute the nutrients needed for their growth.

Transgene expression in microalgae – from tools to applications

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Lior eDoron

2016-04-01

Full Text Available Microalgae comprise a biodiverse group of photosynthetic organisms that reside in water sources and sediments. The green microalgae Chlamydomonas reinhardtii was adopted as a useful model organism for studying various physiological systems. Its ability to grow under both photosynthetic and heterotrophic conditions allows efficient growth of non-photosynthetic mutants, making Chlamydomonas a useful genetic tool to study photosynthesis. In addition, this green alga can grow as haploid or diploid cells, similar to yeast, providing a powerful genetic system. As a result, easy and efficient transformation systems have been developed for Chlamydomonas, targeting both the chloroplast and nuclear genomes. Since microalgae comprise a rich repertoire of species that offer variable advantages for biotech and biomed industries, gene transfer technologies were further developed for many microalgae to allow for the expression of foreign proteins of interest. Expressing foreign genes in the chloroplast enables the targeting of foreign DNA to specific sites by homologous recombination. Chloroplast transformation also allows for the introduction of genes encoding several enzymes from a complex pathway, possibly as an operon. Expressing foreign proteins in the chloroplast can also be achieved by introducing the target gene into the nuclear genome, with the protein product bearing a targeting signal that directs import of the transgene-product into the chloroplast, like other endogenous chloroplast proteins. Integration of foreign genes into the nuclear genome is mostly random, resulting in large variability between different clones, such that extensive screening is required. The use of different selection modalities is also described, with special emphasis on the use of herbicides and metabolic markers which are considered to be friendly to the environment, as compared to drug-resistance genes that are commonly used. Finally, despite the development of a wide

Removal of metal from acid mine drainage using a hybrid system including a pipes inserted microalgae reactor.

Science.gov (United States)

Park, Young-Tae; Lee, Hongkyun; Yun, Hyun-Shik; Song, Kyung-Guen; Yeom, Sung-Ho; Choi, Jaeyoung

2013-12-01

In this study, the microalgae culture system to combined active treatment system and pipe inserted microalgae reactor (PIMR) was investigated. After pretreated AMD in active treatment system, the effluent load to PIMR in order to Nephroselmis sp. KGE 8 culture. In experiment, effect of iron on growth and lipid accumulation in microalgae were inspected. The 2nd pretreatment effluent was economic feasibility of microalgae culture and lipid accumulation. The growth kinetics of the microalgae are modeled using logistic growth model and the model is primarily parameterized from data obtained through an experimental study where PIMR were dosed with BBM, BBM added 10 mg L(-1) iron and 2nd pretreatment effluent. Moreover, the continuous of microalgae culture in PIMR can be available. Overall, this study indicated that the use of pretreated AMD is a viable method for culture microalgae and lipid accumulation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Combustion of Microalgae Oil and Ethanol Blended with Diesel Fuel

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Saddam H. Al-lwayzy

2015-12-01

Full Text Available Using renewable oxygenated fuels such as ethanol is a proposed method to reduce diesel engine emission. Ethanol has lower density, viscosity, cetane number and calorific value than petroleum diesel (PD. Microalgae oil is renewable, environmentally friendly and has the potential to replace PD. In this paper, microalgae oil (10% and ethanol (10% have been mixed and added to (80% diesel fuel as a renewable source of oxygenated fuel. The mixture of microalgae oil, ethanol and petroleum diesel (MOE20% has been found to be homogenous and stable without using surfactant. The presence of microalgae oil improved the ethanol fuel demerits such as low density and viscosity. The transesterification process was not required for oil viscosity reduction due to the presence of ethanol. The MOE20% fuel has been tested in a variable compression ratio diesel engine at different speed. The engine test results with MOE20% showed a very comparable engine performance of in-cylinder pressure, brake power, torque and brake specific fuel consumption (BSFC to that of PD. The NOx emission and HC have been improved while CO and CO2 were found to be lower than those from PD at low engine speed.

Volatile Metabolites Emission by In Vivo Microalgae-An Overlooked Opportunity?

Science.gov (United States)

Achyuthan, Komandoor E; Harper, Jason C; Manginell, Ronald P; Moorman, Matthew W

2017-07-31

Fragrances and malodors are ubiquitous in the environment, arising from natural and artificial processes, by the generation of volatile organic compounds (VOCs). Although VOCs constitute only a fraction of the metabolites produced by an organism, the detection of VOCs has a broad range of civilian, industrial, military, medical, and national security applications. The VOC metabolic profile of an organism has been referred to as its 'volatilome' (or 'volatome') and the study of volatilome/volatome is characterized as 'volatilomics', a relatively new category in the 'omics' arena. There is considerable literature on VOCs extracted destructively from microalgae for applications such as food, natural products chemistry, and biofuels. VOC emissions from living (in vivo) microalgae too are being increasingly appreciated as potential real-time indicators of the organism's state of health (SoH) along with their contributions to the environment and ecology. This review summarizes VOC emissions from in vivo microalgae; tools and techniques for the collection, storage, transport, detection, and pattern analysis of VOC emissions; linking certain VOCs to biosynthetic/metabolic pathways; and the role of VOCs in microalgae growth, infochemical activities, predator-prey interactions, and general SoH.

Techno-economic analysis of solar integrated hydrothermal liquefaction of microalgae

International Nuclear Information System (INIS)

Pearce, Matthew; Shemfe, Mobolaji; Sansom, Christopher

2016-01-01

Highlights: • Hydrothermal liquefaction and concentrated solar power provide integrated biofuel technology. • Heat kinetics and energy efficiency Aspen plus modelling of CSP and HTL. • Microalgae biofuel minimum fuel sales price of $1.23/kg. - Abstract: Integration of Hydrothermal Liquefaction (HTL) of microalgae biomass with concentrated solar power thermal processing (CSP) for bio-oil production is a potential processing pathway for energy efficient generation of renewable biofuels. Solar HTL infrastructure avoids additional bolt-on components of conventional solar parabolic trough systems used for electricity production including heat transfer fluids, counter current heat exchangers, fluid transfer interconnectivity and electrical power control systems. The absence of such capital intensive additional equipment considerably reduces the production costs of solar HTL biofuels compared to electricity generation from conventional CSP power systems. An economic and market appraisal of variance and system economic resilience is presented. It is hypothesised that the combination of nutrient recycling with HTL/CSP unification has the potential for economically sustainable microalgae bio-oil production. A microalgae biofuel minimum fuel sales price of $1.23/kg has been modelled. Further experimental work would be able to validate this integrated model.

A Label-Free Microfluidic Biosensor for Activity Detection of Single Microalgae Cells Based on Chlorophyll Fluorescence

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Junsheng Wang

2013-11-01

Full Text Available Detection of living microalgae cells is very important for ballast water treatment and analysis. Chlorophyll fluorescence is an indicator of photosynthetic activity and hence the living status of plant cells. In this paper, we developed a novel microfluidic biosensor system that can quickly and accurately detect the viability of single microalgae cells based on chlorophyll fluorescence. The system is composed of a laser diode as an excitation light source, a photodiode detector, a signal analysis circuit, and a microfluidic chip as a microalgae cell transportation platform. To demonstrate the utility of this system, six different living and dead algae samples (Karenia mikimotoi Hansen, Chlorella vulgaris, Nitzschia closterium, Platymonas subcordiformis, Pyramidomonas delicatula and Dunaliella salina were tested. The developed biosensor can distinguish clearly between the living microalgae cells and the dead microalgae cells. The smallest microalgae cells that can be detected by using this biosensor are 3 μm ones. Even smaller microalgae cells could be detected by increasing the excitation light power. The developed microfluidic biosensor has great potential for in situ ballast water analysis.

A Label-Free Microfluidic Biosensor for Activity Detection of Single Microalgae Cells Based on Chlorophyll Fluorescence

Science.gov (United States)

Wang, Junsheng; Sun, Jinyang; Song, Yongxin; Xu, Yongyi; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

2013-01-01

Detection of living microalgae cells is very important for ballast water treatment and analysis. Chlorophyll fluorescence is an indicator of photosynthetic activity and hence the living status of plant cells. In this paper, we developed a novel microfluidic biosensor system that can quickly and accurately detect the viability of single microalgae cells based on chlorophyll fluorescence. The system is composed of a laser diode as an excitation light source, a photodiode detector, a signal analysis circuit, and a microfluidic chip as a microalgae cell transportation platform. To demonstrate the utility of this system, six different living and dead algae samples (Karenia mikimotoi Hansen, Chlorella vulgaris, Nitzschia closterium, Platymonas subcordiformis, Pyramidomonas delicatula and Dunaliella salina) were tested. The developed biosensor can distinguish clearly between the living microalgae cells and the dead microalgae cells. The smallest microalgae cells that can be detected by using this biosensor are 3 μm ones. Even smaller microalgae cells could be detected by increasing the excitation light power. The developed microfluidic biosensor has great potential for in situ ballast water analysis. PMID:24287532

POSSIBILITIES OF CARBON DIOXIDE FIXATION BY MICROALGAE IN REFINERY

OpenAIRE

Šingliar, Michal; Mikulec, Jozef; Kušnir, Patrik; Polakovičova, Gabriela

2013-01-01

Capture and sequestration of carbon dioxide is one of the most critical challenges today for businesses and governments worldwide. Thousands of emitting power plants and industries worldwide face this costly challenge – reduce the CO2 emissions or pay penalties. One possibility for carbon dioxide sequestration is its fixation in microalgae. Microalgae can sequester CO2 from flue gases emitted from fossil fuel-fired refinery plants and units, thereby reducing emissions of a major greenhouse ga...

Microalgae Isolation and Selection for Prospective Biodiesel Production

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Peer M. Schenk

2012-06-01

Full Text Available Biodiesel production from microalgae is being widely developed at different scales as a potential source of renewable energy with both economic and environmental benefits. Although many microalgae species have been identified and isolated for lipid production, there is currently no consensus as to which species provide the highest productivity. Different species are expected to function best at different aquatic, geographical and climatic conditions. In addition, other value-added products are now being considered for commercial production which necessitates the selection of the most capable algae strains suitable for multiple-product algae biorefineries. Here we present and review practical issues of several simple and robust methods for microalgae isolation and selection for traits that maybe most relevant for commercial biodiesel production. A combination of conventional and modern techniques is likely to be the most efficient route from isolation to large-scale cultivation.

Heterotrophic cultivation of microalgae for pigment production: A review.

Science.gov (United States)

Hu, Jianjun; Nagarajan, Dillirani; Zhang, Quanguo; Chang, Jo-Shu; Lee, Duu-Jong

Pigments (mainly carotenoids) are important nutraceuticals known for their potent anti-oxidant activities and have been used extensively as high end health supplements. Microalgae are the most promising sources of natural carotenoids and are devoid of the toxic effects associated with synthetic derivatives. Compared to photoautotrophic cultivation, heterotrophic cultivation of microalgae in well-controlled bioreactors for pigments production has attracted much attention for commercial applications due to overcoming the difficulties associated with the supply of CO 2 and light, as well as avoiding the contamination problems and land requirements in open autotrophic culture systems. In this review, the heterotrophic metabolic potential of microalgae and their uses in pigment production are comprehensively described. Strategies to enhance pigment production under heterotrophic conditions are critically discussed and the challenges faced in heterotrophic pigment production with possible alternative solutions are presented. Copyright © 2017 Elsevier Inc. All rights reserved.

Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

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Rui Manuel Santos Costa de Morais

2013-01-01

Full Text Available Marine microalgae have been used for a long time as food for humans, such as Arthrospira (formerly, Spirulina, and for animals in aquaculture. The biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. The present review puts up-to-date the research on the biological activities and applications of polysaccharides, active biocompounds synthesized by marine unicellular algae, which are, most of the times, released into the surrounding medium (exo- or extracellular polysaccharides, EPS. It goes through the most studied activities of sulphated polysaccharides (sPS or their derivatives, but also highlights lesser known applications as hypolipidaemic or hypoglycaemic, or as biolubricant agents and drag-reducers. Therefore, the great potentials of sPS from marine microalgae to be used as nutraceuticals, therapeutic agents, cosmetics, or in other areas, such as engineering, are approached in this review.

Engineering fatty acid biosynthesis in microalgae for sustainable biodiesel.

Science.gov (United States)

Blatti, Jillian L; Michaud, Jennifer; Burkart, Michael D

2013-06-01

Microalgae are a promising feedstock for biodiesel and other liquid fuels due to their fast growth rate, high lipid yields, and ability to grow in a broad range of environments. However, many microalgae achieve maximal lipid yields only under stress conditions hindering growth and providing compositions not ideal for biofuel applications. Metabolic engineering of algal fatty acid biosynthesis promises to create strains capable of economically producing fungible and sustainable biofuels. The algal fatty acid biosynthetic pathway has been deduced by homology to bacterial and plant systems, and much of our understanding is gleaned from basic studies in these systems. However, successful engineering of lipid metabolism in algae will necessitate a thorough characterization of the algal fatty acid synthase (FAS) including protein-protein interactions and regulation. This review describes recent efforts to engineer fatty acid biosynthesis toward optimizing microalgae as a biodiesel feedstock. Copyright © 2013 Elsevier Ltd. All rights reserved.

From transient response of a compact photobioreactor for microalgae cultivation

Energy Technology Data Exchange (ETDEWEB)

Dilay, Emerson; Ribeiro, Robert Luis Lara; Pulliam, Raevon; Mariano, Andre Bellin [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Nucleo de Pesquisa e Desenvolvimento em Energia Auto-Sustentavel; Ordonez, Juan Carlos [Florida State University, Tallahassee, FL (United States). Dept. of Mechanical Engineering and Center for Advanced Power Systems], E-mail: ordonez@caps.fsu.edu; Vargas, Jose Viriato Coelho [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica

2010-07-01

Biofuels from microalgae are currently the subject of funded scientific research in many countries due to their high productivity of oil when compared with other crops. Microalgae can also be used in many important applications such as to obtain compounds of interest for food, chemicals, and pharmaceuticals. The high productivity of microalgae when compared with other crops is achieved because agricultural land is not mandatory for their cultivation, since they can be grown in open ponds, sea or vertical photo bioreactors. In this paper, a mathematical model is introduced for assessing the transient microalgae growth as a function of variable light intensity, temperature and environmental conditions in the daily cycle. Photo bioreactor geometry is considered as well. Light intensity is obtained from sun position, photo bioreactor geometry, and the installation location in the world. The photo bioreactor was discretized in space by the the volume element method. Balances of energy and species together with thermodynamics, heat transfer and chemistry empirical and theoretical correlations are applied to each volume element. Therefore, a system of ordinary differential equations with respect to time only is capable of delivering temperatures and concentrations as functions of space and time, even with a coarse mesh. The numerical results are capable of predicting the transient and steady state photo bioreactor biomass production with low computational time. Microalgae specific growth rate as a function of average light intensity inside the tubes and time was calculated. As a result, the model is expected to be a useful tool for simulation, design, and optimization of compact photo bioreactors. (author)

Pilot scale harvesting, separation and drying of microalgae biomass from compact photo-bioreactor

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Alberto Tadeu Martins; Luz Junior, Luiz Fernando de Lima [Dept. de Engenharia Quimica. Universidade Federal do Parana, Curitiba, PR (Brazil)], e-mail: luzjr@ufpr.br; Mariano, Andre Bellin; Ghidini, Luiz Francisco Correa; Gnoatto, Victor Eduardo; Locatelli Junior, Vilson; Mello, Thiago Carvalho de; Vargas, Jose Viriato Coelho [Nucleo de Pesquisa e Desenvolvimento em Energia Autossustentavel (NPDEAS). Dept. de Engenharia Mecanica. Universidade Federal do Parana, Curitiba (Brazil)], E-mail: jvargas@demec.ufpr.br

2010-07-01

Bio diesel produced from microalgae lipids is gaining a substantial ground in the search for renewable energy sources. In order to optimize the operating conditions of a continuous process, several experiments were realized, both in laboratory and pilot scale. The microalgae cultivation can be conducted in a photo-bioreactor, a closed system which allows parameters control and necessarily involves the aquatic environment. Because of that, the use of separation unit operations is required. The process starts in a proposed compact photo-bioreactor, which consist of a chain of transparent tubes with 6 cm of diameter arranged in parallel where the cultivation media circulate with the help of a pump. This arrangement offers a closed culture with less risk of contamination and maintains a minimum contact with the environment. The microalgae grow inside the pipes under incidence of ambient light. In this paper, harvesting, separation and drying were studied, as part of the processes of a sustainable energy plant under construction at UFPR, as shown in Fig. 1. To control the production in a photo-bioreactor in continuous system, it is necessary to monitor the concentration of microalgae growth in suspension. To measure the cell concentration in this equipment, an optic sensor has been developed. The microalgae biomass separation from the culture media is achieved by microalgae flocculation. Several cultivation situations have been tested with different NaOH concentrations, increasing the pH to 10. The system was kept under agitation during the addition by an air pump into the tank. Thereafter the system was maintained static. After a short time, it was observed that the microalgae coagulated and settled. The clarified part water was removed, remaining a concentrated microalgae suspension. Our results suggest that pH increase is a suitable methodology for microalgae separation from the growth suspension. The microalgae sedimentation time was recorded, which allowed the

Uso de Microalgas para Produção de Biodiesel

Directory of Open Access Journals (Sweden)

Gillianne Assis Carneiro

2018-01-01

Full Text Available A maioria das demandas energéticas da sociedade ainda são atendidas pelos combustíveis de origem fóssil. Porém, essa fonte vem sendo substituída por outras renováveis, menos agressivas ao meio ambiente e com melhor custo/benefício. Como exemplo, podemos mencionar os biocombustíveis produzidos a partir de plantas oleaginosas e microrganismos, que são capazes de substituir os derivados do petróleo com eficiência equivalente. Graças a sua elevada produção de lipídios, as microalgas, cujo diâmetro não ultrapassa 2 mm, são objeto de estudos e estão sendo aplicadas na produção de biocombustíveis, em especial, do biodiesel, sendo que, cerca de 150 espécies de microalgas são usadas comercialmente. O objetivo deste trabalho foi realizar uma revisão de literatura sobre a produção de biodiesel a partir de microalgas. Este estudo é do tipo teórico-conceitual, visto que foi elaborado a partir da realização de pesquisas na literatura nacional e internacional sobre a produção de biocombustíveis a partir de microalgas, além da consulta a órgãos governamentais e legislações pertinentes.  Ademais, pretende-se apresentar as principais técnicas de cultivo e de produção, bem como as principais vantagens e desvantagens da utilização das microalgas para produção de biodiesel. A partir da problemática ambiental e da redução das reservas fósseis faz-se necessário o investimento em fontes alternativas, sendo o biodiesel produzido a partir de microalgas uma opção a ser considerada e aperfeiçoada para produção e utilização em escala comercial.

Rapid biodiesel production using wet microalgae via microwave irradiation

International Nuclear Information System (INIS)

Wahidin, Suzana; Idris, Ani; Shaleh, Sitti Raehanah Muhamad

2014-01-01

Highlights: • Lipid was directly extracted from wet microalgae using microwave irradiation. • The microwave irradiation and water bath-assisted solvent extraction are applied. • Cell walls are significantly disrupted under microwave irradiation. • Highly disrupted cell walls led to higher biodiesel yield in microwave irradiation. • Microwave irradiation is a promising direct technique with high biodiesel yields. - Abstract: The major challenges for industrial commercialized biodiesel production from microalgae are the high cost of downstream processing such as dewatering and drying, utilization of large volumes of solvent and laborious extraction processes. In order to address these issues the microwave irradiation method was used to produce biodiesel directly from wet microalgae biomass. This alternative method of biodiesel production from wet microalgae biomass is compared with the conventional water bath-assisted solvent extraction. The microwave irradiation extracted more lipids and high biodiesel conversion was obtained compared to the water bath-assisted extraction method due to the high cell disruption achieved and rapid transesterification. The total content of lipid extracted from microwave irradiation and water bath-assisted extraction were 38.31% and 23.01% respectively. The biodiesel produced using microwave irradiation was higher (86.41%) compared to the conventional method. Thus microwave irradiation is an attractive and promising technology to be used in the extraction and transesterification process for efficient biodiesel production

Biodiesel Production from Microalgae by Extraction – Transesterification Method

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Nguyen Thi Phuong Thao

2013-11-01

Full Text Available The environmental impact of using petroleum fuels has led to a quest to find a suitable alternative fuel source. In this study, microalgae were explored as a highly potential feedstock to produce biodiesel fuel. Firstly, algal oil is extracted from algal biomass by using organic solvents (n–hexan.  Lipid is contained in microalgae up to 60% of their weight. Then, Biodiesel is created through a chemical reaction known as transesterification between algal oil and alcohol (methanol with strong acid (such as H2SO4 as the catalyst. The extraction – transesterification method resulted in a high biodiesel yield (10 % of algal biomass and high FAMEs content (5.2 % of algal biomass. Biodiesel production from microalgae was studied through experimental investigation of transesterification conditions such as reaction time, methanol to oil ration and catalyst dosage which are deemed to have main impact on reaction conversion efficiency. All the parameters which were characterized for purified biodiesel such as free glycerin, total glycerin, flash point, sulfur content were analyzed according to ASTM standardDoi: http://dx.doi.org/10.12777/wastech.1.1.6-9Citation:  Thao, N.T.P., Tin, N.T., and Thanh, B.X. 2013. Biodiesel Production from Microalgae by Extraction – Transesterification Method. Waste Technology 1(1:6-9. Doi: http://dx.doi.org/10.12777/wastech.1.1.6-9

Culture of microalgae biomass for valorization of table olive processing water

International Nuclear Information System (INIS)

Contreras, C.G.; Serrano, A.; Ruiz-Filippi, G.; Borja, R.; Fermoso, F.G.

2016-01-01

Table olive processing water (TOPW) contains many complex substances, such as phenols, which could be valorized as a substrate for microalgae biomass culture. The aim of this study was to assess the capability of Nannochloropsis gaditana to grow in TOPW at different concentrations (10- 80%) in order to valorize this processing water. Within this range, the highest increment of biomass was determined at percentage of 40% of TOPW, reaching an increment of 0.36 ± 0.05 mg volatile suspended solids (VSS)/L. Components of algal biomass were similar for the experiments at 10-40% of TOPW, where proteins were the major compounds (56-74%). Total phenols were retained in the microalgae biomass (0.020 ± 0.002 g of total phenols/g VSS). Experiments for 80% of TOPW resulted in a low production of microalgae biomass. High organic matter, nitrogen, phosphorus and phenol removal were achieved in all TOPW concentrations. Although high-value products, such as proteins, were obtained and high removal efficiencies of nutrients were determined, microalgae biomass culture should be enhanced to become a suitable integral processing water treatment. [es

Green energy from microalgae: Usage of algae biomass for anaerobic digestion

International Nuclear Information System (INIS)

Skorupskaite, Virginija; Makarevicie, Violeta

2014-01-01

The microalgae biomass can be used for various types of biofuels, including biodiesel and biogas. The aim of this study is to investigate the possibilities of microalgae Scenedesmus sp. and Chlorella sp. (widespread in freshwater Lithuanian lakes) usage for biogas production. Microalgae were cultivated under mixotrophic conditions (growth medium BG11 containing technical glycerol). In order to determine biogas yield and quality dependence on feedstock preparation, the analyses of biogas production have been performed with algae biomass prepared i n different ways: wet centrifuged; wet centrifuged, frozen and defrost; dry not de-oiled and dry de-oiled. The highest biogas yield in both cases (Scenedesmus sp. – 646 ml/gDM and Chlorella sp. – 652 ml/gDM) was obtained from centrifuged, frozen and defrost biomass. Biogas yield was app. 1.46 times higher comparing to yield of biogas produced from wastewater sludge. Our results showed that different types of biomass preparation have no significant influence on quality of biogas. Key words: microalgae, biomass, biogas production, biogas quality

Isolation and application of SOX and NOX resistant microalgae in biofixation of CO2 from thermoelectricity plants

International Nuclear Information System (INIS)

Radmann, Elisangela Martha; Vieira Camerini, Felipe; Duarte Santos, Thaisa; Vieira Costa, Jorge Alberto

2011-01-01

Highlights: → Microalgae can help reduce global warming. → Synechococcus nidulans and Chlorella vulgaris were isolated in a thermoelectric plant. → Microalgae were compared with Spirulina and Scenedesmus obliquus for CO 2 fixation. → Microalgae were exposed to CO 2 , SO 2 and NO, simulating a gas from coal combustion. → C. vulgaris and Spirulina sp. showed 13.43% of maximum daily fixation. - Abstract: Microalgae have been studied for their potential use in foodstuffs, agriculture, in the treatment of wastewater and, in particular, in the reduction of atmospheric carbon dioxide, the main cause of global warming. Thermoelectricity plants account for 22% of CO 2 emitted into the atmosphere and native microalgae may be more tolerant to the gases emitted from burning fossil fuels. In the study presented here, microalgae were isolated from ponds next to a Thermoelectricity Plant, located in southern Brazil, and identified as Synechococcus nidulans and Chlorella vulgaris. The isolated microalgae were grown and compared with two different strains of microalgae, Spirulina sp. and Scenedesmus obliquus, for CO 2 biofixation. The microalgae were exposed to 12% CO 2 , 60 ppm of SO 2 and 100 ppm of NO, simulating a gas from coal combustion. The C. vulgaris had similar behavior to Spirulina sp., with 13.43% of maximum daily fixation. The microalgae with the greater fixing capacity were C. vulgaris and Spirulina sp. and these can be grown in electric power plants for CO 2 biofixation of the coal combustion gas, which would help reduce global warming.

Potency of Microalgae as Biodiesel Source in Indonesia

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H Hadiyanto

2012-04-01

Full Text Available Within 20 years, Indonesia should find another energy alternative to substitutecurrent fossil oil. Current use of renewable energy is only 5% and need to be improved up to 17%of our energy mix program. Even though, most of the area in Indonesia is covered by sea, howeverthe utilization of microalgae as biofuel production is still limited. The biodiesel from currentsources (Jatropha, palm oil, and sorghum is still not able to cover all the needs if the fossil oilcannot be explored anymore. In this paper, the potency of microalgae in Indonesia was analysed asthe new potential of energy (biodiesel sources.

Thermogravimetric analysis of the gasification of microalgae Chlorella vulgaris.

Science.gov (United States)

Figueira, Camila Emilia; Moreira, Paulo Firmino; Giudici, Reinaldo

2015-12-01

The gasification of microalgae Chlorella vulgaris under an atmosphere of argon and water vapor was investigated by thermogravimetric analysis. The data were interpreted by using conventional isoconversional methods and also by the independent parallel reaction (IPR) model, in which the degradation is considered to happen individually to each pseudo-component of biomass (lipid, carbohydrate and protein). The IPR model allows obtaining the kinetic parameters of the degradation reaction of each component. Three main stages were observed during the gasification process and the differential thermogravimetric curve was satisfactorily fitted by the IPR model considering three pseudocomponents. The comparison of the activation energy values obtained by the methods and those found in the literature for other microalgae was satisfactory. Quantification of reaction products was performed using online gas chromatography. The major products detected were H2, CO and CH4, indicating the potential for producing fuel gas and syngas from microalgae. Copyright © 2015 Elsevier Ltd. All rights reserved.

Applicability of Euglena gracilis for biorefineries demonstrated by the production of α-tocopherol and paramylon followed by anaerobic digestion.

Science.gov (United States)

Grimm, Philipp; Risse, Joe M; Cholewa, Dominik; Müller, Jakob M; Beshay, Usama; Friehs, Karl; Flaschel, Erwin

2015-12-10

In this study the use of Euglena gracilis biomass for α-tocopherol, paramylon and biogas production in a value-added chain was investigated. Therefore, we analyzed the dry cell weight and product concentrations at different growth phases during heterotrophic, photoheterotrophic and photoautotrophic cultivation in a low-cost minimal medium. Furthermore, the specific biogas yields for differently derived biomass with and without product recovery were investigated. We demonstrate that growth phase and cultivation mode not only have a significant impact on product formation, but also influence the yield of biogas obtained from anaerobic digestion of Euglena gracilis biomass. The maximum dry cell weight concentration ranged from 12.3±0.14gL(-1) for heterotrophically to 3.4±0.02gL(-1) for photoautotrophically grown Euglena gracilis cells. The heterotrophically grown biomass accumulated product concentrations of 5.3±0.12mgL(-1) of α-tocopherol and 9.3±0.1gL(-1) of paramylon or 805±10.9mL of biogasgvs(-1) (per gram volatile solids). The results for photoautotrophically grown cells were 8.6±0.22mgL(-1) of α-tocopherol and 0.78±0.01gL(-1) of paramylon or 648±7.2mL of biogasgvs(-1). For an energy-saving downstream procedure the extracting agent methanol does not have to be removed strictly. Samples with residual methanol showed a significantly increased biogas yield, because the solvent can be used as an additional substrate for methane production by archaebacteria. Copyright © 2015 Elsevier B.V. All rights reserved.

Bio-gasification of post transesterified microalgae residues: A route to improving overall process renewabilities

DEFF Research Database (Denmark)

Ehimen, Ehiazesebhor Augustine

Using results from experiments and process modelling tools, a renewability assessment was carried out for the use of the conventional and in-situ transesterification processes for a large scale microalgae biodiesel production. In a present day scenario, all the transesterification processes were...... shown to be non-renewable. The process renewability of biodiesel production from microalgae was found to significantly improve with the use of renewable electricity, reacting alcohols from biomass fermentation and process heating and biomass drying using heat from wood pellet combustion or heat pump...... technology. The anaerobic digestion of the microalgae residues to generate methane from was further seen to lead to positive renewabilities for the considered microalgae-biodiesel processes....

Pyrolysis characteristics and kinetics of microalgae via thermogravimetric analysis (TGA): A state-of-the-art review.

Science.gov (United States)

Bach, Quang-Vu; Chen, Wei-Hsin

2017-12-01

Pyrolysis is a promising route for biofuels production from microalgae at moderate temperatures (400-600°C) in an inert atmosphere. Depending on the operating conditions, pyrolysis can produce biochar and/or bio-oil. In practice, knowledge for thermal decomposition characteristics and kinetics of microalgae during pyrolysis is essential for pyrolyzer design and pyrolysis optimization. Recently, the pyrolysis kinetics of microalgae has become a crucial topic and received increasing interest from researchers. Thermogravimetric analysis (TGA) has been employed as a proven technique for studying microalgae pyrolysis in a kinetic control regime. In addition, a number of kinetic models have been applied to process the TGA data for kinetic evaluation and parameters estimation. This paper aims to provide a state-of-the art review on recent research activities in pyrolysis characteristics and kinetics of various microalgae. Common kinetic models predicting the thermal degradation of microalgae are examined and their pros and cons are illustrated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Harvesting of microalgae by bio-flocculation

NARCIS (Netherlands)

Salim, S.; Bosma, R.; Vermuë, M.H.; Wijffels, R.H.

2011-01-01

The high-energy input for harvesting biomass makes current commercial microalgal biodiesel production economically unfeasible. A novel harvesting method is presented as a cost and energy efficient alternative: the bio-flocculation by using one flocculating microalga to concentrate the

Screening of antioxidant activity in microalgae

Directory of Open Access Journals (Sweden)

Mariana F.G. Assunção

2014-06-01

Both sets of results indicate an interesting antioxidant potential in microalgae belonging to the groups Eustigmatophyceae and Chlorophyceae. Tested species of these groups showed ABTS•+ values comparable to grape and raspberry ethanolic extracts, confirmed also by the DPPH• method.

Acaricidal efficacies of Lippia gracilis essential oil and its phytochemicals against organophosphate-resistant and susceptible strains of Rhipicephalus (Boophilus) microplus

Science.gov (United States)

Plant-derived natural products can serve as an alternative to synthetic compounds for control of ticks of veterinary and medical importance. Lippia gracilis is an aromatic plant that produces essential oil with high content of carvacrol and thymol monoterpenes. These monoterpenes have high acaricida...

Growth of locally isolated microalga in POME to produce lipid as alternative energy sources

Science.gov (United States)

Elvitriana; Munir, E.; Delvian; Wahyuningsih, H.

2018-04-01

Purpose of this study was to find the best growth of locally isolated microalgae that produce lipids from Palm Oil Mill Effluent (POME) as an alternative energy source. Microalgae was cultivated in POME in glass vessel at room temperature using a lighting intensity of 13,000 lux and continuously aeration for 24 and 12 hours, respectively. Biomass of microalgae were analyzed daily to get their growth by spectrophotometry at 624 nm wavelength, whereas Modified Bligh and Dyer method determined lipid content. Results show that the best growth occurred at 10% inoculum with lighting cycle and aeration of 24 hours (on/off) and resulting highest biomass content of 0.99 g dry weight/L followed by the decrease of organic substances in POME. The percentage reduction of COD, BOD, TSS, and oil at POME reached above 92%, while phosphate concentration reached 89.2%. Cultivation of microalgae in POME for 12 days showed its ability to reduce organic substances and nutrients in POME and produced biomass with lipid content of 35%. These results reached to the conclusion that locally isolated microalgae has an ability to treat POME safely for environment and POME can be used as a growing medium of microalgae that produces lipids.

A Saponification Method for Chlorophyll Removal from Microalgae Biomass as Oil Feedstock

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Tao Li

2016-09-01

Full Text Available Microalgae oil is an optimal feedstock for nutraceutical, pharmaceutical and biodiesel production, but its high levels of chlorophyll limit its large-scale application. To date, few effective approaches have been developed to remove chlorophyll from microalgae oil. The main purpose of this study was to present a preprocessing method of algae oil feedstock (Scenedesmus to remove chlorophyll by saponification. The results showed that 96% of chlorophyll in biomass was removed. High quality orange transparent oil could be extracted from the chlorophyll reduced biomass. Specifically, the proportion of neutral lipids and saturation levels of fatty acids increased, and the pigments composition became carotenoids-based. The critical parameters of chlorophyll reduced biodiesel conformed to the standards of the USA, China and EU. Sodium copper chlorophyllin could be prepared from the bleaching effluent. The results presented herein offer a useful pathway to improve the quality of microalgae oil and reduce the cost of microalgae biodiesel.

A Saponification Method for Chlorophyll Removal from Microalgae Biomass as Oil Feedstock

Science.gov (United States)

Li, Tao; Xu, Jin; Wu, Hualian; Wang, Guanghua; Dai, Shikun; Fan, Jiewei; He, Hui; Xiang, Wenzhou

2016-01-01

Microalgae oil is an optimal feedstock for nutraceutical, pharmaceutical and biodiesel production, but its high levels of chlorophyll limit its large-scale application. To date, few effective approaches have been developed to remove chlorophyll from microalgae oil. The main purpose of this study was to present a preprocessing method of algae oil feedstock (Scenedesmus) to remove chlorophyll by saponification. The results showed that 96% of chlorophyll in biomass was removed. High quality orange transparent oil could be extracted from the chlorophyll reduced biomass. Specifically, the proportion of neutral lipids and saturation levels of fatty acids increased, and the pigments composition became carotenoids-based. The critical parameters of chlorophyll reduced biodiesel conformed to the standards of the USA, China and EU. Sodium copper chlorophyllin could be prepared from the bleaching effluent. The results presented herein offer a useful pathway to improve the quality of microalgae oil and reduce the cost of microalgae biodiesel. PMID:27618070

A Saponification Method for Chlorophyll Removal from Microalgae Biomass as Oil Feedstock.

Science.gov (United States)

Li, Tao; Xu, Jin; Wu, Hualian; Wang, Guanghua; Dai, Shikun; Fan, Jiewei; He, Hui; Xiang, Wenzhou

2016-09-07

Microalgae oil is an optimal feedstock for nutraceutical, pharmaceutical and biodiesel production, but its high levels of chlorophyll limit its large-scale application. To date, few effective approaches have been developed to remove chlorophyll from microalgae oil. The main purpose of this study was to present a preprocessing method of algae oil feedstock (Scenedesmus) to remove chlorophyll by saponification. The results showed that 96% of chlorophyll in biomass was removed. High quality orange transparent oil could be extracted from the chlorophyll reduced biomass. Specifically, the proportion of neutral lipids and saturation levels of fatty acids increased, and the pigments composition became carotenoids-based. The critical parameters of chlorophyll reduced biodiesel conformed to the standards of the USA, China and EU. Sodium copper chlorophyllin could be prepared from the bleaching effluent. The results presented herein offer a useful pathway to improve the quality of microalgae oil and reduce the cost of microalgae biodiesel.

Culture of microalgae biomass for valorization of table olive processing water

Directory of Open Access Journals (Sweden)

Contreras, C. G.

2016-09-01

Full Text Available Table olive processing water (TOPW contains many complex substances, such as phenols, which could be valorized as a substrate for microalgae biomass culture. The aim of this study was to assess the capability of Nannochloropsis gaditana to grow in TOPW at different concentrations (10- 80% in order to valorize this processing water. Within this range, the highest increment of biomass was determined at percentage of 40% of TOPW, reaching an increment of 0.36 ± 0.05 mg volatile suspended solids (VSS/L. Components of algal biomass were similar for the experiments at 10-40% of TOPW, where proteins were the major compounds (56-74%. Total phenols were retained in the microalgae biomass (0.020 ± 0.002 g of total phenols/g VSS. Experiments for 80% of TOPW resulted in a low production of microalgae biomass. High organic matter, nitrogen, phosphorus and phenol removal were achieved in all TOPW concentrations. Although high-value products, such as proteins, were obtained and high removal efficiencies of nutrients were determined, microalgae biomass culture should be enhanced to become a suitable integral processing water treatment.El agua resultante del proceso de elaboración de la aceituna de mesa (TOPW presenta un elevado contenido en sustancias complejas, como fenoles, que podría permitir su uso como sustrato para el cultivo de microalgas. El objetivo de este estudio se centra en evaluar la capacidad de crecimiento de Nannochloropsis gaditana en TOPW a distintas concentraciones (10-80% con vistas a la valorización de estas aguas. El mayor incremento de biomasa se obtuvo para un porcentaje del 40% de TOPW, alcanzando un aumento de 0.36 ± 0.50 mg sólidos en suspensión volátiles (SSV/L. Los componentes presentes en la biomasa han sido similares para los experimentos con 10-40% de TOPW, siendo las proteínas los compuestos mayoritarios en todos los casos (56-74%. Los fenoles totales quedaron retenidos en las microalgas, alcanzando una concentraci

Mathematical modeling and experimental validation of Phaeodactylum tricornutum microalgae growth rate with glycerol addition

Energy Technology Data Exchange (ETDEWEB)

Morais, Keli Cristiane Correia; Ribeiro, Robert Luis Lara; Santos, Kassiana Ribeiro dos; Mariano, Andre Bellin [Mariano Center for Research and Development of Sustainable Energy (NPDEAS), Curitiba, PR (Brazil); Vargas, Jose Viriato Coelho [Departament of Mechanical Engineering, Federal University of Parana (UFPR) Curitiba, PR (Brazil)

2010-07-01

The Brazilian National Program for Bio fuel Production has been encouraging diversification of feedstock for biofuel production. One of the most promising alternatives is the use of microalgae biomass for biofuel production. The cultivation of microalgae is conducted in aquatic systems, therefore microalgae oil production does not compete with agricultural land. Microalgae have greater photosynthetic efficiency than higher plants and are efficient fixing CO{sub 2}. The challenge is to reduce production costs, which can be minimized by increasing productivity and oil biomass. Aiming to increase the production of microalgae biomass, mixotrophic cultivation, with the addition of glycerol has been shown to be very promising. During the production of biodiesel from microalgae there is availability of glycerol as a side product of the transesterification reaction, which could be used as organic carbon source for microalgae mixotrophic growth, resulting in increased biomass productivity. In this paper, to study the effect of glycerol in experimental conditions, the batch culture of the diatom Phaeodactylum tricornutum was performed in a 2-liter flask in a temperature and light intensity controlled room. During 16 days of cultivation, the number of cells per ml was counted periodically in a Neubauer chamber. The calculation of dry biomass in the control experiment (without glycerol) was performed every two days by vacuum filtration. In the dry biomass mixotrophic experiment with glycerol concentration of 1.5 M, the number of cells was assessed similarly in the 10{sup th} and 14{sup th} days of cultivation. Through a volume element methodology, a mathematical model was written to calculate the microalgae growth rate. It was used an equation that describes the influence of irradiation and concentration of nutrients in the growth of microalgae. A simulation time of 16 days was used in the computations, with initial concentration of 0.1 g l{sup -1}. In order to compare

MICROALGAE AS AN ALTERNATIVE TO BIOFUELS PRODUCTION. PART 1: BIOETHANOL

Directory of Open Access Journals (Sweden)

Maiara Priscilla de Souza

2013-02-01

Full Text Available The demand from the energy sector is one of the culminating factors to do researches that enable innovations in the biotechnology sector and to boost biofuel production. The variability of the existing feedstocks provides benefits to energy production, however, we must choose the ones that present plausible characteristics depending on the type of product that we want to obtained. In this context, it is noted that the microalgae have suitable characteristics to producing different types of fuels, depending on the type of treatment are subjected, the species being analyzed as well as the biochemical composition of the biomass. Bioethanol production from microalgae is a promising and growing energy alternative under a view that biomass of these microorganisms has an enormous biodiversity and contain high levels of carbohydrates, an indispensable factor for the bioconversion of microalgae in ethanol. Due to these factors, there is a constant search for more viable methods for pretreatment of biomass, hydrolysis and fermentation, having as one of the major aspects the approach of effectives methodologies in the ambit of quality and yield of ethanol. Therefore, we have to search to increase the interest in the developing of biofuels reconciling with the importance of using microalgae, analyzing whether these micro-organisms are capable of being used in bioethanol production.

Characterization of the flocculating agent from the spontaneously flocculating microalga Chlorella vulgaris JSC-7.

Science.gov (United States)

Alam, Md Asraful; Wan, Chun; Guo, Suo-Lian; Zhao, Xin-Qing; Huang, Zih-You; Yang, Yu-Liang; Chang, Jo-Shu; Bai, Feng-Wu

2014-07-01

High cost of biomass recovery is one of the bottlenecks for developing cost-effective processes with microalgae, particularly for the production of biofuels and bio-based chemicals through biorefinery, and microalgal biomass recovery through cell flocculation is a promising strategy. Some microalgae are naturally flocculated whose cells can be harvested by simple sedimentation. However, studies on the flocculating agents synthesized by microalgae cells are still very limited. In this work, the cell flocculation of a spontaneously flocculating microalga Chlorella vulgaris JSC-7 was studied, and the flocculating agent was identified to be cell wall polysaccharides whose crude extract supplemented at low dosage of 0.5 mg/L initiated the more than 80% flocculating rate of freely suspended microalgae C. vulgaris CNW11 and Scenedesmus obliquus FSP. Fourier transform infrared (FTIR) analysis revealed a characteristic absorption band at 1238 cm(-1), which might arise from PO asymmetric stretching vibration of [Formula: see text] phosphodiester. The unique cell wall-associated polysaccharide with molecular weight of 9.86×10(3) g/mol, and the monomers consist of glucose, mannose and galactose with a molecular ratio of 5:5:2. This is the first time to our knowledge that the flocculating agent from C. vulgaris has been characterized, which could provide basis for understanding the cell flocculation of microalgae and breeding of novel flocculating microalgae for cost-effective biomass harvest. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Setting the conditions for phycoremediation of radionuclide microalgae Dunaliella salina and Chlorella vulgaris

International Nuclear Information System (INIS)

Tatarova, D.; Galanda, D.; Kuruc, J.

2016-01-01

This presentation deals with bioremediation using microalgae - by phycoremediation. Microalgae are economically low profile compared to the plants, their cultivation can be carried out in laboratory conditions. They can survive in extreme conditions, they occur in all habitats and have faster growth. Halophilous green D. salina can accumulate heavy metals such as Zn, Cu and Cd. It occurs in hypersaline environment with tolerance (0.2 to 35) % NaCl. It contains high amounts of carotenoids, which protect it against formation of free radicals from UV radiation. Chlorella vulgaris is a representative of eukaryotic green microalgae with the highest chlorophyll content with the appearance in fresh water. Its phycoremediant ability are found in N and P elements, which are used as its nutritional components as well as for Cu, Cr, Cd, Pb, Au. The experiments were carried out using a peristaltic pump ISMATEC Model: ISM851 (flow rate 2 cm"3 min"-"1) followed by monitoring of time dependence of decrease of activity of the microalgae solutions. For evaluation of the samples was used HPGe gamma spectrometer (measurement time of the samples: 600 sec) from ORTEC Company and measured spectra were evaluated with software GammaVision from ORTEC. The measured results showed that the most effective phycoremediation of microalgae Dunaliella salina toke place in an environment of pH 3, and even more at pH 8. The fact that the D. salina is able of phycoremediation at so acidic pH can contribute to its applications in extreme conditions or in the coastal areas in view of that it is halophilic. At freshwater microalgae Chlorella vulgaris was found the best phytoremediation potential in its natural environment at pH of 6. Because this microalgae is freshwater, it may find application in inland or in liquid radioactive waste from nuclear facilities.(authors)

Pyrolysis mechanism of microalgae Nannochloropsis sp. based on model compounds and their interaction

International Nuclear Information System (INIS)

Wang, Xin; Tang, Xiaohan; Yang, Xiaoyi

2017-01-01

Highlights: • Pyrolysis experiments were conducted by model compounds of algal components. • Interaction affected little bio-crude yield of model compounds co-pyrolysis. • Some interaction pathways between microalgae components were recommended. • N-heterocyclic compounds were further pyrolysis products of Maillard reaction products. • Surfactant synthesis (lipid-amino acids and lipid-glucose) between algal components. - Abstract: Pyrolysis is one of important pathways to convert microalgae to liquid biofuels and key components of microalgae have different chemical composition and structure, which provides a barrier for large-scale microalgae-based liquid biofuel application. Microalgae component pyrolysis mechanism should be researched to optimal pyrolysis process parameters. In this study, single pyrolysis and co-pyrolysis of microalgal components (model compounds castor oil, soybean protein and glucose) were conducted to reveal interaction between them by thermogrametric analysis and bio-crude evaluation. Castor oil (model compound of lipid) has higher pyrolysis temperature than other model compounds and has the maximum contribution to bio-crude formation. Bio-crude from soybean protein has higher N-heterocyclic compounds as well as phenols, which could be important aromatic hydrocarbon source during biorefineries and alternative aviation biofuel production. Potential interaction pathways based on model compounds are recommended including further decomposition of Maillard reaction products (MRPs) and surfactant synthesis, which indicate that glucose played an important role on pyrolysis of microalgal protein and lipid components. The results should provide necessary information for microalgae pyrolysis process optimization and large-scale pyrolysis reactor design.

Effect of γ-irradiation on Euglena gracilis Algae

International Nuclear Information System (INIS)

Hlinkova, E.; Zhuchkina, N.I.; Koltovaya, N.A.; Koltovoj, N.A.

2011-01-01

Given the prospects for using Euglena algae as part of the biological systems of human life support in long-term space flights, we studied the effects of low doses of radiation and genotype influence on the radiosensitivity of Euglena cells. Irradiation of several Euglena gracilis strains with 60 Co γ-rays shows that strain Z is the most radioresistant. Its chloroplastless derivate OFL strain shows increased radiosensitivity. The E. bacillaris strain and its derivates W3 and W10 without chlorophyll have intermediate radiosensitivity. Irradiation up to 10 Gy had the hormesis effect on the initial strains, and it is only above 100 Gy that cell death was observed. The hormesis effect was observed concerning both radioresistance and growth rate. The use of methylen blue and fluorochrome dyes allows a rapid estimation of the share of the living and dead cells. A comparison of two survival rate tests shows that the classical method of plating on a growth medium yields an increased death rate because this method does not take into account the living non-dividing cells

Active compounds from cyanobacteria and microalgae: properties and potential applications in biomedicine

Directory of Open Access Journals (Sweden)

Alexey Llopiz

2016-05-01

Full Text Available Cyanobacteria and microalgae are source of many chemicals substances with potential applications on biopharmaceutical industry. Many structures have been characterized in these organism, such as: peptides, proteins, carbohydrates, terpenoids, polyinsatured fatty acids, flavonoids, phenolic compounds, vitamins, porfirins and other organic substances. Chemicals structures of isolated compounds are diverse and it depends of microalgae habitats. Pharmacological activities located in microalgae are bactericides, immunomodulatory, antioxidants, cytoprotective, fungicides and antivirals. These properties may possible the potential treatment of many diseases including autoimmunes disorders, tumoral, and infectious process. In this review are presented and discussed some elements associated to chemical structure and biological activities around of compounds with potential uses as biopharmaceuticals.

Techno-economic assessment of micro-algae as feedstock for renewable bio-energy production

NARCIS (Netherlands)

Jonker, J.G.G.; Faaij, A.P.C.|info:eu-repo/dai/nl/10685903X

2013-01-01

This paper determines the energy consumption ratio and overall bio-energy production costs of microalgae cultivation, harvesting and conversion to secondary energy carriers, thus helping to clarify future perspectives of micro-algae production for energy purposes. A limitation growth model is

Potency of Microalgae as Biodiesel Source in Indonesia

Directory of Open Access Journals (Sweden)

H Hadiyanto

2012-02-01

Full Text Available Within 20 years, Indonesia should find another energy alternative to substitute current fossil oil. Current use of renewable energy is only 5% and need to be improved up to 17% of our energy mix program. Even though, most of the area in Indonesia is covered by sea, however the utilization of microalgae as biofuel production is still limited. The biodiesel from current sources (Jatropha, palm oil, and sorghum is still not able to cover all the needs if the fossil oil cannot be explored anymore. In this paper, the potency of microalgae in Indonesia was analysed as the new potential of energy (biodiesel sources.

Cultivation of microalgae Spirulina platensis (Arthrospira platensis from biological treatment of swine wastewater Cultivo da microalga Spirulina platensis (Arthrospira platensis a partir de tratamento biológico de efluente suíno

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Natália Mezzomo

2010-03-01

Full Text Available The microalgae biomass production from swine wastewater is a possible solution for the environmental impact generated by wastewater discharge into water sources. The biomass can be added to fish feed, which can be used in the formulation of meat products. This work addresses the adaptation of the microalgae Spirulina platensis (Arthrospira platensis in swine wastewater and the study of the best dilution of the wastewater for maximum biomass production and for removal of Chemical Oxygen Demand (COD, ammonia and phosphorous to the microalgae. The cultivation of Spirulina platensis, strain Paracas presented maximum cellular concentrations and maximum specific growth rates in the wastewater concentration of 5.0 and 8.5%. The highest COD removals occurred with 26.5 and 30.0% of wastewater in the medium. The maximum removal of total phosphorous (41.6%, was with 8.5% of wastewater, which is related to the microalgae growth. The results of Spirulina culture in the swine wastewater demonstrated the possibility of using these microalgae for the COD and phosphorous removal and for biomass production.A produção de biomassa de microalgas a partir de efluente suíno consiste em uma possível solução para o impacto ambiental gerado pela descarga de efluentes em fontes naturais. A biomassa produzida pode ser adicionada a rações de peixes, os quais podem ser utilizados na formulação de produtos cárneos. O objetivo deste trabalho foi a adaptação da microalga Spirulina platensis (Arthrospira platensis em efluente suíno e o estudo da diluição ideal de efluente para obter a máxima produção de biomassa e remoção de Demanda Química de Oxigênio (DQO, amônia e fósforo do efluente pela microalga. O cultivo da Spirulina platensis, cepa Paracas apresentou máxima concentração celular e máxima taxa específica de crescimento em concentrações de efluente de 5,0 e 8,5%. As maiores remoções de DQO ocorreram com 26,5 e 30,0% de efluente no meio. A

Microalgae: cultivation techniques and wastewater phycoremediation.

Science.gov (United States)

Pacheco, Marcondes M; Hoeltz, Michele; Moraes, Maria S A; Schneider, Rosana C S

2015-01-01

Generation of liquid and gaseous effluents is associated with almost all anthropogenic activities. The discharge of these effluents into the environment without treatment has reduced the availability and quality of natural resources, representing a serious threat to the balance of different ecosystems and human health. Universal access to water and global warming are topics of intense concern and are listed as priorities in the vast majority of global scientific, social and political guidelines. Conventional techniques to treat liquid and gaseous effluents pose economic and/or environmental limitations that prevent their use in certain applications. The technique of phycoremediation, which uses microalgae, macroalgae, and cyanobacteria for the removal or biotransformation of pollutants, is an emerging technology that has been highlighted due to its economic viability and environmental sustainability. This literature review discusses different techniques of microalgae cultivation and their use in the phycoremediation of contaminants in wastewater.

Microalgae for Biofuels and Animal Feeds

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John Benemann

2013-11-01

Full Text Available The potential of microalgae biomass production for low-cost commodities—biofuels and animal feeds—using sunlight and CO2 is reviewed. Microalgae are currently cultivated in relatively small-scale systems, mainly for high value human nutritional products. For commodities, production costs must be decreased by an order of magnitude, and high productivity algal strains must be developed that can be stably cultivated in large open ponds and harvested by low-cost processes. For animal feeds, the algal biomass must be high in digestible protein and long-chain omega-3 fatty acids that can substitute for fish meal and fish oils. Biofuels will require a high content of vegetable oils (preferably triglycerides, hydrocarbons or fermentable carbohydrates. Many different cultivation systems, algal species, harvesting methods, and biomass processing technologies are being developed worldwide. However, only raceway-type open pond systems are suitable for the production of low-cost commodities.

Lipid profiling of some authotrophic microalgae grown on waste water

DEFF Research Database (Denmark)

Safafar, Hamed; Jacobsen, Charlotte; Møller, Per

Microalgae can be a new source of lipids for the aquaculture industry. Moreover, their potential as natural sources of antioxidants has gained recent attention. About 40 species of microalgae are used in aquaculture worldwide. A full characterization of lipid components is critical for selecting...... by membrane microfiltration and analyzed for fatty acid (GC), triacylglycerol (HPLC), sterol (GC) and tochol (HPLC) composition and also for amounts of phospholipids . Lipid composition in micro algae varied strongly between species....

Review of the South American characiform fish genus Chilodus, with description of a new species, C. gracilis (Pisces, Characiformes, Chilodontidae)

NARCIS (Netherlands)

Isbrücker, I.J.H.; Nijssen, H.

1988-01-01

Examination of 291 specimens of Chilodus, a genus of South American fresh water fishes, yielded the presence of three species, viz.: C. punctatus, C. zunevei, and C. gracilis. Of the first species the lectotype is designated. The type material of C. zunevei is lost; new material enabled a

Production of structured triacylglycerols from microalgae

Czech Academy of Sciences Publication Activity Database

Řezanka, Tomáš; Lukavský, Jaromír; Nedbalová, Linda; Sigler, Karel

2014-01-01

Roč. 104, AUG 2014 (2014), s. 95-104 ISSN 0031-9422 R&D Projects: GA ČR(CZ) GAP503/11/0215 Institutional support: RVO:61388971 ; RVO:67985939 Keywords : microalgae * enantiomers * chiral LC Subject RIV: EE - Microbiology, Virology Impact factor: 2.547, year: 2014

Enhancement of growth and lipid production from microalgae using fluorescent paint under the solar radiation.

Science.gov (United States)

Seo, Yeong Hwan; Cho, Changsoon; Lee, Jung-Yong; Han, Jong-In

2014-12-01

Solar radiation has intensity that is too high to inhibit microalgae activity and is composed of wide light spectrum including ultraviolet (UV) range which cannot be utilized for microalgae. For these reasons, the modification of solar radiation is required for effective microalgae cultivation, and to do that, fluorescent paint was used for not only blocking excessive solar energy but also converting UV to visible light. With fluorescent aqueous layer, microalgae was protected from photoinhibition and could grow well, but there was difference in growth and lipid accumulation efficiencies depending on the color; maximum dry weight of 1.7 g/L was achieved in red paint, whereas best lipid content of 30% was obtained in blue one. This phenomenon was due to the different light spectrum made by colors. With simple process using fluorescent paint, modification of light was successfully done and allowing microalgae to grow under strong radiation such as solar radiation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Current Status and Outlook in the Application of Microalgae in Biodiesel Production and Environmental Protection

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xin [Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan (China); University of Chinese Academy of Sciences, Beijing (China); Rong, Junfeng [SINOPEC Research Institute of Petroleum Processing, Beijing (China); Chen, Hui; He, Chenliu; Wang, Qiang, E-mail: wangqiang@ihb.ac.cn [Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan (China)

2014-08-19

Microalgae have been currently recognized as a group of the most potential feedstocks for biodiesel production due to high productivity potential, efficient biosynthesis of lipids, and less competition with food production. Moreover, utilization of microalgae with environmental purposes (CO{sub 2} fixation, NO{sub x}, and wastewater treatment) and biorefinery has been reported. However, there are still challenges that need to be addressed to ensure stable large-scale production with positive net energy balance. This review gives an overview of the current status of the application of microalgae in biodiesel production and environmental protection. The practical problems not only facing the microalgae biodiesel production but also associated with microalgae application for environmental pollution control, in particular biological fixation of greenhouse gas (CO{sub 2} and NO{sub x}) and wastewater treatment are described in detail. Notably, the synergistic combination of various applications (e.g., food, medicine, wastewater treatment, and flue gas treatment) with biodiesel production could enhance the sustainability and economics of the algal biodiesel production system.

Current status and outlook in the application of microalgae in biodiesel production and environmental protection

Directory of Open Access Journals (Sweden)

Xin eZhang

2014-08-01

Full Text Available Microalgae have been currently recognized as one group of the most potential feedstocks for biodiesel production due to high productivity potential, efficient biosynthesis of lipids and less competition with food production. Moreover, utilization of microalgae with environmental purposes (CO2 fixation, NOX and wastewater treatment and biorefinery have been reported. However, there are still challenges that need to be addressed to ensure stable large-scale production with positive net energy balance. This review gives an overview of the current status of the application of microalgae in biodiesel production and environmental protection. The practical problems not only facing the microalgae biodiesel production but also associated with microalgae application for environmental pollution control, in particular biological fixation of greenhouse gas (CO2 and NOX and wastewater treatment are described in detail. Notably, the synergistic combination of various applications (e.g. food, medicine, wastewater treatment and flue gas treatment with biodiesel production could enhance the sustainability and economics of the algal biodiesel production system.

Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

Science.gov (United States)

Booij, Petra; Sjollema, Sascha B.; van der Geest, Harm G.; Leonards, Pim E. G.; Lamoree, Marja H.; de Voogt, W. Pim; Admiraal, Wim; Laane, Remi W. P. M.; Vethaak, A. Dick

2015-08-01

For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and coastal waters are the most productive ecosystems with high primary production by microalgae. The toxic pressure of specific phytotoxic chemicals now poses a major threat to these ecosystems. In a previous study, six herbicides (atrazine, diuron, irgarol, isoproturon, terbutryn and terbutylazine) were identified as the main contaminants affecting photosynthesis in marine microalgae. The purpose of this study is to investigate the toxic pressure of these herbicides in the Dutch estuarine and coastal waters in relation to the effective photosystem II efficiency (ΦPSII) in microalgae. Temporal and spatial variations in the concentrations of these herbicides were analyzed based on monitoring data. Additionally, a field study was carried out in which chemical analysis of water was performed and also a toxicity assessment using the Pulse Amplitude Modulation (PAM) fluorometry assay that measures ΦPSII. The toxic pressure on ΦPSII in microalgae has decreased with 55-82% from 2003 to 2012, with the Western Scheldt estuary showing the highest toxic pressure. By combining toxicity data from the PAM assay with chemical analysis of herbicide concentrations, we have identified diuron and terbutylazine as the main contributors to the toxic pressure on microalgae. Although direct effects are not expected, the toxic pressure is close to the 10% effect level in the PAM assay. A compliance check with the current environmental legislation of the European Union revealed that the quality standards are not sufficient to protect marine microalgae.

Microalgae wet extraction using N-ethyl butylamine for fatty acid production

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Ying Du

2016-04-01

Full Text Available Microalgae are considered a promising feedstock for the production of food ingredients, cosmetics, pharmaceutical products and biofuels. The energy intensity of drying and cell breaking of algae and solvent recovery afterwards hindered the route of algae biorefinery. In this work the influences of freeze drying and cell breaking to the extraction efficiency of crude lipid yield and fatty acid yield were investigated. Results showed that drying and cell breaking are not necessary for N-ethyl butylamine extraction, because good yields were obtained without. Crude lipid yield and fatty acid yield using N-ethyl butylamine were comparable with Bligh & Dyer extraction, making N-ethyl butylamine a candidate for further development of an energy efficient lipid extraction technology for non-broken microalgae. Keywords: Microalgae, Lipids, Extraction, Switchable solvent, Secondary amine

Optimal control of nutrition restricted dynamics model of Microalgae biomass growth model

Science.gov (United States)

Ratianingsih, R.; Azim; Nacong, N.; Resnawati; Mardlijah; Widodo, B.

2017-12-01

The biomass of the microalgae is very potential to be proposed as an alternative renewable energy resources because it could be extracted into lipid. Afterward, the lipid could be processed to get the biodiesel or bioethanol. The extraction of the biomass on lipid synthesis process is very important to be studied because the process just gives some amount of lipid. A mathematical model of restricted microalgae biomass growth just gives 1/3 proportion of lipid with respect to the biomass in the synthesis process. An optimal control is designed to raise the ratio between the number of lipid formation and the microalgae biomass to be used in synthesis process. The minimum/ Pontryagin maximum principle is used to get the optimal lipid production. The simulation shows that the optimal lipid formation could be reach by simultaneously controlling the carbon dioxide, in the respiration and photosynthesis the process, and intake nutrition rates of liquid waste and urea substrate. The production of controlled microalgae lipid could be increase 6.5 times comparing to the uncontrolled one.

Moringa oleifera Seed Derivatives as Potential Bio-Coagulant for Microalgae Chlorella sp. Harvesting

International Nuclear Information System (INIS)

Azizah Endut; Azizah Endut; Siti Hajar Abdul Hamid; Fathurrahman Lananan; Helena Khatoon

2016-01-01

Microalgae is an economical and potential raw material of biomass energy, which offer a wide range of commercial potential to produce valuable substances for applications in aquaculture feed, pharmaceutical purposes and bio fuels production. However, lack of an economical, efficient and convenient method to harvest microalgae is a bottleneck to boost their full-scale application. Hence, this study was performed to investigate the potentialities of Moringa oleifera seed derivatives as an environmentally bio-coagulant to harvest microalgae Chlorella sp. biomass from the water column, which acts as a binder to coagulate particulate impurities to form larger aggregates. Results shown M. oleifera to have better biomass recovery of 122.51 % as compared to 37.08 % of alum at similar dosages of 10 mgL"-"1. In addition, it was found that the zeta potential values of mixed microalgae-coagulant suspension shows positive correlation on the flocculation parameters. For biomass recovery, the correlation for M. oleifera protein powder showed the R"2-value of 0.9565 whereas the control chemical flocculant, alum with the R"2-value of 0.7920. It was evidence that M. oleifera has a great potential in efficient and economical for environmentally microalgae harvesting and the adaptation of biological harvesting technology especially for the purpose of aquaculture feed in Malaysia. (author)

The kinetics of Scenedesmus obliquus microalgae growth utilizing carbon dioxide gas from biogas

International Nuclear Information System (INIS)

Thiansathit, Worrarat; Keener, Tim C.; Khang, Soon-Jai; Ratpukdi, Thunyalux; Hovichitr, Patcharee

2015-01-01

Microalgae Scenedesmus obliquus was cultured in a laboratory photobioreactor to determine the efficacy of using biogas as a carbon source for the microalgae's growth. The biogas contained ∼60% CH 4 and ∼40% CO 2 , and was derived from an anaerobic digester operating from animal wastes, and an anaerobic reactor utilizing high strength wastewater. The results showed that biogas is a viable carbon source for microalgae growth and that significant portions of the biogas' CO 2 can be utilized for algae growth, resulting in a biogas having a high concentration of methane. This paper develops the kinetic expressions for the algae's growth by assuming an autocatalytic reaction between carbon substrate and microalgae. The maximum specific growth rate and biomass productivity of S. obliquus were 0.56 d −1 and 0.145 g L −1 d −1 respectively. The biomass contained 51.8% carbon and higher heating value (HHV) was 22.9 MJ kg −1 . - Highlights: • Biogas is a viable carbon source for microalgae growth. • Biomass production rate and characteristics were assessed. • Scenedesmus obliquus can adjust to grow with high concentration of CO 2 in the carbon source

Modifications of the metabolic pathways of lipid and triacylglycerol production in microalgae

Directory of Open Access Journals (Sweden)

Yu Wei-Luen

2011-11-01

Full Text Available Abstract Microalgae have presented themselves as a strong candidate to replace diminishing oil reserves as a source of lipids for biofuels. Here we describe successful modifications of terrestrial plant lipid content which increase overall lipid production or shift the balance of lipid production towards lipid varieties more useful for biofuel production. Our discussion ranges from the biosynthetic pathways and rate limiting steps of triacylglycerol formation to enzymes required for the formation of triacylglycerol containing exotic lipids. Secondarily, we discuss techniques for genetic engineering and modification of various microalgae which can be combined with insights gained from research in higher plants to aid in the creation of production strains of microalgae.

Catch composition of the spiny lobster Panulirus gracilis (Decapoda: Palinuridae off the western coast of Mexico Composición de la captura de la langosta espinosa Panulirus gracilis (Decapoda: Palinuridae en la costa oeste de México

Directory of Open Access Journals (Sweden)

Raúl Pérez-González

2011-07-01

Full Text Available The lobster fishery in the Gulf of California and the south-central region of the western coast of Mexico consists of small-scale artisanal activity supported by Panulirus gracilis and P. inflatus, with an annual average catch of 132 ton. The present study analyzes the landing composition of this fishery and the population structure of P. gracilis. Carapace lengths (CL for this species ranged from 35 to 125 mm, and the most frequent sizes were between 60 and 85 mm. The size distribution was approximately normal. This implies that the fishery is composed of several size classes, with annual recruitment to the fishing areas. For the 1989-1990 and 1990-1991 fishing seasons, the mean monthly sizes of males were between 70.18 ± 11.74 and 81.11 ± 6.76 mm CL, whereas females averaged from 73.60 ± 8.95 to 80.28 ± 7.53 mm CL. Power-law relationships between carapace length (CL in mm and total weight (TW in g were determined, resulting in the following equations: PT = 0.0021 CL27689 for males and PT = 0.0009 CL³ 0038 for females. During certain periods of the year, males dominated the catch; however, the overall annual male:female ratio was near 1:1.La pesquería de langosta en el golfo de California y en el centro-sur de la costa occidental de México es una actividad artesanal a pequeña escala y es sostenida por Panulirus gracilis y P. inflatus, con una captura promedio anual de 132 ton. En este estudio se analiza la composición de los desembarques de esta pesquería y la estructura de la población de P. gracilis. El intervalo de talla de esta especie fue de 35 a 125 mm de longitud del cefalotórax (LC y el más frecuente se encontró entre 60 y 85 mm. La distribución de tallas fue aproximadamente normal. Esto implica que la pesquería está compuesta por varias clases de tallas, con un reclutamiento anual a las áreas de pesca. La talla media mensual de machos fue entre 70,18 ± 11,74 y 81,11 ± 6,76 mm LC y en hembras de 73,60 ± 8,95 a 80

Effective harvesting of the microalgae Chlorella protothecoides via bioflocculation with cationic starch

DEFF Research Database (Denmark)

Letelier Gordo, Carlos Octavio; Holdt, Susan Løvstad; De Francisci, Davide

2014-01-01

In the present work, the flocculation efficiency of cationic starch (Greenfloc 120) was tested on the fresh water microalga Chlorella protothecoides under different conditions (pH and flocculant concentrations). Different concentrations of Greenfloc 120 (0, 2.5, 5, 10, 20, 40mgL-1) were screened...... to use, efficient and cost-effective flocculant for harvesting of microalgae....

A Verhulst model for microalgae Botryococcus sp. growth and nutrient removal in wastewater

Science.gov (United States)

Jamaian, Siti Suhana; Bakeri, Noorhadila Mohd; Sunar, Norshuhaila Mohamed; Gani, Paran

2017-08-01

Microalgae Botryococcus sp. is a colonial green alga found in lakes and reservoirs in Malaysia. Previous studies reported that the potential of Botryococcus sp. photosynthesis as a source of fuel. The Botryococcus sp. contains hydrocarbon up to 75% of dry weight, which can be converted into petrol, diesel or turbine fuel or other liquid or gaseous hydrocarbons. Recently, an experimental study was conducted on phycoremediation technology for wastewater using Botryococcus sp. The phycoremediation technology is useful to remove the excess of nutrients such as nitrogen, phosphorus and also have the ability to remove various pollutants from wastewater. This research implements the Verhulst model to estimate the nutrient removal by microalgae Botryococcus sp. from the wastewater. This model has been validated with the experiments of microalgae Botryococcus sp. grown in domestic and palm oil wastewater. The results suggested that microalgae Botryococcus sp. could be cultured in domestic and palm oil wastewater while nutrients are reduced from these wastewaters.

Co-digestion of cultivated microalgae and sewage sludge from municipal waste water treatment.

Science.gov (United States)

Olsson, Jesper; Feng, Xin Mei; Ascue, Johnny; Gentili, Francesco G; Shabiimam, M A; Nehrenheim, Emma; Thorin, Eva

2014-11-01

In this study two wet microalgae cultures and one dried microalgae culture were co-digested in different proportions with sewage sludge in mesophilic and thermophilic conditions. The aim was to evaluate if the co-digestion could lead to an increased efficiency of methane production compared to digestion of sewage sludge alone. The results showed that co-digestion with both wet and dried microalgae, in certain proportions, increased the biochemical methane potential (BMP) compared with digestion of sewage sludge alone in mesophilic conditions. The BMP was significantly higher than the calculated BMP in many of the mixtures. This synergetic effect was statistically significant in a mixture containing 63% (w/w VS based) undigested sewage sludge and 37% (w/w VS based) wet algae slurry, which produced 23% more methane than observed with undigested sewage sludge alone. The trend was that thermophilic co-digestion of microalgae and undigested sewage sludge did not give the same synergy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microalgae dewatering based on forward osmosis employing proton exchange membrane.

Science.gov (United States)

Son, Jieun; Sung, Mina; Ryu, Hoyoung; Oh, You-Kwan; Han, Jong-In

2017-11-01

In this study, electrically-facilitated forward osmosis (FO) employing proton exchange membrane (PEM) was established for the purpose of microalgae dewatering. An increase in water flux was observed when an external voltage was applied to the FO equipped with the PEM; as expected, the trend became more dramatic with both concentration of draw solution and applied voltage raised. With this FO used for microalgae dewatering, 247% of increase in flux and 86% in final biomass concentration were observed. In addition to the effect on flux improvement, the electrically-facilitated FO exhibited the ability to remove chlorophyll from the dewatered biomass, down to 0.021±0015mg/g cell. All these suggest that the newly suggested electrically-facilitated FO, one particularly employed PEM, can indeed offer a workable way of dewatering of microalgae; it appeared to be so because it can also remove the ever-problematic chlorophyll from extracted lipids in a simultaneous fashion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biodiesel production from microalgae: cultivation parameters that affect lipid production

International Nuclear Information System (INIS)

Arias Penaranda, Martha Trinidad; Martinez Roldan, Alfredo de Jesus; Canizares Villanueva, Rosa Olivia

2013-01-01

The microalgae have the capacity to mitigate CO 2 emissions and to produce lipids, which are considered with potential to obtain third-generation biofuel. This review provides updated information of the influence of culture conditions on the lipids production with high productivity and profile suitable for the biodiesel production. This document presents a compilation of research conclusions over the last 13 years around the world. in the literature consulted, the authors conclude that although the behavior of microalgae at physiological stress conditions, varies between species; the nutrients limitation, especially nitrogen and phosphorus, associated with heterotrophic growth or high irradiances in phototrophy are considered the most efficient strategies to increase the lipid content in microalgae, particularly triglycerides (consisting of saturated and monounsaturated fatty acids), which are excellent for the production of biodiesel. Also, it is reported that the lipid content increase and the number of unsaturated fatty acids decrease with the addition of small amounts of CO 2 and harvesting the biomass it the stationary phase of growth.

Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds.

Science.gov (United States)

Poojary, Mahesha M; Barba, Francisco J; Aliakbarian, Bahar; Donsì, Francesco; Pataro, Gianpiero; Dias, Daniel A; Juliano, Pablo

2016-11-22

Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability.

Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds

Science.gov (United States)

Poojary, Mahesha M.; Barba, Francisco J.; Aliakbarian, Bahar; Donsì, Francesco; Pataro, Gianpiero; Dias, Daniel A.; Juliano, Pablo

2016-01-01

Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability. PMID:27879659

Discoloration of wastewater from a paint industry by the microalgae Chlorella sp

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Edgardo Angulo M

2017-09-01

Full Text Available Objective. Decoloring wastewater from a paint factory making use of Chlorella sp., microalgae as a biological way of treatment. Materials and methods. Samples of this microalgae previously cultivated with nourishing fertilizer under photoperiods of light and darkness were taken to test the microalgae Chlorella sp., initial concentration effect in the bioremoval process. For this purpose, it was cultivated in 0.10, 0.20 and 0.30 units of absorbance in bioreactors with 200 mL wastewater with and without nutrients. The biotest with the best rate of colour removal was chosen and the DBO5 and DQO were marked out. The immobilized Chlorella sp., in kappa carrageenan was also tested. Results. In the tests colour decrease percentage were 81.7, 69.7 and 58.3% without nutrients in the initial concentrations of 0.10, 0.20 and 0.30 units of absorbance respectively and 72.6, 69.0 and 86.8% for 0.10, 0.20 and 0.30 units of absorbance with nutrients respectively in the day of maximum growth. The immobilized microalgae score were 72.60% and 78.36% of color removal for 0.4 and 1.6 units of absorbance respectively. The higher colour removal test score was that with nutrients at 0.30 units of absorbance with several changes in DBO5 and DQO values. Conclusion. The biological wastewater treatment making use of Chlorella sp., microalgae can be considered as an effective choice in decolorating wastewater.

Arthroscopic intra- and extra-articular anterior cruciate ligament reconstruction with gracilis and semitendinosus tendons: a review

OpenAIRE

Marcacci, Maurilio; Zaffagnini, Stefano; Marcheggiani Muccioli, Giulio Maria; Neri, Maria Pia; Bondi, Alice; Nitri, Marco; Bonanzinga, Tommaso; Grassi, Alberto

2011-01-01

The purposes of this paper are to summarize the concepts relating to the use of a combined intra-articular and extra-articular reconstructive procedure in the arthroscopic treatment of a torn ACL and to review several operative techniques utilizing gracilis and semitendinosus tendons that are currently in use to treat this instability. The highly satisfactory results obtained over the time show that a combination of intra- and extra-articular procedures for ACL reconstruction is a valid surgi...

Strategies for Lipid Production Improvement in Microalgae as a Biodiesel Feedstock

Directory of Open Access Journals (Sweden)

L. D. Zhu

2016-01-01

Full Text Available In response to the energy crisis, global warming, and climate changes, microalgae have received a great deal of attention as a biofuel feedstock. Due to a high lipid content in microalgal cells, microalgae present as a promising alternative source for the production of biodiesel. Environmental and culturing condition variations can alter lipid production as well as chemical compositions of microalgae. Therefore, application of the strategies to activate lipid accumulation opens the door for lipid overproduction in microalgae. Until now, many original studies regarding the approaches for enhanced microalgal lipid production have been reported in an effort to push forward the production of microalgal biodiesel. However, the current literature demonstrates fragmented information available regarding the strategies for lipid production improvement. From the systematic point of view, the review highlights the main approaches for microalgal lipid accumulation induction to expedite the application of microalgal biodiesel as an alternative to fossil diesel for sustainable environment. Of the several strategies discussed, the one that is most commonly applied is the design of nutrient (e.g., nitrogen, phosphorus, and sulfur starvation or limitation. Other viable approaches such as light intensity, temperature, carbon dioxide, salinity stress, and metal influence can also achieve enhanced microalgal lipid production.

Effect of Metals, Metalloids and Metallic Nanoparticles on Microalgae Growth and Industrial Product Biosynthesis: A Review.

Science.gov (United States)

Miazek, Krystian; Iwanek, Waldemar; Remacle, Claire; Richel, Aurore; Goffin, Dorothee

2015-10-09

Microalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lipids, exopolymers, peptides, phytohormones, arsenoorganics, nanoparticles) from microalgae cultures upon exposure to various metals, is evaluated. Additionally, different methods to alter microalgae response towards metals and metal stress are described. Finally, possibilities to sustain high growth rates and productivity of microalgal cultures in the presence of metals are discussed.

Bioprocess engineering of microalgae to produce a variety of consumer products

Energy Technology Data Exchange (ETDEWEB)

Harun, Razif [Bio Engineering Laboratory (BEL), Department of Chemical Engineering, Monash University, Victoria 3800 (Australia); Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, 43400 Serdang (Malaysia); Singh, Manjinder; Forde, Gareth M.; Danquah, Michael K. [Bio Engineering Laboratory (BEL), Department of Chemical Engineering, Monash University, Victoria 3800 (Australia)

2010-04-15

Microalgae biotechnology has recently emerged into the lime light owing to numerous consumer products that can be harnessed from microalgae. Product portfolio stretches from straightforward biomass production for food and animal feed to valuable products extracted from microalgal biomass, including triglycerides which can be converted into biodiesel. For most of these applications, the production process is moderately economically viable and the market is developing. Considering the enormous biodiversity of microalgae and recent developments in genetic and metabolic engineering, this group of organisms represents one of the most promising sources for new products and applications. With the development of detailed culture and screening techniques, microalgal biotechnology can meet the high demands of food, energy and pharmaceutical industries. This review article discusses the technology and production platforms for development and creation of different valuable consumer products from microalgal biomass. (author)

Bioprocess engineering of microalgae to produce a variety of consumer products

International Nuclear Information System (INIS)

Harun, Razif; Singh, Manjinder; Forde, Gareth M.; Danquah, Michael K.

2010-01-01

Microalgae biotechnology has recently emerged into the lime light owing to numerous consumer products that can be harnessed from microalgae. Product portfolio stretches from straightforward biomass production for food and animal feed to valuable products extracted from microalgal biomass, including triglycerides which can be converted into biodiesel. For most of these applications, the production process is moderately economically viable and the market is developing. Considering the enormous biodiversity of microalgae and recent developments in genetic and metabolic engineering, this group of organisms represents one of the most promising sources for new products and applications. With the development of detailed culture and screening techniques, microalgal biotechnology can meet the high demands of food, energy and pharmaceutical industries. This review article discusses the technology and production platforms for development and creation of different valuable consumer products from microalgal biomass. (author)

Clinical and radiological outcomes after a quasi-anatomical reconstruction of medial patellofemoral ligament with gracilis tendon autograft.

Science.gov (United States)

Monllau, Joan C; Masferrer-Pino, Àngel; Ginovart, Gerard; Pérez-Prieto, Daniel; Gelber, Pablo E; Sanchis-Alfonso, Vicente

2017-08-01

To analyse the clinical and radiological outcomes of a quasi-anatomical reconstruction of the medial patellofemoral ligament (MPFL) with a gracilis tendon autograft. Patients with objective recurrent patellar instability that were operated on from 2006 to 2012 were included. A quasi-anatomical surgical technique was performed using a gracilis tendon autograft. It was anatomically attached at the patella, and the adductor magnus tendon was also used as a pulley for femoral fixation (non-anatomical reconstruction). The IKDC, Kujala and Lysholm scores as well as Tegner and VAS for pain were collected preoperatively and at final follow-up. Radiographic measurements of patellar position tilt and signs of osteoarthritis (OA) as well as trochlear dysplasia were also recorded. Thirty-six patients were included. The mean age at surgery was 25.6 years. After a minimum 27 months of follow-up, all functional scores significantly improved (p patellofemoral surfaces at the short term, as shown by the absence of radiological signs of OA in the CT scan. The procedure has been shown to be safe and suitable for the treatment of chronic patellar instability, including in adolescents with open physis. A new effective, inexpensive and easy-to-perform technique is described to reconstruct MPFL in the daily clinical practice. Therapeutic case series, Level IV.

Successful large-scale hatchery culture of sandfish (Holothuria scabra using micro-algae concentrates as a larval food source

Directory of Open Access Journals (Sweden)

Thane A. Militz

2018-02-01

Full Text Available This paper reports methodology for large-scale hatchery culture of sandfish, Holothuria scabra, in the absence of live, cultured micro-algae. We demonstrate how commercially-available micro-algae concentrates can be incorporated into hatchery protocols as the sole larval food source to completely replace live, cultured micro-algae. Micro-algae concentrates supported comparable hatchery production of sandfish to that of live, cultured micro-algae traditionally used in large-scale hatchery culture. The hatchery protocol presented allowed a single technician to achieve production of more than 18,800 juvenile sandfish at 40 days post-fertilisation in a low-resource hatchery in Papua New Guinea. Growth of auricularia larvae fed micro-algae concentrates was represented by the equation length (μm = 307.8 × ln(day + 209.2 (R2 = 0.93 while survival over the entire 40 day hatchery cycle was described by the equation survival = 2 × day−1.06 (R2 = 0.74. These results show that micro-algae concentrates have great potential for simplifying hatchery culture of sea cucumbers by reducing infrastructural and technical resources required for live micro-algae culture. The hatchery methodology described in this study is likely to have applicability to low-resource hatcheries throughout the Indo-Pacific and could support regional expansion of sandfish hatchery production.

Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

Science.gov (United States)

Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

2016-05-01

Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recent Developments on Genetic Engineering of Microalgae for Biofuels and Bio-Based Chemicals.

Science.gov (United States)

Ng, I-Son; Tan, Shih-I; Kao, Pei-Hsun; Chang, Yu-Kaung; Chang, Jo-Shu

2017-10-01

Microalgae serve as a promising source for the production of biofuels and bio-based chemicals. They are superior to terrestrial plants as feedstock in many aspects and their biomass is naturally rich in lipids, carbohydrates, proteins, pigments, and other valuable compounds. Due to the relatively slow growth rate and high cultivation cost of microalgae, to screen efficient and robust microalgal strains as well as genetic modifications of the available strains for further improvement are of urgent demand in the development of microalgae-based biorefinery. In genetic engineering of microalgae, transformation and selection methods are the key steps to accomplish the target gene modification. However, determination of the preferable type and dosage of antibiotics used for transformant selection is usually time-consuming and microalgal-strain-dependent. Therefore, more powerful and efficient techniques should be developed to meet this need. In this review, the conventional and emerging genome-editing tools (e.g., CRISPR-Cas9, TALEN, and ZFN) used in editing the genomes of nuclear, mitochondria, and chloroplast of microalgae are thoroughly surveyed. Although all the techniques mentioned above demonstrate their abilities to perform gene editing and desired phenotype screening, there still need to overcome higher production cost and lower biomass productivity, to achieve efficient production of the desired products in microalgal biorefineries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study of Selecting on Light Source Used for Micro-algae Cultivation in Space

Science.gov (United States)

Ai, Weidang; Ai, Weidang; Guo, Shuang-Sheng; Gao, Feng; Tang, Yong-Kang; Qin, Li-Feng

To select suitable light source for micro-algae cultivation in future space station, the selected Spirulina plastensis(No.7) were cultured under different lightening qualities, including six light sources that were made up of different combinations of red and blue light-emitting diode(LED). The growth, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the experiments, the red light may promote the cumulation of biomass of the Spirulina, and the cumulating rate was the highest under all red light source, but the syntheses of protein, phycobiliprotein, β-carotene, VE and other nutrients needs a certain portion of blue light; yet, the complete blue light condition is not favorable to the growth of Spirulina, and may bring pollution by chlorella and other kinds of micro-algae. It is concluded that the LEDs can be used as the light resource of micro-algae cultivation. The normal growth and development of microalgae need two light sources of both red and blue LEDs. The comprehensive analyses of the various factors that affect the growth of Spirulina, such as nutrition quality and photosynthetic activities, etc., showed that the combination of 80% red and 20% blue LED is the optimum one among those tested combinations. Key word: light-emitting diode; micro-algae; controlled ecological life support system (CELSS); space cultivation

hydroprocessing processing processing microalgae derived h

African Journals Online (AJOL)

eobe

higher yield of fuel per unit microalgae than the other ... used for the bio-crude production, it is not mandatory ... convert the whole biomass into primarily liquid .... Typical catalysts reportedly used for hydroprocessing ... design and economics for the conversion of whole ... separate reactors or a two-in-one reactor with a.

A geographical assessment of vegetation carbon stocks and greenhouse gas emissions on potential microalgae-based biofuel facilities in the United States.

Science.gov (United States)

Quiroz Arita, Carlos; Yilmaz, Özge; Barlak, Semin; Catton, Kimberly B; Quinn, Jason C; Bradley, Thomas H

2016-12-01

The microalgae biofuels life cycle assessments (LCA) present in the literature have excluded the effects of direct land use change (DLUC) from facility construction under the assumption that DLUC effects are negligible. This study seeks to model the greenhouse gas (GHG) emissions of microalgae biofuels including DLUC by quantifying the CO 2 equivalence of carbon released to the atmosphere through the construction of microalgae facilities. The locations and types of biomass and Soil Organic Carbon that are disturbed through microalgae cultivation facility construction are quantified using geographical models of microalgae productivity potential including consideration of land availability. The results of this study demonstrate that previous LCA of microalgae to biofuel processes have overestimated GHG benefits of microalgae-based biofuels production by failing to include the effect of DLUC. Previous estimations of microalgae biofuel production potential have correspondingly overestimated the volume of biofuels that can be produced in compliance with U.S. environmental goals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Eupafolin and Ethyl Acetate Fraction of Kalanchoe gracilis Stem Extract Show Potent Antiviral Activities against Enterovirus 71 and Coxsackievirus A16

Science.gov (United States)

Wang, Ching-Ying; Huang, Shun-Chueh; Lai, Zhen-Rung; Ho, Yu-Ling; Jou, Yu-Jen; Kung, Szu-Hao; Zhang, Yongjun; Chang, Yuan-Shiun; Lin, Cheng-Wen

2013-01-01

Enterovirus 71 (EV71) and coxsackievirus A16 (CoxA16) are main pathogens of hand-foot-and-mouth disease, occasionally causing aseptic meningitis and encephalitis in tropical and subtropical regions. Kalanchoe gracilis, Da-Huan-Hun, is a Chinese folk medicine for treating pain and inflammation, exhibiting antioxidant and anti-inflammatory activities. Our prior report (2012) cited K. gracilis leaf extract as moderately active against EV71 and CoxA16. This study further rates antienteroviral potential of K. gracilis stem (KGS) extract to identify potent antiviral fractions and components. The extract moderately inhibits viral cytopathicity and virus yield, as well as in vitro replication of EV71 (IC50 = 75.18 μg/mL) and CoxA16 (IC50 = 81.41 μg/mL). Ethyl acetate (EA) fraction of KGS extract showed greater antiviral activity than that of n-butanol or aqueous fraction: IC50 values of 4.21 μg/mL against EV71 and 9.08 μg/mL against CoxA16. HPLC analysis, UV-Vis absorption spectroscopy, and plaque reduction assay indicate that eupafolin is a vital component of EA fraction showing potent activity against EV71 (IC50 = 1.39 μM) and CoxA16 (IC50 = 5.24 μM). Eupafolin specifically lessened virus-induced upregulation of IL-6 and RANTES by inhibiting virus-induced ERK1/2, AP-1, and STAT3 signals. Anti-enteroviral potency of KGS EA fraction and eupafolin shows the clinical potential against EV71 and CoxA16 infection. PMID:24078828

Eupafolin and Ethyl Acetate Fraction of Kalanchoe gracilis Stem Extract Show Potent Antiviral Activities against Enterovirus 71 and Coxsackievirus A16

Directory of Open Access Journals (Sweden)

Ching-Ying Wang

2013-01-01

Full Text Available Enterovirus 71 (EV71 and coxsackievirus A16 (CoxA16 are main pathogens of hand-foot-and-mouth disease, occasionally causing aseptic meningitis and encephalitis in tropical and subtropical regions. Kalanchoe gracilis, Da-Huan-Hun, is a Chinese folk medicine for treating pain and inflammation, exhibiting antioxidant and anti-inflammatory activities. Our prior report (2012 cited K. gracilis leaf extract as moderately active against EV71 and CoxA16. This study further rates antienteroviral potential of K. gracilis stem (KGS extract to identify potent antiviral fractions and components. The extract moderately inhibits viral cytopathicity and virus yield, as well as in vitro replication of EV71 (IC50 = 75.18 μg/mL and CoxA16 (IC50 = 81.41 μg/mL. Ethyl acetate (EA fraction of KGS extract showed greater antiviral activity than that of n-butanol or aqueous fraction: IC50 values of 4.21 μg/mL against EV71 and 9.08 μg/mL against CoxA16. HPLC analysis, UV-Vis absorption spectroscopy, and plaque reduction assay indicate that eupafolin is a vital component of EA fraction showing potent activity against EV71 (IC50 = 1.39 μM and CoxA16 (IC50 = 5.24 μM. Eupafolin specifically lessened virus-induced upregulation of IL-6 and RANTES by inhibiting virus-induced ERK1/2, AP-1, and STAT3 signals. Anti-enteroviral potency of KGS EA fraction and eupafolin shows the clinical potential against EV71 and CoxA16 infection.

Optimal design of microalgae-based biorefinery: Economics, opportunities and challenges

DEFF Research Database (Denmark)

Rizwan, Muhammad; Lee, Jay H.; Gani, Rafiqul

2015-01-01

Microalgae have great potential as a feedstock for the production of a wide range of end-products under the broad concept of biorefinery. In an earlier work, we proposed a superstructure based optimization model to find the optimal processing pathway for the production of biodiesel from microalgal...... biomass, and identified several challenges with the focus being on utilizing lipids extracted microalgal biomass for economic and environmentally friendly production of useful energy products. In this paper, we expand the previous optimization framework by considering the processing of microalgae residue...

Improving biogas production from microalgae by enzymatic pretreatment.

Science.gov (United States)

Passos, Fabiana; Hom-Diaz, Andrea; Blanquez, Paqui; Vicent, Teresa; Ferrer, Ivet

2016-01-01

In this study, enzymatic pretreatment of microalgal biomass was investigated under different conditions and evaluated using biochemical methane potential (BMP) tests. Cellulase, glucohydrolase and an enzyme mix composed of cellulase, glucohydrolase and xylanase were selected based on the microalgae cell wall composition (cellulose, hemicellulose, pectin and glycoprotein). All of them increased organic matter solubilisation, obtaining high values already after 6h of pretreatment with an enzyme dose of 1% for cellulase and the enzyme mix. BMP tests with pretreated microalgae showed a methane yield increase of 8 and 15% for cellulase and the enzyme mix, respectively. Prospective research should evaluate enzymatic pretreatments in continuous anaerobic reactors so as to estimate the energy balance and economic cost of the process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Metals, Metalloids and Metallic Nanoparticles on Microalgae Growth and Industrial Product Biosynthesis: A Review

Science.gov (United States)

Miazek, Krystian; Iwanek, Waldemar; Remacle, Claire; Richel, Aurore; Goffin, Dorothee

2015-01-01

Microalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lipids, exopolymers, peptides, phytohormones, arsenoorganics, nanoparticles) from microalgae cultures upon exposure to various metals, is evaluated. Additionally, different methods to alter microalgae response towards metals and metal stress are described. Finally, possibilities to sustain high growth rates and productivity of microalgal cultures in the presence of metals are discussed. PMID:26473834

Effect of Metals, Metalloids and Metallic Nanoparticles on Microalgae Growth and Industrial Product Biosynthesis: A Review

Directory of Open Access Journals (Sweden)

Krystian Miazek

2015-10-01

Full Text Available Microalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lipids, exopolymers, peptides, phytohormones, arsenoorganics, nanoparticles from microalgae cultures upon exposure to various metals, is evaluated. Additionally, different methods to alter microalgae response towards metals and metal stress are described. Finally, possibilities to sustain high growth rates and productivity of microalgal cultures in the presence of metals are discussed.

The Effects of Audible Sound for Enhancing the Growth Rate of Microalgae Haematococcus pluvialis in Vegetative Stage

Directory of Open Access Journals (Sweden)

Marcelinus Christwardana

2017-07-01

Full Text Available Physico-stimulant like audible sound is one of the new promising methods for enhancing microalgae growth rate. Here, microalgae Haematococcus pluvialis was cultivated with the addition of audible sound with titles “Blues for Elle” and “Far and Wide.” The objective of this research was to evaluate the effect of audible sound to the growth and productivity of microalgae. The experiment has been conducted by exposing the audible sound for 8 h in 22 days to microalgae cultivation. The result showed that microalgae H. pluvialis treated by the music “Blues for Elle” shows the highest growth rate (0.03 per day, and 58% higher than the one without audible sound. The average number of cells in stationary phase is 0.76 × 104 cells/mL culture and the productivity is 3.467 × 102 cells/mL/day. The pH of microalgae medium slightly decreases because of proton production during photosynthesis process. The kinetic rate constant (kapp is 0.078 per day, reaction half-life (t1/2 is 8.89 days, and catalytic surface (Ksurf is 1.66 × 10−5/day/cm2. In conclusion, this audible sound is very useful to stimulate microalgae growth rate, especially H. pluvialis.

The Costs of Producing Biodiesel from Microalgae in the Asia-Pacific Region

Directory of Open Access Journals (Sweden)

G.J. Griffin

2013-10-01

Full Text Available Capital and operating cost estimates for converting microalgae to oil or biodiesel are compared. These cost comparisons are based on Australian locations, which are expected to fall at the lower end of the cost spectrum in the Asia-Pacific Region and other parts of the world.  It is assumed that microalgae are grown in a concentrated saltwater medium in raceway ponds, then are harvested, dewatered and the oil is extracted and converted to biodiesel by transesterification. The size of the desired pond system affects the number of potential locations due to constraints in resource availability. Cost estimates vary significantly due to differences in the assumed oil productivity, the harvesting equipment and the method of converting residual biomass to electric power. A comparison is made with recent cost estimates from other parts of the world, in which the expected costs of microalgae oil production from a number of publicly available sources lay between 0.34–31.0 USD/L.  The resulting cost estimates of between 1.37—2.66 USD/L are at the lower end of this scale, thereby confirming that Australia has the potential to be a low-cost producer of algal oil and biodiesel in the Asia-Pacific Region.  It was significant that, despite similar assumptions for the microalgae-to-oil process, cost estimates for the final biodiesel or oil price differed by a factor of 2.  This highlights the high degree of uncertainty in such economic predictions. Keywords: Asia-Pacific region; biodiesel; economics; microalgaeThis article is cited as :Griffin, G., Batten, D., Beer, T., & Campbell, P. (2013. The Costs of Producing Biodiesel from Microalgae in the Asia-Pacific Region. International Journal Of Renewable Energy Development (IJRED, 2(3, 105-113. doi:10.14710/ijred.2.3.105-113Permalinkhttp://dx.doi.org/10.14710/ijred.2.3.105-113

Use of microalgae to recycle nutrients in aqueous phase derived from hydrothermal liquefaction process.

Science.gov (United States)

Leng, Lijian; Li, Jun; Wen, Zhiyou; Zhou, Wenguang

2018-05-01

Hydrothermal liquefaction (HTL) of microalgae biomass generates an aqueous phase (AP) byproduct with limited energy value. Recycling the AP solution as a source of nutrients for microalgae cultivation provides an opportunity for a cost-effective production of HTL based biofuel and algal biomass feedstock for HTL, allowing a closed-loop biofuel production in microalgae HTL biofuel system. This paper aims to provide a comprehensive overview of characteristics of AP and its nutrients recycling for algae production. Inhibitory effects resulted from the toxic compounds in AP and alleviation strategies are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

RECOVERY AND SEQUESTRATION OF CO2 FROM STATIONARY COMBUSTION SYSTEMS BY PHOTOSYNTHESIS OF MICROALGAE

Energy Technology Data Exchange (ETDEWEB)

Dr. T. Nakamura; Dr. Miguel Olaizola; Dr. Stephen M. Masutani

2002-12-01

Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 July to 30 September 2002 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work conducted during the previous reporting period, PSI initiated work on feasibility demonstration of direct feeding of coal combustion gas to microalgae. Aquasearch continued their effort on selection and characterization of microalgae suitable for CO{sub 2} sequestration. University of Hawaii continued effort on system optimization of the CO{sub 2} sequestration system.

Microalgae Oil Production: A Downstream Approach to Energy Requirements for the Minamisoma Pilot Plant

Directory of Open Access Journals (Sweden)

Dhani S. Wibawa

2018-02-01

Full Text Available This study investigates the potential of microalgae oil production as an alternative renewable energy source, in a pilot project located at Minamisoma City in the Fukushima Prefecture of Japan. The algal communities used in this research were the locally mixed species, which were mainly composed of Desmodesmus collected from the Minamisoma pilot project. The microalgae oil-production processes in Minamisoma consisted of three stages: cultivation, dewatering, and extraction. The estimated theoretical input-energy requirement for extracting oil was 137.25 MJ to process 50 m3 of microalgae, which was divided into cultivation 15.40 MJ, centrifuge 13.39 MJ, drum filter 14.17 MJ, and hydrothermal liquefaction (HTL 94.29 MJ. The energy profit ratio (EPR was 1.41. The total energy requirement was highest in the HTL process (68% followed by cultivation (11% and the drum filter (10%. The EPR value increased along with the yield in the cultivation process. Using HTL, the microalgae biomass could be converted to bio-crude oil to increase the oil yield in the extraction process. Therefore, in the long run, the HTL process could help lower production costs, due to the lack of chemical additions, for extracting oil in the downstream estimation of the energy requirements for microalgae oil production.

RECOVERY AND SEQUESTRATION OF CO2 FROM STATIONARY COMBUSTION SYSTEMS BY PHOTOSYNTHESIS OF MICROALGAE

Energy Technology Data Exchange (ETDEWEB)

Dr. Takashi Nakamura

2003-04-01

Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 October to 31 December 2002 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work conducted during the previous reporting period, PSI initiated work on feasibility demonstration of direct feeding of coal combustion gas to microalgae. Aquasearch continued their effort on selection and characterization of microalgae suitable for CO{sub 2} sequestration. University of Hawaii continued effort on system optimization of the CO{sub 2} sequestration system.

Potentials of Microalgae Biodiesel Production in Nigeria

African Journals Online (AJOL)

Prof. Ogunji

production industries in Nigeria will have positive effects on socio-economic development ... Keywords: bio-energy; climatic conditions; fossil fuel; microalgae; production economics ... of affordable land and labour (Sielhorst et al., ..... by clouds. Closed photobioreactors are scarcely influenced by rainfall pattern; however, ...

Antenna size reduction in microalgae mass culture

NARCIS (Netherlands)

Mooij, de T.

2016-01-01

The thesis describes the potential of microalgae with a reduced light harvesting antenna for biomass production under mass culture conditions (high biomass density, high light intensity). Theoretically, the lower chlorophyll content reduces the light harvesting capacity and with that the amount

Optimization of Pre-Treatment Process Parameters to Generate Biodiesel from Microalga

Directory of Open Access Journals (Sweden)

Chukwuma Onumaegbu

2018-03-01

Full Text Available Cell disruption is an integral part of microalga production process, which improves the release of intracellular products that are essential for biofuel production. In this work, pre-treatment parameters that will enhance the efficiency of lipid production using high-pressure homogenizer on microalgae biomass will be investigated. The high-pressure homogenizer that is considered is a GYB40-10S/GY60-6S; with a pre-treatment pressure of 1000 psi, 2000 psi, and 3000 psi, the number of passes; 1, 2, and 3, a reaction time of 3, 3.5, and 4 h. Pressure and cavitation increase the efficiency of the pre-treatment process of the homogenizer. In addition, homogenization shear force and pressure are the basic significant factors that enhance the efficiency of microalgae cell rupture. Also, the use of modelling to simulate pre-treatment processes (Response Surface Methodology (RSM, Box-Behnken Designs (BBD, and design of experiment (DOE for process optimization will be adopted in this study. The results clearly demonstrate that high-pressure homogenization pre-treatment can effectively disrupt microalga cell walls to enhance lipid recovery efficiency, with a relatively short extraction time, both that are essential for maintaining a good quality of lipids for biofuel production. A maximum of 18% lipid yields were obtained after 3 h of HPH pre-treatment at 3000 psi.

Production of biodiesel from microalgae through biological carbon capture: a review.

Science.gov (United States)

Mondal, Madhumanti; Goswami, Shrayanti; Ghosh, Ashmita; Oinam, Gunapati; Tiwari, O N; Das, Papita; Gayen, K; Mandal, M K; Halder, G N

2017-06-01

Gradual increase in concentration of carbon dioxide (CO 2 ) in the atmosphere due to the various anthropogenic interventions leading to significant alteration in the global carbon cycle has been a subject of worldwide attention and matter of potential research over the last few decades. In these alarming scenario microalgae seems to be an attractive medium for capturing the excess CO 2 present in the atmosphere generated from different sources such as power plants, automobiles, volcanic eruption, decomposition of organic matters and forest fires. This captured CO 2 through microalgae could be used as potential carbon source to produce lipids for the generation of biofuel for replacing petroleum-derived transport fuel without affecting the supply of food and crops. This comprehensive review strives to provide a systematic account of recent developments in the field of biological carbon capture through microalgae for its utilization towards the generation of biodiesel highlighting the significance of certain key parameters such as selection of efficient strain, microalgal metabolism, cultivation systems (open and closed) and biomass production along with the national and international biodiesel specifications and properties. The potential use of photobioreactors for biodiesel production under the influence of various factors viz., light intensity, pH, time, temperature, CO 2 concentration and flow rate has been discussed. The review also provides an economic overview and future outlook on biodiesel production from microalgae.

Prospects of biodiesel production from microalgae in India

Energy Technology Data Exchange (ETDEWEB)

Khan, Shakeel A.; Hussain, Mir Z.; Prasad, S. [Division of Environmental Sciences, Indian Agricultural Research Institute, New Delhi 110012 (India); Rashmi; Banerjee, U.C. [Department of Pharmaceutical Technology (Biotechnology), National Institute of Pharmaceutical and Education Research (NIPER), Sector 67, Phase X, S.A.S. Nagar, Mohali 160062, Punjab (India)

2009-12-15

Energy is essential and vital for development, and the global economy literally runs on energy. The use of fossil fuels as energy is now widely accepted as unsustainable due to depleting resources and also due to the accumulation of greenhouse gases in the environment. Renewable and carbon neutral biodiesel are necessary for environmental and economic sustainability. Biodiesel demand is constantly increasing as the reservoir of fossil fuel are depleting. Unfortunately biodiesel produced from oil crop, waste cooking oil and animal fats are not able to replace fossil fuel. The viability of the first generation biofuels production is however questionable because of the conflict with food supply. Production of biodiesel using microalgae biomass appears to be a viable alternative. The oil productivity of many microalgae exceeds the best producing oil crops. Microalgae are photosynthetic microorganisms which convert sunlight, water and CO{sub 2} to sugars, from which macromolecules, such as lipids and triacylglycerols (TAGs) can be obtained. These TAGs are the promising and sustainable feedstock for biodiesel production. Microalgal biorefinery approach can be used to reduce the cost of making microalgal biodiesel. Microalgal-based carbon sequestration technologies cover the cost of carbon capture and sequestration. The present paper is an attempt to review the potential of microalgal biodiesel in comparison to the agricultural crops and its prospects in India. (author)

Algevir: An Expression System for Microalgae Based on Viral Vectors

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Bernardo Bañuelos-Hernández

2017-06-01

Full Text Available The use of recombinant algae for the production of valuable compounds is opening promising biotechnological applications. However, the development of efficient expression approaches is still needed to expand the exploitation of microalgae in biotechnology. Herein, the concept of using viral expression vectors in microalgae was explored for the first time. An inducible geminiviral vector leading to Rep-mediated replication of the expression cassette allowed the production of antigenic proteins at high levels. This system, called Algevir, allows the production of complex viral proteins (GP1 from Zaire ebolavirus and bacterial toxin subunits (B subunit of the heat-labile Escherichia coli enterotoxin, which retained their antigenic activity. The highest achieved yield was 1.25 mg/g fresh biomass (6 mg/L of culture, which was attained 3 days after transformation. The Algevir system allows for a fast and efficient production of recombinant proteins, overcoming the difficulties imposed by the low yields and unstable expression patterns frequently observed in stably transformed microalgae at the nuclear level; as well as the toxicity of some target proteins.

Algevir: An Expression System for Microalgae Based on Viral Vectors

Science.gov (United States)

Bañuelos-Hernández, Bernardo; Monreal-Escalante, Elizabeth; González-Ortega, Omar; Angulo, Carlos; Rosales-Mendoza, Sergio

2017-01-01

The use of recombinant algae for the production of valuable compounds is opening promising biotechnological applications. However, the development of efficient expression approaches is still needed to expand the exploitation of microalgae in biotechnology. Herein, the concept of using viral expression vectors in microalgae was explored for the first time. An inducible geminiviral vector leading to Rep-mediated replication of the expression cassette allowed the production of antigenic proteins at high levels. This system, called Algevir, allows the production of complex viral proteins (GP1 from Zaire ebolavirus) and bacterial toxin subunits (B subunit of the heat-labile Escherichia coli enterotoxin), which retained their antigenic activity. The highest achieved yield was 1.25 mg/g fresh biomass (6 mg/L of culture), which was attained 3 days after transformation. The Algevir system allows for a fast and efficient production of recombinant proteins, overcoming the difficulties imposed by the low yields and unstable expression patterns frequently observed in stably transformed microalgae at the nuclear level; as well as the toxicity of some target proteins. PMID:28713333

Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds

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Mahesha M. Poojary

2016-11-01

Full Text Available Marine microalgae and seaweeds (microalgae represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield, selectivity (purity, high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability.

Engineering the Chloroplast Genome of Oleaginous Marine Microalga Nannochloropsis oceanica

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Qinhua Gan

2018-04-01

Full Text Available Plastid engineering offers an important tool to fill the gap between the technical and the enormous potential of microalgal photosynthetic cell factory. However, to date, few reports on plastid engineering in industrial microalgae have been documented. This is largely due to the small cell sizes and complex cell-wall structures which make these species intractable to current plastid transformation methods (i.e., biolistic transformation and polyethylene glycol-mediated transformation. Here, employing the industrial oleaginous microalga Nannochloropsis oceanica as a model, an electroporation-mediated chloroplast transformation approach was established. Fluorescent microscopy and laser confocal scanning microscopy confirmed the expression of the green fluorescence protein, driven by the endogenous plastid promoter and terminator. Zeocin-resistance selection led to an acquisition of homoplasmic strains of which a stable and site-specific recombination within the chloroplast genome was revealed by sequencing and DNA gel blotting. This demonstration of electroporation-mediated chloroplast transformation opens many doors for plastid genome editing in industrial microalgae, particularly species of which the chloroplasts are recalcitrant to chemical and microparticle bombardment transformation.

Stabilisation of microalgae: Iodine mobilisation under aerobic and anaerobic conditions.

Science.gov (United States)

Han, Wei; Clarke, William; Pratt, Steven

2015-10-01

Mobilisation of iodine during microalgae stabilisation was investigated, with the view of assessing the potential of stabilised microalgae as an iodine-rich fertiliser. An iodine-rich waste microalgae (0.35 ± 0.05 mg I g(-1) VS(added)) was stabilised under aerobic and anaerobic conditions. Iodine mobilisation was linearly correlated with carbon emission, indicating iodine was in the form of organoiodine. Comparison between iodine and nitrogen mobilisation relative to carbon emission indicated that these elements were, at least in part, housed separately within the cells. After stabilisation, there were 0.22 ± 0.05 and 0.19 ± 0.01 mg g(-1) VS(added) iodine remaining in the solid in the aerobic and anaerobic processed material respectively, meaning 38 ± 5.0% (aerobic) and 50 ± 8.6% (anaerobic) of the iodine were mobilised, and consequently lost from the material. The iodine content of the stabilised material is comparable to the iodine content of some seaweed fertilisers, and potentially satisfies an efficient I-fertilisation dose. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optic chiasm in the species of order Clupeiformes, family Clupeidae: optic chiasm of Spratelloides gracilis shows an opposite laterality to that of Etrumeus teres.

Science.gov (United States)

Mogi, Kazue; Misawa, Kazuya; Utsunomiya, Kentaro; Kawada, Yuta; Yamazaki, Toshihisa; Takeuchi, Shigeo; Toyoizumi, Ryuji

2009-09-01

In most teleost fishes, the optic nerves decussate completely as they project to the mesencephalic region. Examination of the decussation pattern of 25 species from 11 different orders in Pisces revealed that each species shows a specific chiasmic type. In 11 species out of the 25, laterality of the chiasmic pattern was not determined; in half of the individuals examined, the left optic nerve ran dorsally to the right optic nerve, while in the other half, the right optic nerve was dorsal. In eight other species the optic nerves from both eyes branched into several bundles at the chiasmic point, and intercalated to form a complicated decussation pattern. In the present study we report our findings that Spratelloides gracilis, of the order Clupeiformes, family Clupeidae, shows a particular laterality of decussation: the left optic nerve ran dorsally to the right (n=200/202). In contrast, Etrumeus teres, of the same order and family, had a strong preference of the opposite (complementary) chiasmic pattern to that of S. gracilis (n=59/59), revealing that these two species display opposite left-right optic chiasm patterning. As far as we investigated, other species of Clupeiformes have not shown left-right preference in the decussation pattern. We conclude that the opposite laterality of the optic chiasms of these two closely related species, S. gracilis and E. teres, enables investigation of species-specific laterality in fishes of symmetric shapes.

Modeling of the Kinetics of Supercritical Fluid Extraction of Lipids from Microalgae with Emphasis on Extract Desorption

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Helena Sovová

2016-05-01

Full Text Available Microalgae contain valuable biologically active lipophilic substances such as omega-3 fatty acids and carotenoids. In contrast to the recovery of vegetable oils from seeds, where the extraction with supercritical CO2 is used as a mild and selective method, economically viable application of this method on similarly soluble oils from microalgae requires, in most cases, much higher pressure. This paper presents and verifies hypothesis that this difference is caused by high adsorption capacity of microalgae. Under the pressures usually applied in supercritical fluid extraction from plants, microalgae bind a large fraction of the extracted oil, while under extremely high CO2 pressures their adsorption capacity diminishes and the extraction rate depends on oil solubility in supercritical CO2. A mathematical model for the extraction from microalgae was derived and applied to literature data on the extraction kinetics in order to determine model parameters.

Isolation of microalgae species from arid environments and ...

African Journals Online (AJOL)

Isolation of microalgae species from arid environments and evaluation of their potentials for biodiesel production. ... African Journal of Biotechnology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives.

Microalgae to biofuels: life cycle impacts of methane production of anaerobically digested lipid extracted algae.

Science.gov (United States)

Quinn, Jason C; Hanif, Asma; Sharvelle, Sybil; Bradley, Thomas H

2014-11-01

This study presents experimental measurements of the biochemical methane production for whole and lipid extracted Nannochloropsis salina. Results show whole microalgae produced 430 cm(3)-CH4 g-volatile solids(-1) (g-VS) (σ=60), 3 times more methane than was produced by the LEA, 140 cm(3)-CH4 g-VS(-1) (σ=30). Results illustrate current anaerobic modeling efforts in microalgae to biofuel assessments are not reflecting the impact of lipid removal. On a systems level, the overestimation of methane production is shown to positively skew the environmental impact of the microalgae to biofuels process. Discussion focuses on a comparison results to those of previous anaerobic digestion studies and quantifies the corresponding change in greenhouse gas emissions of the microalgae to biofuels process based on results from this study. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of gamma radiation and fast neutrons on the growth of Haplopappus gracilis (Nutt) A. Gray callus

International Nuclear Information System (INIS)

Cebulska-Wasilewska, A.; Wajda, L.; Korzonek, M.; Polska Akademia Nauk, Krakow. Inst. Fizjologii Roslin)

1979-01-01

The sensitivity of the callus of Haplopappus gracilis to gamma radiation and fast neutrons was studied. High doses of radiation cause inhibition of callus growth. At small doses the effect is less pronounced. Stimulation of callus growth was seen. Apart from morphological changes, ionizing radiations lowered the fresh weight ratio of the callus. The RBE value for 5.5 MeV neutrons depended on the dose rate of radiation and the combination of growth medium. (author)

Modulating effects of orally supplied Euglena gracilis on the physiological responses of the freshwater mussel Diplodon chilensis, exposed to sewage water pollution in a Patagonian river (Argentina).

Science.gov (United States)

Bianchi, Virginia A; Castro, Juan M; Rocchetta, Iara; Conforti, Visitación; Pascual, Mariano; Luquet, Carlos M

2016-04-01

In order to test if orally supplied Euglena sp. cells modulate the physiological status of bivalves during bioremediation procedures, we evaluated the effect of Euglena gracilis diet on the immune response, oxidative balance and metabolic condition of Diplodon chilensis exposed to sewage water pollution. Mussels were fed for 90 days with E. gracilis (EG) or Scenedesmus vacuolatus (SV, control diet), and then exposed for 10 days at three sites along the Pocahullo river basin: 1) an unpolluted site, upstream of the city (control, C); 2) upstream (UpS) and 3) downstream (DoS) from the main tertiary-treated sewage discharge, in the city of San Martín de los Andes, Northwest Patagonia, Argentina. Our results show that the total hemocyte number decreases while pollution load increases along the river course for both, EG and SV mussels. Phagocytic activity is higher in EG mussels than in SV ones under all conditions. Reactive oxygen species (ROS) production in hemocytes increases with the increase in the pollution load, being significantly higher for EG mussels than for SV ones at DoS; no changes are observed for total oxyradical scavenging capacity (TOSC). Hemocytes' viability is increased for E. gracilis diet at C and remains unchanged in this group of mussels when exposed at the polluted sites. Lysosomal membrane stability is higher in EG mussels than in SV ones for all conditions, although it is decreased at polluted sites compared with that at C. Antioxidant (catalase) and detoxifying (gluthatione S-transferase) defenses are generally lower in gills and digestive gland of EG mussels than in SV ones. Lipid peroxidation (TBARS) is evident in gills of EG mussels at C, and in digestive gland of the same group, at all the sites. Gill mass factor (GF) is affected by the E. gracilis diet; it is increased at C and decreased at polluted sites when compared with that of SV ones. Digestive gland mass factor (DGF) is higher in EG mussels than in SV ones. In D

Hydrothermal Liquefaction of the Microalgae Phaeodactylum tricornutum

DEFF Research Database (Denmark)

Sigaard Christensen, Per; Peng, Gaël; Vogel, Frédéric

2014-01-01

The microalgae Phaeodactylum tricornutum was processed by hydrothermal liquefaction in order to assess the influence of reaction temperature and reaction time on the product and elemental distribution. The experiments were carried out at different reaction times (5 and 15 min) and over a wide range...

Secondary wastewater treatment by microalgae isolated from ...

African Journals Online (AJOL)

Microalgae play a fundamental role in primary and secondary wastewater treatment. In this work the growth, photosynthetic activity and removal of phosphorus from wastewater effluents by indigenous blue-green algal species, Spirulina and Oscillatoria, isolated from Gaborone oxidation ponds was studied. Oscillatoria and ...

Scenario evaluation of open pond microalgae production

NARCIS (Netherlands)

Slegers, P.M.; Lösing, M.B.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

2013-01-01

To evaluate microalgae production in large scale open ponds under different climatologic conditions, a model-based framework is used to study the effect of light conditions, water temperature and reactor design on trends in algae productivity. Scenario analyses have been done for two algae species

A Novel Enclosed Online Control System for Microalgae Production

Directory of Open Access Journals (Sweden)

Bin Li

2014-03-01

Full Text Available Microalgae are single celled microscopic organisms which, like plants, convert solar energy into bio-energy through photosynthesis. They can be used to produce a variety of bio-based products, such as bio-food and biodiesel. Large scale algae production can be achieved in open or closed systems. An enclosed online microalgae control production system is presented in this paper. The designed system is composed of a reactor which is placed inside a box with light reflecting surface. Lighting system, CO2 supply, heating, as well as online cell mass monitoring via spectrophotometer, were integrated. The online monitoring of cell mass concentration is coupled to two pumps which remove a certain amount of cell suspension, and take fresh media as an alternative. Also, a LabView program was developed to collect data from a spectrophotometer and processed in a computer. Considering the limited experimental conditions and the pollution possibility for its high productivity if liquid is not properly disposed, food color was used to test the designed novel system in this paper. The results showed that, the system could detect a change in absorption over time with periodic sampling for every 4.8 minutes. When absorption value reach a pre-set gate, pump1 immediately starts to pump out a certain amount of solution?then pump2 starts to pump in fresh media according to the calculated time. The concentration could be controlled below the threshold value. From the continuous test using food color, the designed system showed good stability and controlling accuracy. It provides a good reference for the following microalgae testing experiment in future. Considering the applications of microalgae in agriculture, this research also provides resources for bio-fertilizer.

Spectral optical properties of selected photosynthetic microalgae producing biofuels

International Nuclear Information System (INIS)

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

2013-01-01

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

Combustion behavior and kinetics of low-lipid microalgae via thermogravimetric analysis.

Science.gov (United States)

Gai, Chao; Liu, Zhengang; Han, Guanghua; Peng, Nana; Fan, Aonan

2015-04-01

Thermogravimetric analysis and differential thermal analysis were employed to investigate combustion characteristics of two low-lipid microalgae, Chlorella pyrenoidosa (CP) and Spirulina platensis (SP) and iso-conversional Starink approach was used to calculate the kinetic parameters in the present study. The results showed that three stages of mass loss, including dehydration, devolatilization and char oxidation, were observed during combustion of both of two low-lipid microalgae. The whole weight loss of combustion of two microalgae was both shifted to higher temperature zones with increased heating rates from 10 to 40 K/min. In the 0.1-0.9 conversion range, the apparent activation energy of CP increased first from 51.96 to 79.53 kJ/mol, then decreased to 55.59 kJ/mol. Finally, it slightly increased to 67.27 kJ/mol. In the case of SP, the apparent activation energy gradually increased from 68.51 to 91.06 kJ/mol. Copyright © 2015 Elsevier Ltd. All rights reserved.

Combined Extraction Processes of Lipid from Chlorella vulgaris Microalgae: Microwave Prior to Supercritical Carbon Dioxide Extraction

Science.gov (United States)

Dejoye, Céline; Vian, Maryline Abert; Lumia, Guy; Bouscarle, Christian; Charton, Frederic; Chemat, Farid

2011-01-01

Extraction yields and fatty acid profiles from freeze-dried Chlorella vulgaris by microwave pretreatment followed by supercritical carbon dioxide (MW-SCCO2) extraction were compared with those obtained by supercritical carbon dioxide extraction alone (SCCO2). Work performed with pressure range of 20–28 Mpa and temperature interval of 40–70 °C, gave the highest extraction yield (w/w dry weight) at 28 MPa/40 °C. MW-SCCO2 allowed to obtain the highest extraction yield (4.73%) compared to SCCO2 extraction alone (1.81%). Qualitative and quantitative analyses of microalgae oil showed that palmitic, oleic, linoleic and α-linolenic acid were the most abundant identified fatty acids. Oils obtained by MW-SCCO2 extraction had the highest concentrations of fatty acids compared to SCCO2 extraction without pretreatment. Native form, and microwave pretreated and untreated microalgae were observed by scanning electronic microscopy (SEM). SEM micrographs of pretreated microalgae present tearing wall agglomerates. After SCCO2, microwave pretreated microalgae presented several micro cracks; while native form microalgae wall was slightly damaged. PMID:22272135

Combined Extraction Processes of Lipid from Chlorella vulgaris Microalgae: Microwave Prior to Supercritical Carbon Dioxide Extraction

Directory of Open Access Journals (Sweden)

Farid Chemat

2011-12-01

Full Text Available Extraction yields and fatty acid profiles from freeze-dried Chlorella vulgaris by microwave pretreatment followed by supercritical carbon dioxide (MW-SCCO2 extraction were compared with those obtained by supercritical carbon dioxide extraction alone (SCCO2. Work performed with pressure range of 20–28 Mpa and temperature interval of 40–70 °C, gave the highest extraction yield (w/w dry weight at 28 MPa/40 °C. MW-SCCO2 allowed to obtain the highest extraction yield (4.73% compared to SCCO2 extraction alone (1.81%. Qualitative and quantitative analyses of microalgae oil showed that palmitic, oleic, linoleic and α-linolenic acid were the most abundant identified fatty acids. Oils obtained by MW-SCCO2 extraction had the highest concentrations of fatty acids compared to SCCO2 extraction without pretreatment. Native form, and microwave pretreated and untreated microalgae were observed by scanning electronic microscopy (SEM. SEM micrographs of pretreated microalgae present tearing wall agglomerates. After SCCO2, microwave pretreated microalgae presented several micro cracks; while native form microalgae wall was slightly damaged.

Microalgae as a source of liquid fuels. Final technical report. [200 references

Energy Technology Data Exchange (ETDEWEB)

Benemann, J.R.; Goebel, R.P.; Weissman, J.C.; Augenstein, D.C.

1982-05-15

The economics of liquid-fuels production from microalgae was evaluated. A detailed review of published economic analyses of microalgae biomass production revealed wide variations in the published costs, which ranged from several dollars per pound for existing commercial health-food production in the Far East, to less than .05/lb costs projected for microalgae biomass for fuel conversion. As little design information or specific cost data has been published, a credible cost estimate required the conceptual engineering design and cost estimating of microalgae to liquid-fuels processes. Two systems were analyzed, shallow (2 to 3'') covered ponds and deeper (1 ft) open ponds. Only the latter was selected for an in-depth analysis due to the many technical shortcomings of the former approach. Based on the cost analysis of a very simple and low cost process, the most optimistic costs extrapolated were about $60/barrel. These were based on many optimistic assumptions. Additional, more detailed, engieering and cost analyses would be useful. However, the major emphasis in future work in this area should be on demonstrating the basic premises on which this design was based: high productivity and oil content of microalgae strains that can dominate in open ponds and which can be harvested by a simple bioflocculation process. Several specific basic research needs were identified: (1) Fundamentals of species selection and control in open pond systems. Effects of environmental variables on species dominance is of particular interest. (2) Mechanisms of algae bioflocculation. (3) Photosynthetic pathways and efficiency under conditions of high lipid production. (4) Effects of non-steady state operating conditions, particularly pH (CO/sub 2/ availability), on productivity. 18 figures, 47 tables.

Development of a Biosensor for Environmental Monitoring Based on Microalgae Immobilized in Silica Hydrogels

Directory of Open Access Journals (Sweden)

Claude Durrieu

2012-12-01

Full Text Available A new biosensor was designed for the assessment of aquatic environment quality. Three microalgae were used as toxicity bioindicators: Chlorella vulgaris, Pseudokirchneriella subcapitata and Chlamydomonas reinhardtii. These microalgae were immobilized in alginate and silica hydrogels in a two step procedure. After studying the growth rate of entrapped cells, chlorophyll fluorescence was measured after exposure to (3-(3,4-dichlorophenyl-1,1-dimethylurea (DCMU and various concentrations of the common herbicide atrazine. Microalgae are very sensitive to herbicides and detection of fluorescence enhancement with very good efficiency was realized. The best detection limit was 0.1 µM, obtained with the strain C. reinhardtii after 40 minutes of exposure.

A three-dimensional study of the musculotendinous and neurovascular architecture of the gracilis muscle: application to functional muscle transfer.

Science.gov (United States)

Fattah, A Y; Ravichandiran, K; Zuker, R M; Agur, A M R

2013-09-01

Muscle transfer is used to restore function typically using a single vector of contraction. Although its use with two independently functional muscular units has been employed, in order to refine this concept we endeavoured to detail the intramuscular anatomy of gracilis, a muscle commonly used for transfer. A novel method to capture intramuscular fibre bundle and neurovascular arrangement was used to create a three-dimensional (3D) digital model that allowed for accurate representation of the relationships between all the intramuscular structures to facilitate flap planning. Twenty gracilis muscles were harvested from 15 cadavers. All components of the muscle were digitised using a Microscribe G2 Digitiser. The data were exported to the 3D animation software Autodesk(®) Maya(®) 2012 whereupon it was rendered into a 3D model that can be exported as static images or videos. Neurovascular anatomy and muscle architecture were analysed from these models, and fibre bundle length, pennation angle and physiological cross-sectional area were calculated from digitised data. The muscle is composed of a variable number of distinct longitudinal segments with muscle fibres spiralling onto the tendon. The main artery to the muscle has three main intramuscular patterns of distribution. The venae comitantes drain discrete zones without intramuscular macroscopic anastomoses. The minor pedicles form an anastomotic chain along the anterior border of the muscle and all vessels were biased to the deep surface. The nerve is related to the vessels in a variable manner and both run between longitudinal muscular compartments. The digitisation technique may be used to advance knowledge of intramuscular architecture and it demonstrated that the gracilis muscle is comprised of four to seven muscular compartments, each representing a functional unit that may theoretically be differentially activated and could be harnessed for more sophisticated muscle transfers. Copyright © 2013 British

TOR (target of rapamycin) is a key regulator of triacylglycerol accumulation in microalgae.

Science.gov (United States)

Imamura, Sousuke; Kawase, Yasuko; Kobayashi, Ikki; Shimojima, Mie; Ohta, Hiroyuki; Tanaka, Kan

2016-01-01

Most microalgae abundantly accumulate lipid droplets (LDs) containing triacylglycerols (TAGs) under several stress conditions, but the underlying molecular mechanism of this accumulation remains unclear. In a recent study, we found that inhibition of TOR (target of rapamycin), a highly conserved protein kinase of eukaryotes, by rapamycin resulted in TAG accumulation in microalgae, indicating that TOR negatively regulates TAG accumulation. Here, we show that formation of intracellular LDs and TAG accumulation were also induced in the unicellular green alga Chlamydomonas reinhardtii after exposure to Torin1 or AZD8055, which are novel TOR inhibitors that inhibit TOR activity in a manner different from rapamycin. These results supported quite well our previous conclusion that TOR is a central regulator of TAG accumulation in microalgae.

Direct Biodiesel Production from Wet Microalgae Biomass of Chlorella pyrenoidosa through In Situ Transesterification

Science.gov (United States)

Cao, Hechun; Zhang, Zhiling; Wu, Xuwen; Miao, Xiaoling

2013-01-01

A one-step process was applied to directly converting wet oil-bearing microalgae biomass of Chlorella pyrenoidosa containing about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production. PMID:24195081

Direct Biodiesel Production from Wet Microalgae Biomass of Chlorella pyrenoidosa through In Situ Transesterification

Directory of Open Access Journals (Sweden)

Hechun Cao

2013-01-01

Full Text Available A one-step process was applied to directly converting wet oil-bearing microalgae biomass of Chlorella pyrenoidosa containing about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production.

Direct biodiesel production from wet microalgae biomass of Chlorella pyrenoidosa through in situ transesterification.

Science.gov (United States)

Cao, Hechun; Zhang, Zhiling; Wu, Xuwen; Miao, Xiaoling

2013-01-01

A one-step process was applied to directly converting wet oil-bearing microalgae biomass of Chlorella pyrenoidosa containing about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production.

Enzymatic cell disruption of microalgae biomass in biorefinery processes.

Science.gov (United States)

Demuez, Marie; Mahdy, Ahmed; Tomás-Pejó, Elia; González-Fernández, Cristina; Ballesteros, Mercedes

2015-10-01

When employing biotechnological processes for the procurement of biofuels and bio-products from microalgae, one of the most critical steps affecting economy and yields is the "cell disruption" stage. Currently, enzymatic cell disruption has delivered effective and cost competitive results when compared to mechanical and chemical cell disruption methods. However, the introduction of enzymes implies additional associated cost within the overall process. In order to reduce this cost, autolysis of microalgae is proposed as alternative enzymatic cell disruption method. This review aims to provide the state of the art of enzymatic cell disruption treatments employed in biorefinery processes and highlights the use of endopeptidases. During the enzymatic processes of microalgae life cycle, some lytic enzymes involved in cell division and programmed cell death have been proven useful in performing cell lysis. In this context, the role of endopeptidases is emphasized. Mirroring these natural events, an alternative cell disruption approach is proposed and described with the potential to induce the autolysis process using intrinsic cell enzymes. Integrating induced autolysis within biofuel production processes offers a promising approach to reduce overall global costs and energetic input associated with those of current cell disruption methods. A number of options for further inquiry are also discussed. © 2015 Wiley Periodicals, Inc.

In vitro activity of essential oils of Lippia sidoides and Lippia gracilis and their major chemical components against Thielaviopsis paradoxa, causal agent of stem bleeding in coconut palms

Directory of Open Access Journals (Sweden)

Rejane Rodrigues da Costa e Carvalho

2013-01-01

Full Text Available Essential oils of Lippia sidoides, Lippia gracilis and their main chemical components were investigated for in vitro control of Thielaviopsis paradoxa. Mycelial growth and a number of pathogen conidia were inhibited by the essential oil of L. sidoides at all concentrations tested (0.2; 0.5; 1.0; 3.0 µL mL-1. L. sidoides oil contained 42.33% thymol and 4.56% carvacrol, while L. gracilis oil contained 10% thymol and 41.7% carvacrol. Mycelial growth and conidial production of T. paradoxa were completely inhibited by thymol at a 0.3 µL m-1 concentration. The results suggest that thymol could potentially be used for controlling coconut stem bleeding.

Outcomes of electrically stimulated gracilis neosphincter surgery.

Science.gov (United States)

Tillin, T; Chambers, M; Feldman, R

2005-07-01

To examine patient quality of life (QoL) and long-term costs of electrically stimulated gracilis neosphincter surgery (ESGNS). Independently conducted prospective case-comparison study of patients at the Royal London Hospital (RLH), plus a cross-sectional study of outcomes of ESGNS performed at three other UK centres. Cases were patients who underwent ESGNS at the participating hospitals during a 5-year period from 1977. Comparisons were made with two groups of people with similar bowel disorders who did not undergo ESGNS. ESGNS is a procedure designed to improve bowel function for people living with severe faecal incontinence or stomas. It involves transposition of the gracilis muscle to form a neo-anal sphincter. The transposed muscle is electrically stimulated via an electronic pulse generator implanted beneath the skin of the abdomen. Clinical success and symptomatic outcomes of surgery. Generic, domain and condition specific measures of QoL. Comparative costs to the NHS of ESGNS and conventional alternatives. At 3 years after surgery approximately three-quarters of patients still had functioning neosphincters. At this stage, bowel-related QoL and continence improved by more than 20% for nearly two-thirds of RLH patients. However, ongoing bowel evacuation difficulties occurred in half of those with good continence outcomes. QoL improvements were maintained in the smaller group of RLH patients who had reached 4 and 5 years of follow-up, although at this stage the proportion with failed neosphincters had increased. The RLH findings were supported by those from the three other UK centres. No significant changes in QoL were observed in the comparison groups during the follow-up period. The mean cost of patient care at RLH, was 23,253 pounds. In the other three centres, the estimated mean cost of the intervention per patient was 11,731 pounds, reflecting fewer planned operations and repeat admissions. Costs of patient care for those with stomas who did not undergo

Outdoor cultivation of microalgae for carotenoid production: current state and perspectives.

Science.gov (United States)

Del Campo, José A; García-González, Mercedes; Guerrero, Miguel G

2007-04-01

Microalgae are a major natural source for a vast array of valuable compounds, including a diversity of pigments, for which these photosynthetic microorganisms represent an almost exclusive biological resource. Yellow, orange, and red carotenoids have an industrial use in food products and cosmetics as vitamin supplements and health food products and as feed additives for poultry, livestock, fish, and crustaceans. The growing worldwide market value of carotenoids is projected to reach over US$1,000 million by the end of the decade. The nutraceutical boom has also integrated carotenoids mainly on the claim of their proven antioxidant properties. Recently established benefits in human health open new uses for some carotenoids, especially lutein, an effective agent for the prevention and treatment of a variety of degenerative diseases. Consumers' demand for natural products favors development of pigments from biological sources, thus increasing opportunities for microalgae. The biotechnology of microalgae has gained considerable progress and relevance in recent decades, with carotenoid production representing one of its most successful domains. In this paper, we review the most relevant features of microalgal biotechnology related to the production of different carotenoids outdoors, with a main focus on beta-carotene from Dunaliella, astaxanthin from Haematococcus, and lutein from chlorophycean strains. We compare the current state of the corresponding production technologies, based on either open-pond systems or closed photobioreactors. The potential of scientific and technological advances for improvements in yield and reduction in production costs for carotenoids from microalgae is also discussed.

The impact of nitrogen starvation on the dynamics of triacylglycerol accumulation in nine microalgae strains

NARCIS (Netherlands)

Breuer, G.; Lamers, P.P.; Martens, D.E.; Draaisma, R.B.; Wijffels, R.H.

2012-01-01

Microalgae-derived lipids are an alternative to vegetable and fossil oils, but lipid content and quality vary among microalgae strains. Selection of a suitable strain for lipid production is therefore of paramount importance. Based on published results for 96 species, nine strains were selected to

Antimicrobial action of the essential oil of Lippia gracilis Schauer

Directory of Open Access Journals (Sweden)

Cynthia Cavalcanti de Albuquerque

2006-07-01

Full Text Available Antimicrobial activity of the essential oil (EO of Lippia gracilis Schauer over fungi and heliconia endophytic bacteria was evaluated. For the fungi Geotrichum candidum; Trichoderma viride; Torula herbarum; Paecillomyces sp.; Fusicoccum sp.; P. aeruginens; Curvularia lunata; Aspergillus nidulans; A. flavus; and A. niger mycelial discs were inoculated in PDA medium with oil (0; 420; 440; 460; 480 e 500 µL L-1. The inhibition percentage in 420 µL L-1 was 100% for all fungi, except for C. lunata and A. niger, which was 95.58% and 89.40% , respectively. In other experiment, a suspension of the Salmonella choleraceuis-diarizonae, Enterobacter asburiae, Bacillus thuringiensis, B. pumilus, B. cereus, Klebsiella pneumoniae, and E. hormaechei was individually added to the solid NYDA medium dishes. In each dish, wells were drilled in medium and filled with water or EO (420 µL L-1. The diameter of the inhibition halo was assessed. K. pneumoniae was the bacterial species less sensitive and E. hormaechei was the most sensitive.Avaliou-se a atividade antimicrobiana do óleo essencial (OE de Lippia gracilis Schauer sobre fungos contaminantes de laboratórios de cultura de tecidos vegetais e bactérias endofíticas de helicônias. Discos de micélio dos fungos Geotrichum candidum; Trichoderma viride; Torula herbarum; Paecillomyces sp.; Aspergillus nidulans; Fusicoccum sp.; A. flavus; P. aeruginens; Curvularia lunata e A. niger, foram inoculados em meio BDA com óleo (0; 420; 440; 460; 480 e 500 µL L-1. O percentual de inibição em 420 µL L-1 foi de 100% para todos os fungos exceto paraC. lunata and A. niger, o qual foi de 95.58% and 89.40% respectivamente. Em outro experimento, suspensão das espécies Salmonela choleraceuis-diarizonae, Enterobacter asburiae, Bacillus thuringiensis, B. pumilus, Klebsiella pneumoniae, E. hormaechei, Bacillus pumilus, B. cereus, B. pumilus foi individualmente adicionada ao meio NYDA, que foi vertido em placas de Petri e, ap

Membrane Proteomic Insights into the Physiology and Taxonomy of an Oleaginous Green Microalga.

Science.gov (United States)

Garibay-Hernández, Adriana; Barkla, Bronwyn J; Vera-Estrella, Rosario; Martinez, Alfredo; Pantoja, Omar

2017-01-01

Ettlia oleoabundans is a nonsequenced oleaginous green microalga. Despite the significant biotechnological interest in producing value-added compounds from the acyl lipids of this microalga, a basic understanding of the physiology and biochemistry of oleaginous microalgae is lacking, especially under nitrogen deprivation conditions known to trigger lipid accumulation. Using an RNA sequencing-based proteomics approach together with manual annotation, we are able to provide, to our knowledge, the first membrane proteome of an oleaginous microalga. This approach allowed the identification of novel proteins in E. oleoabundans, including two photoprotection-related proteins, Photosystem II Subunit S and Maintenance of Photosystem II under High Light1, which were considered exclusive to higher photosynthetic organisms, as well as Retinitis Pigmentosa Type 2-Clathrin Light Chain, a membrane protein with a novel domain architecture. Free-flow zonal electrophoresis of microalgal membranes coupled to liquid chromatography-tandem mass spectrometry proved to be a useful technique for determining the intracellular location of proteins of interest. Carbon-flow compartmentalization in E. oleoabundans was modeled using this information. Molecular phylogenetic analyses of protein markers and 18S ribosomal DNA support the reclassification of E. oleoabundans within the trebouxiophycean microalgae, rather than with the Chlorophyceae class, in which it is currently classified, indicating that it may not be closely related to the model green alga Chlamydomonas reinhardtii A detailed survey of biological processes taking place in the membranes of nitrogen-deprived E. oleoabundans, including lipid metabolism, provides insights into the basic biology of this nonmodel organism. © 2017 American Society of Plant Biologists. All Rights Reserved.

Culture of microalgae biomass for valorization of table olive processing water; Cultivo de biomasa de microalgas para la valorización del agua de elaboración de las aceitunas de mesa

Energy Technology Data Exchange (ETDEWEB)

Contreras, C.G.; Serrano, A.; Ruiz-Filippi, G.; Borja, R.; Fermoso, F.G.

2016-07-01

Table olive processing water (TOPW) contains many complex substances, such as phenols, which could be valorized as a substrate for microalgae biomass culture. The aim of this study was to assess the capability of Nannochloropsis gaditana to grow in TOPW at different concentrations (10- 80%) in order to valorize this processing water. Within this range, the highest increment of biomass was determined at percentage of 40% of TOPW, reaching an increment of 0.36 ± 0.05 mg volatile suspended solids (VSS)/L. Components of algal biomass were similar for the experiments at 10-40% of TOPW, where proteins were the major compounds (56-74%). Total phenols were retained in the microalgae biomass (0.020 ± 0.002 g of total phenols/g VSS). Experiments for 80% of TOPW resulted in a low production of microalgae biomass. High organic matter, nitrogen, phosphorus and phenol removal were achieved in all TOPW concentrations. Although high-value products, such as proteins, were obtained and high removal efficiencies of nutrients were determined, microalgae biomass culture should be enhanced to become a suitable integral processing water treatment. [Spanish] El agua resultante del proceso de elaboración de la aceituna de mesa (TOPW) presenta un elevado contenido en sustancias complejas, como fenoles, que podría permitir su uso como sustrato para el cultivo de microalgas. El objetivo de este estudio se centra en evaluar la capacidad de crecimiento de annochloropsis gaditana en TOPW a distintas concentraciones (10-80%) con vistas a la valorización de estas aguas. El mayor incremento de biomasa se obtuvo para un porcentaje del 40% de TOPW, alcanzando un aumento de 0.36 ± 0.50 mg sólidos en suspensión volátiles (SSV)/L. Los componentes presentes en la biomasa han sido similares para los experimentos con 10-40% de TOPW, siendo las proteínas los compuestos mayoritarios en todos los casos (56-74%). Los fenoles totales quedaron retenidos en las microalgas, alcanzando una concentraci

Harvesting microalgae with microwave synthesized magnetic microparticles

Czech Academy of Sciences Publication Activity Database

Procházková, G.; Šafařík, Ivo; Brányik, T.

2013-01-01

Roč. 130, FEB (2013), s. 472-477 ISSN 0960-8524 R&D Projects: GA MŠk LH12190 Institutional support: RVO:67179843 Keywords : harvesting microalgae * iron oxide magnetic microparticles * non-covalent interactions * microwave treatment * cell demagnetization Subject RIV: EI - Biotechnology ; Bionics Impact factor: 5.039, year: 2013

Enhancement of Biomass and Lipid Productivities of Water Surface-Floating Microalgae by Chemical Mutagenesis.

Science.gov (United States)

Nojima, Daisuke; Ishizuka, Yuki; Muto, Masaki; Ujiro, Asuka; Kodama, Fumito; Yoshino, Tomoko; Maeda, Yoshiaki; Matsunaga, Tadashi; Tanaka, Tsuyoshi

2017-05-27

Water surface-floating microalgae have great potential for biofuel applications due to the ease of the harvesting process, which is one of the most problematic steps in conventional microalgal biofuel production. We have collected promising water surface-floating microalgae and characterized their capacity for biomass and lipid production. In this study, we performed chemical mutagenesis of two water surface-floating microalgae to elevate productivity. Floating microalgal strains AVFF007 and FFG039 (tentatively identified as Botryosphaerella sp. and Chlorococcum sp., respectively) were exposed to ethyl methane sulfonate (EMS) or 1-methyl-3-nitro-1-nitrosoguanidine (MNNG), and pale green mutants (PMs) were obtained. The most promising FFG039 PM formed robust biofilms on the surface of the culture medium, similar to those formed by wild type strains, and it exhibited 1.7-fold and 1.9-fold higher biomass and lipid productivities than those of the wild type. This study indicates that the chemical mutation strategy improves the lipid productivity of water surface-floating microalgae without inhibiting biofilm formation and floating ability.

Numerical investigation of a bubble-column photo-bioreactor design for biodiesel production from microalgae

Energy Technology Data Exchange (ETDEWEB)

Seo, I.H.; Lee, I.B.; Hwang, H.S.; Hong, S.W.; Bitog, J.P.; Kwon, K.S.; Choi, J.S.; Song, S.H. [Seoul National Univ., Seoul (Korea, Democratic People' s Republic of). Dept. of Rural Systems Engineering and Research Inst. for Agriculture and Life Sciences

2010-07-01

Biodiesel made from vegetable oil is among the most desirable of renewable energy sources because it can be a substitute for diesel oil. However, biodiesel from soybean or corn can be confronted with a food crisis. Microalgae is a new biodiesel source which contains high oil lipids with a high growth rate, and which also offers value-added products from the residue, such as cosmetics, health functional food or pharmaceuticals. Microalgae are best cultivated in photo-bioreactors (PBRs) where light, nutrients, carbon dioxide and temperature can be controlled. Despite the current availability of PBRs, only a few can be practically used for mass production. Computational fluid dynamics (CFD) was used in this study to design an optimum bubble-column PBR for mass production of microalgae. Multi-phase models including bubble movement, meshes and time step independent tests were considered to develop the 3-dimensional CFD model. Particle Image Velocimetry (PIV) tests were used to enhance and validate the model. Different types of PBRs were simulated and compared quantitatively with the microalgae's growth model.

The analysis on energy and environmental impacts of microalgae-based fuel methanol in China

International Nuclear Information System (INIS)

Liu Jing; Ma Xiaoqian

2009-01-01

The whole life of methanol fuel, produced by microalgae biomass which is a kind of renewable energy, is evaluated by using a method of life cycle assessment (LCA). LCA has been used to identify and quantify the environment emissions and energy efficiency of the system throughout the whole life cycle, including microalgae cultivation, methanol conversion, transport, and end-use. Energy efficiency, defined as the ratio of the energy of methanol produced to the total required energy, is 1.24, the results indicate that it is plausible as an energy producing process. The environmental impact loading of microalgae-based fuel methanol is 0.187mPET 2000 in contrast to 0.828mPET 2000 for gasoline. The effect of photochemical ozone formation is the highest of all the calculated categorization impacts of the two fuels. Utilization of microalgae an raw material of producing methanol fuel is beneficial to both production of renewable fuels and improvement of the ecological environment. This Fuel methanol is friendly to the environment, which should take an important role in automobile industry development and gasoline fuel substitute

Isolation and Characterization of Native Microalgae from the Peruvian Amazon with Potential for Biodiesel Production

Directory of Open Access Journals (Sweden)

Marianela Cobos

2017-02-01

Full Text Available Biodiesel production from microalgae triacylglycerols is growing, because this feedstock is a more sustainable and advantageous alternative. In this study, we isolated and identified fourteen strains of native microalgae from the Peruvian Amazon. These strains showed great heterogeneity in biomass productivity, lipid productivity and lipid content, and thus, three of them (Acutodesmus obliquus, Ankistrodesmus sp. and Chlorella lewinii were selected for further evaluation under culture of nitrogen-sufficient (+N and nitrogen-deficient (−N Chu medium No. 10. These microalgae species showed modifications in biomolecule content (protein, lipid and carbohydrate with a pronounced increase of lipids and carbohydrate and a decrease of protein content under stress culture. Furthermore, the fatty acid profile was peculiar for each species, and these patterns showed evident changes, particularly in the proportion of saturated and monounsaturated fatty acids. The results of this research suggest that the isolated native microalgae, from the Peruvian Amazon, could be suitable candidates for biodiesel production

Biological Carbon Dioxide Assimilation Process Using Marine Phytoplankton Tetraselmis suecica and Bivalve Perna viridis

Directory of Open Access Journals (Sweden)

Sirichai Dharmvanij

2012-01-01

Full Text Available The Biological CO2 assimilation process using marine phytoplankton and marine bivalve was evaluated by carbon assimilation of the green mussel Perna viridis fed with Tetraselmis suecica under laboratory condition. Incorporation of carbon dioxide into phytoplankton biomass was performed through aeration. The experiment consisted of three treatments i.e. mussels without feeding (Control, mussels fed with T. suecica cultured with air (Treatment 1: T-Air, and mussels fed with T. suecica cultured with 1.5% CO2 in air (Treatment 2: T-CO2. The results showed that growth of mussels in T-Air and T-CO2 was 22.4 ± 4.0 mg/individual/day and 28.9 ± 12.3 mg/individual/day, respectively, which was significantly higher than control (mussels without feeding. Growth of mussels in T-Air was significantly lower than in T-CO2. Carbon content in shell (15.59 ± 0.57 % D.W. and meat (38.28 ± 1.72 % D.W. of mussels fed with aerated T. suecica (T-Air was significantly higher than that found in mussels fed with 1.5% CO2 T. suecica (14.2 ± 0.47 and 36.61± 0.43 % D.W. in shell and in meat, respectively (p≤0.05. With T-Air, 1.95±0.27 and 9.36±1.24% of carbon from T. suecica cells was assimilated into shell and meat of the mussel, respectively, while in T-CO2 , carbon assimilation from T. suecica cells in shell and meat was 2.19±0.55 and 11.22±2.76% respectively.

Terpenes as Green Solvents for Extraction of Oil from Microalgae

Directory of Open Access Journals (Sweden)

Celine Dejoye Tanzi

2012-07-01

Full Text Available Herein is described a green and original alternative procedure for the extraction of oil from microalgae. Extractions were carried out using terpenes obtained from renewable feedstocks as alternative solvents instead of hazardous petroleum solvents such as n-hexane. The described method is achieved in two steps using Soxhlet extraction followed by the elimination of the solvent from the medium using Clevenger distillation in the second step. Oils extracted from microalgae were compared in terms of qualitative and quantitative determination. No significant difference was obtained between each extract, allowing us to conclude that the proposed method is green, clean and efficient.

A new homolog of FocA transporters identified in cadmium-resistant Euglena gracilis

International Nuclear Information System (INIS)

Delomenie, Claudine; Foti, Emilie; Floch, Enora; Diderot, Vimala; Porquet, Dominique; Dupuy, Corinne; Bonaly, Jacqueline

2007-01-01

To better understand the cellular mechanism of stress resistance to various pollutants (cadmium, pentachlorophenol), we undertook a survey of the Euglena gracilis transcriptome by mRNA differential display and cDNA cloning. We performed a real-time RT-PCR analysis upon four selected genes. One of them significantly changed its expression level in response to stress treatments: B25 gene was overexpressed in Cd-resistant cells whereas it was down-regulated in PCP-adapted cells. By Race assays we obtained for B25 a 1093 bp cDNA. The deduced protein was identified as a bacterial formate/nitrite transporter (FocA) homolog and the gene was named EgFth. From all the data, we concluded that EgFth overexpression was related to chronic exposure to cadmium

Antibacterial and antifungal activities of selected microalgae and cyanobacteria

Czech Academy of Sciences Publication Activity Database

Najdenski, H. M.; Gigova, L. G.; Iliev, I. I.; Pilarski, P. S.; Lukavský, Jaromír; Tsvetkova, I. V.; Ninova, M. S.; Kussovski, V. K.

2013-01-01

Roč. 48, č. 7 (2013), s. 1533-1540 ISSN 0950-5423 Institutional support: RVO:67985939 Keywords : antimicrobial activity * cyanobacteria * microalgae Subject RIV: EF - Botanics Impact factor: 1.354, year: 2013

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...

Photoacclimation state determines the photobehaviour of motile microalgae

DEFF Research Database (Denmark)

Ezequiel, João; Laviale, Martin; Frankenbach, Silja

2015-01-01

High productivity in intertidal microphytobenthic communities is achieved despite exposure to extreme and dynamic conditions (e.g. light, salinity, temperature). As an adaptation to this hostile environment, most of the microalgae species inhabiting fine-sediment habitats are motile, being able...

Review and experimental study on pyrolysis and hydrothermal liquefaction of microalgae for biofuel production

International Nuclear Information System (INIS)

Chiaramonti, David; Prussi, Matteo; Buffi, Marco; Rizzo, Andrea Maria; Pari, Luigi

2017-01-01

Highlights: • A review of microalgae thermochemical conversion to bioliquids was carried out. • We focused on pyrolysis and hydrothermal liquefaction for biocrude/biofuels. • Original experimental research on microalgae pyrolysis was also carried out. • Starvation does not impact significant on the energy content of the biocrude. • This result is relevant for designing full scale microalgae production plants. - Abstract: Advanced Biofuels steadily developed during recent year, with several highly innovative processes and technologies explored at various scales: among these, lignocellulosic ethanol and CTO (Crude Tall Oil)-biofuel technologies already achieved early-commercial status, while hydrotreating of vegetable oils is today fully commercial, with almost 3.5 Mt/y installed capacity worldwide. In this context, microalgae grown in salt-water and arid areas represent a promising sustainable chain for advanced biofuel production but, at the same time, they also represent a considerable challenge. Processing microalgae in an economic way into a viable and sustainable liquid biofuel (a low-cost mass-product) is not trivial. So far, the most studied microalgae-based biofuel chain is composed by microorganism cultivation, lipid accumulation, oil extraction, co-product valorization, and algae oil conversion through conventional esterification into Fatty Acids Methyl Esters (FAME), i.e. Biodiesel, or Hydrotreated Esters and Fatty Acids (HEFA), the latter representing a very high quality drop-in biofuel (suitable either for road transport or for aviation). However, extracting the algae oil at low cost and industrial scale is not yet a mature process, and there is not yet industrial production of algae-biofuel from these two lipid-based chains. Another option can however be considered: processing the algae through dedicated thermochemical reactors into advanced biofuels, thus approaching the downstream processing of algae in a completely different way than

Quantification of Heavy Metals and Other Inorganic Contaminants on the Productivity of Microalgae

OpenAIRE

Napan, Katerine; Hess, Derek; McNeil, Brian; Quinn, Jason C.

2015-01-01

Increasing demand for renewable fuels has researchers investigating the feasibility of alternative feedstocks, such as microalgae. Inherent advantages include high potential yield, use of non-arable land and integration with waste streams. The nutrient requirements of a large-scale microalgae production system will require the coupling of cultivation systems with industrial waste resources, such as carbon dioxide from flue gas and nutrients from wastewater. Inorganic contaminants present in t...

Coagulant effect of ferric chloride for separation of biomass from the microalgae Chlorella sp. of the water; Efeito coagulante do cloreto ferrico para separacao da biomassa da microalga Chlorella sp. da agua

Energy Technology Data Exchange (ETDEWEB)

Souza, Tamara Daiane de; Mendes, Mucio Andre dos Santos Alves [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola e Ambiental], E-mail: tamara_daiane@yahoo.com.br; Matos, Antonio Teixeira de [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola; Lo Monaco, Paola Alfonsa Vieira [Instituto Federal do Espirito Santo (IFES), Santa Teresa, ES (Brazil); Universidade Federal de Vicosa (DEA/UFV), MG (Brazil). Dept. de Engenharia Agricola

2010-07-01

Currently, much interest has been focused on the biotechnological potential of microalgae, mainly in the production of biofuels. For this to become viable the biomass of algae should be separated from the water and the process of coagulation/flocculation/sedimentation may be an alternative. This study aimed to evaluate the effect of ferric chloride as coagulant agent of the microalgae Chlorella vulgaris. Were tested five concentrations of ferric chloride in the suspension containing the microalgae: 20,0; 30,0; 40,0; 50,0 e 100,0 g L{sup -1}. The tests were performed using the Jar-test apparatus and the turbidity was measured in suspensions after 2 hours of sedimentation. Mathematical equations were adjusted by regression, relating the concentration used in the tests according to the turbidity of the suspension. There was a linear decrease in turbidity with the addition of ferric chloride, and for concentration of 100.0 g L{sup -1} was achieved a removal efficiency of turbidity of 58%. However, it is necessary to conduct further research, evaluating the economic feasibility of the technique in the separation of microalgae from the water. (author)

[Genital elephantiasis: reconstructive treatment of penoscrotal lymphoedema with a myocutaneous M. gracilis flap. Experiences from a District Hospital in Ethiopia].

Science.gov (United States)

Prica, S; Donati, O F; Schaefer, D J; Peltzer, J

2008-08-01

Genital elephantiasis is an illness leading to serious functional and aesthetic as well as psychosocial impairment. Since the 19th century there have been articles describing methods for surgical ablative treatment of penoscrotal lymphoedema. However, most of these methods ignore the creation a new drainage for the lymph. We now describe a new technique using a myocutaneous M. gracilis muscle flap for the reconstruction of the soft tissue damage resulting from radical excision, thus ensuring drainage of the lymph into the deep muscle compartment of the thigh. In the District Hospital "Mettu-Karl Hospital" in the Ethiopian rain forest region of Illubabor, during a period of 6 months the described surgical procedure was applied to 9 patients suffering from severe forms of this grotesquely disfiguring disease. Two patients presented with combined penoscrotal oedema, while the other 7 patients were suffering from isolated scrotal lymphoedema alone. All patients benefited from reconstruction with a myocutaneous M. gracilis muscle flap after radical excision of the affected tissue. All patients were evaluated after 3 and 12 months postoperatively in the presence of a translator. All nine patients showed a functionally and aesthetically satisfying result after 3 months without postoperative occurrence of infection. The evaluation 12 months postoperatively showed no recurrence of genitoscrotal lymphoedema. All patients reported on having regained normal ability for sexual intercourse and no occurrence of urinary tract infections since the operation. Concerning fertility, no statements could be made. A significant improvement in the quality of life was observed by the regained ability to walk and work and consequently the reintegration of the patients into their socio-economic environment. Radical excision of the affected tissue followed by transferring a functioning lymphatic drainage into the deep muscle compartment of the ipsilateral thigh using a proximally based

Isolation and application of SO{sub X} and NO{sub X} resistant microalgae in biofixation of CO{sub 2} from thermoelectricity plants

Energy Technology Data Exchange (ETDEWEB)

Radmann, Elisangela Martha; Vieira Camerini, Felipe; Duarte Santos, Thaisa [Laboratory of Biochemical Engineering, College of Chemistry and Food Engineering, Federal University of Rio Grande (FURG), P.O. Box 474, Rio Grande-RS 96201-900 (Brazil); Vieira Costa, Jorge Alberto, E-mail: dqmjorge@furg.br [Laboratory of Biochemical Engineering, College of Chemistry and Food Engineering, Federal University of Rio Grande (FURG), P.O. Box 474, Rio Grande-RS 96201-900 (Brazil)

2011-09-15

Highlights: {yields} Microalgae can help reduce global warming. {yields} Synechococcus nidulans and Chlorella vulgaris were isolated in a thermoelectric plant. {yields} Microalgae were compared with Spirulina and Scenedesmus obliquus for CO{sub 2} fixation. {yields} Microalgae were exposed to CO{sub 2}, SO{sub 2} and NO, simulating a gas from coal combustion. {yields} C. vulgaris and Spirulina sp. showed 13.43% of maximum daily fixation. - Abstract: Microalgae have been studied for their potential use in foodstuffs, agriculture, in the treatment of wastewater and, in particular, in the reduction of atmospheric carbon dioxide, the main cause of global warming. Thermoelectricity plants account for 22% of CO{sub 2} emitted into the atmosphere and native microalgae may be more tolerant to the gases emitted from burning fossil fuels. In the study presented here, microalgae were isolated from ponds next to a Thermoelectricity Plant, located in southern Brazil, and identified as Synechococcus nidulans and Chlorella vulgaris. The isolated microalgae were grown and compared with two different strains of microalgae, Spirulina sp. and Scenedesmus obliquus, for CO{sub 2} biofixation. The microalgae were exposed to 12% CO{sub 2}, 60 ppm of SO{sub 2} and 100 ppm of NO, simulating a gas from coal combustion. The C. vulgaris had similar behavior to Spirulina sp., with 13.43% of maximum daily fixation. The microalgae with the greater fixing capacity were C. vulgaris and Spirulina sp. and these can be grown in electric power plants for CO{sub 2} biofixation of the coal combustion gas, which would help reduce global warming.

Use of gastrointestinal anastomosis stapler for harvest of gracilis muscle and securing it in the face for facial reanimation: a novel technique.

Science.gov (United States)

Shridharani, Sachin M; Stapleton, Sahael M; Redett, Richard J; Magarakis, Michael; Rosson, Gedge D

2010-04-08

The primary objective of this study is to report a novel technique that uses the gastrointestinal anastomosis (GIA) stapler for harvesting and securing the gracilis muscle in facial reanimation surgery. We conducted a retrospective chart review with 18 consecutive patients who underwent gracilis muscle flap transfer with or without the use of a GIA stapler. Of 11 operations with the GIA stapler, one patient developed a hematoma (donor site) and another required drainage of an abscess (recipient site). Of 8 operations without the use of the stapler, one patient had total flap failure and three required drainage of an abscess (2 recipient sites and 1 donor site). These differences trended toward improvement but were not statistically different. The use of the GIA stapler is a fast, safe technique. Larger studies are, however, warranted to further examine this novel approach in order to test precisely what factors of increased efficiency occur, the amount of suture pull-through, and overall tension capable of being applied to the secured staple line.

Polishing of municipal secondary effluent using native microalgae consortia.

Science.gov (United States)

Beltrán-Rocha, Julio César; Barceló-Quintal, Icela Dagmar; García-Martínez, Magdalena; Osornio-Berthet, Luis; Saavedra-Villarreal, Nidia; Villarreal-Chiu, Juan; López-Chuken, Ulrico Javier

2017-04-01

This work evaluates the use of native microalgae consortia for a dual role: polishing treatment of municipal wastewater effluents and microalgae biomass feedstock potential for biodiesel or biofertilizer production. An initial screening was undertaken to test N and P removal from secondary effluents and biomass production by 12 consortia. A subsequent treatment was performed by selected consortia (01 and 12) under three operational conditions: stirring (S), S + 12 h of daily aeration (S + A) and S + A enriched with CO 2 (S + AC). All treatments resulted in compliance with environmental regulations (e.g. Directive 91/271/EEC) and high removal efficiency of nutrients: 64-79% and 80-94% of total N and PO 4 3- -P respectively. During the experiments it was shown that pH alkalinization due to microalgae growth benefits the chemical removal of ammonia and phosphorus. Moreover, advantages of pH increase could be accomplished by intermittent CO 2 addition which in this research (treatment S + AC) promoted higher yield and lipid concentration. The resulting dry biomass analysis showed a low lipid content (0.5-4.3%) not ideal for biodiesel production. Moreover, the high rate of ash (29.3-53.0%) suggests that biomass could be readily recycled as a biofertilizer due to mineral supply and organic constituents formed by C, N and P (e.g. carbohydrate, protein, and lipids).

Utilization of organic residues using heterotrophic microalgae and insects.

Science.gov (United States)

Pleissner, Daniel; Rumpold, Birgit A

2018-02-01

Various organic residues occur globally in the form of straw, wood, green biomass, food waste, feces, manure etc. Other utilization strategies apart from anaerobic digestion, composting and incineration are needed to make use of the whole potential of organic residues as sources of various value added compounds. This review compares the cultivation of heterotrophic microalgae and insects using organic residues as nutrient sources and illuminates their potential with regard to biomass production, productivity and yield, and utilization strategies of produced biomasses. Furthermore, cultivation processes as well as advantages and disadvantages of utilization processes are identified and discussed. It was shown that both heterotrophic algae and insects are able to reduce a sufficient amount of organic residues by converting it into biomass. The biomass composition of both organisms is similar which allows similar utilization strategies in food and feed, chemicals and materials productions. Even though insect is the more complex organism, biomass production can be carried out using simple equipment without sterilization and hydrolysis of organic residues. Contrarily, heterotrophic microalgae require a pretreatment of organic residues in form of sterilization and in most cases hydrolysis. Interestingly, the volumetric productivity of insect biomass exceeds the productivity of algal biomass. Despite legal restrictions, it is expected that microalgae and insects will find application as alternative food and feed sources in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mixed Wastewater Coupled with CO2 for Microalgae Culturing and Nutrient Removal.

Directory of Open Access Journals (Sweden)

Lili Yao

Full Text Available Biomass, nutrient removal capacity, lipid productivity and morphological changes of Chlorella sorokiniana and Desmodesmus communis were investigated in mixed wastewaters with different CO2 concentrations. Under optimal condition, which was 1:3 ratio of swine wastewater to second treated municipal wastewater with 5% CO2, the maximum biomass concentrations were 1.22 g L-1 and 0.84 g L-1 for C. sorokiniana and D. communis, respectively. Almost all of the ammonia and phosphorus were removed, the removal rates of total nitrogen were 88.05% for C. sorokiniana and 83.18% for D. communis. Lipid content reached 17.04% for C. sorokiniana and 20.37% for D. communis after 10 days culture. CO2 aeration increased intracellular particle numbers of both microalgae and made D. communis tend to be solitary. The research suggested the aeration of CO2 improve the tolerance of microalgae to high concentration of NH4-N, and nutrient excess stress could induce lipid accumulation of microalgae.

Assessing microalgae biorefinery routes for the production of biofuels via hydrothermal liquefaction.

Science.gov (United States)

López Barreiro, Diego; Samorì, Chiara; Terranella, Giuseppe; Hornung, Ursel; Kruse, Andrea; Prins, Wolter

2014-12-01

The interest in third generation biofuels from microalgae has been rising during the past years. Meanwhile, it seems not economically feasible to grow algae just for biofuels. Co-products with a higher value should be produced by extracting a particular algae fraction to improve the economics of an algae biorefinery. The present study aims at analyzing the influence of two main microalgae components (lipids and proteins) on the composition and quantity of biocrude oil obtained via hydrothermal liquefaction of two strains (Nannochloropsis gaditana and Scenedesmus almeriensis). The algae were liquefied as raw biomass, after extracting lipids and after extracting proteins in microautoclave experiments at different temperatures (300-375°C) for 5 and 15min. The results indicate that extracting the proteins from the microalgae prior to HTL may be interesting to improve the economics of the process while at the same time reducing the nitrogen content of the biocrude oil. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparative effects of herbicides on photosynthesis and growth of tropical estuarine microalgae

Energy Technology Data Exchange (ETDEWEB)

Magnusson, Marie [AIMS at JCU, Australian Institute of Marine Science, School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811 (Australia); School of Marine and Tropical Biology, James Cook University, Douglas Campus, Townsville 4811 (Australia); Heimann, Kirsten [School of Marine and Tropical Biology, James Cook University, Douglas Campus, Townsville 4811 (Australia)], E-mail: Kirsten.Heimann@jcu.edu.au; Negri, Andrew P. [Australian Institute of Marine Science, PMB 3 Townsville MC, QLD 4810 (Australia)

2008-09-15

Pulse amplitude modulation (PAM) fluorometry is ideally suited to measure the sub-lethal impacts of photosystem II (PSII)-inhibiting herbicides on microalgae, but key relationships between effective quantum yield [Y(II)] and the traditional endpoints growth rate ({mu}) and biomass increase are unknown. The effects of three PSII-inhibiting herbicides; diuron, hexazinone and atrazine, were examined on two tropical benthic microalgae; Navicula sp. (Heterokontophyta) and Nephroselmis pyriformis (Chlorophyta). The relationships between Y(II), {mu} and biomass increase were consistent (r{sup 2} {>=} 0.90) and linear (1:1), validating the utility of PAM fluorometry as a rapid and reliable technique to measure sub-lethal toxicity thresholds of PSII-inhibiting herbicides in these microalgae. The order of toxicity (EC{sub 50} range) was: diuron (16-33 nM) > hexazinone (25-110 nM) > atrazine (130-620 nm) for both algal species. Growth rate and photosynthesis were affected at diuron concentrations that have been detected in coastal areas of the Great Barrier Reef.

Comparative effects of herbicides on photosynthesis and growth of tropical estuarine microalgae

International Nuclear Information System (INIS)

Magnusson, Marie; Heimann, Kirsten; Negri, Andrew P.

2008-01-01

Pulse amplitude modulation (PAM) fluorometry is ideally suited to measure the sub-lethal impacts of photosystem II (PSII)-inhibiting herbicides on microalgae, but key relationships between effective quantum yield [Y(II)] and the traditional endpoints growth rate (μ) and biomass increase are unknown. The effects of three PSII-inhibiting herbicides; diuron, hexazinone and atrazine, were examined on two tropical benthic microalgae; Navicula sp. (Heterokontophyta) and Nephroselmis pyriformis (Chlorophyta). The relationships between Y(II), μ and biomass increase were consistent (r 2 ≥ 0.90) and linear (1:1), validating the utility of PAM fluorometry as a rapid and reliable technique to measure sub-lethal toxicity thresholds of PSII-inhibiting herbicides in these microalgae. The order of toxicity (EC 50 range) was: diuron (16-33 nM) > hexazinone (25-110 nM) > atrazine (130-620 nm) for both algal species. Growth rate and photosynthesis were affected at diuron concentrations that have been detected in coastal areas of the Great Barrier Reef

Inventory of Sources of Available Saline Waters for Microalgae Mass Culture in the State of Arizona

Energy Technology Data Exchange (ETDEWEB)

Wilson, L. G.; Olson, K. L.; Wallace, M. G.; Osborn, M. D.

1986-06-25

The Solar Energy Research Institute (SERI) is conducting research on the development of microalgae biomass systems for the production of liquid fuels. Particularly appealing at this time, is the idea of using indigenous resources of the Southwest for large-scale production of microalgae.

Microalgae respond differently to nitrogen availability during culturing

Indian Academy of Sciences (India)

Variations in the exogenous nitrogen level are known to significantly affect the physiological status and metabolism of microalgae. However, responses of red, green and yellow-green algae to nitrogen (N) availability have not been compared yet. Porphyridium cruentum, Scenedesmus incrassatulus and Trachydiscus ...

Edible oils from microalgae: insights in TAG accumulation

NARCIS (Netherlands)

Klok, A.J.; Lamers, P.P.; Martens, D.E.; Draaisma, R.B.; Wijffels, R.H.

2014-01-01

Microalgae are a promising future source for sustainable edible oils. To make microalgal oil a cost-effective alternative for common vegetable oils, increasing TAG productivity and TAG content are of high importance. Fulfilling these targets requires proper understanding of lipid metabolism in

NÚMERO CROMOSSÔMICO DE Lippia gracilis Schauer (VERBENACEAE OCORRENTES NO ESTADO DO RIO GRANDE DO NORTE, BRASIL

Directory of Open Access Journals (Sweden)

LUIS EDUARDO DE SOUSA SOARES

2011-01-01

Full Text Available The genus Lippia (Verbenaceae comprises about 200 species of pantropical distribution. Lippia gracilis Schauer, popularly known as the mountain balm, is an aromatic plant, native of northeastern Brazil, used in folk medicine as an antiseptic and to treat dermatitis. Although cytogenetic serve as a tool in taxonomy rate, cytogenetical studies of genus Lippia are restricted. Given the above, the present study aimed to determine, at the first time, the chromosome number of copies of L. gracilis, and thereby contribute to a better taxonomic understanding of this genus. In this sense root tips collected from newly planted specimens were pretreated with a solution of 2mM 8-hydroxyquinoline for 4 hours, fixed in Carnoy 3:1 (ethanol: acetic acid for 24 hours and stored in the same fixative for later analysis. The roots were hydrolyzed in 5N HCl for 20 minutes and the slides, prepared by squashing in acetic acid (45% and stained with 2% Giemsa. The best metaphases were photographed and pointed to the chromosome number 2n = 24. Moreover, were observed metacentric and submetacentric chromosomes. Because there are several chromosome numbers in the genus, from n=10 to n=30, and as the same is little known cytogenetically, f more comprehensive cytogenetic studies are necessary, involving a larger number of species, so these data may help to clarify taxonomic inconsistencies in the family Verbenaceae.

Hazard and risk of herbicides for marine microalgae.

Science.gov (United States)

Sjollema, Sascha B; Martínezgarcía, Gema; van der Geest, Harm G; Kraak, Michiel H S; Booij, Petra; Vethaak, A Dick; Admiraal, Wim

2014-04-01

Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol(®)1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally. Copyright © 2013 Elsevier Ltd. All rights reserved.

Physiological-phased kinetic characteristics of microalgae Chlorella vulgaris growth and lipid synthesis considering synergistic effects of light, carbon and nutrients.

Science.gov (United States)

Liao, Qiang; Chang, Hai-Xing; Fu, Qian; Huang, Yun; Xia, Ao; Zhu, Xun; Zhong, Nianbing

2018-02-01

To comprehensively understand kinetic characteristics of microalgae growth and lipid synthesis in different phases, a phase-feeding strategy was proposed to simultaneously regulate light, carbon and nutrients in adaption, growth and stationary phases of microalgae cultivation. Physiological-phased kinetic characteristics of microalgae Chlorella vulgaris growth and lipid synthesis under synergistic effects of light, carbon and nutrients were investigated, and supply-demand relationships of electrons and energy between light and dark reactions of photosynthesis process were discussed. Finally, the optimized cultivation strategy for microalgae in various phases were obtained, under which the lipid productivity was significantly improved from 130.11 mg/L/d to 163.42 mg/L/d. The study provided some important guidance for the large-scale production of biofuels from microalgae. Copyright © 2017 Elsevier Ltd. All rights reserved.

Renewable energy technologies: enlargement of biofuels list and co-products from microalgae

Directory of Open Access Journals (Sweden)

Chernova Nadezhda I.

2017-01-01

Full Text Available Microalgae is a perspective feedstock for producing a wide variety of biofuels and co-products with high added value. An alternative to the traditional technology of biodiesel from algae by the transesterification is the technology of hydrothermal liquefaction (HTL. The article presents the results of promising strains screening and directed cultivation of microalgae for the processing by means of variety of technologies and production of valuable co-products. An algorithm for selecting suitable areas for industrial plantations of algae is presented.

RECOVERY AND SEQUESTRATION OF CO2 FROM STATIONARY COMBUSTION SYSTEMS BY PHOTOSYNTHESIS OF MICROALGAE

Energy Technology Data Exchange (ETDEWEB)

Dr. T. Nakamura; Dr. Miguel Olaizola; Dr. Steven M. Masutani

2001-08-01

Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 April to 30 June 2001 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work conducted during the previous reporting period, PSI initiated work on the component optimization work. Aquasearch continued their effort on selection of microalgae suitable for CO{sub 2} sequestration. University of Hawaii initiated effort on system optimization of the CO{sub 2} sequestration system.

RECOVERY AND SEQUESTRATION OF CO2 FROM STATIONARY COMBUSTION SYSTEMS BY PHOTOSYNTHESIS OF MICROALGAE

Energy Technology Data Exchange (ETDEWEB)

Dr. T. Nakamura; Dr. Miguel Olaizola; Dr. Stephen M. Masutani

2002-03-01

Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 October to 31 December 2001 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work conducted during the previous reporting period, PSI initiated work on the component optimization work. Aquasearch continued their effort on selection of microalgae suitable for CO{sub 2} sequestration. University of Hawaii initiated effort on system optimization of the CO{sub 2} sequestration system.

RECOVERY AND SEQUESTRATION OF CO2 FROM STATIONARY COMBUSTION SYSTEMS BY PHOTOSYNTHESIS OF MICROALGAE

Energy Technology Data Exchange (ETDEWEB)

Dr. T. Nakamura; Dr. C.L. Senior

2001-03-01

Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period from 1 October to 31 December 2000. During this period planning of chemostat experiments at Aquasearch was initiated. These experiments will be used to select microalgae for the photobioreactor demonstrations. An initial survey of techniques for removing CO{sub 2} from coal-fired flue gas was begun. Chemical adsorption using MEA is the most mature technology and looks to be the most economically viable in the near future.

RECOVERY AND SEQUESTRATION OF CO2 FROM STATIONARY COMBUSTION SYSTEMS BY PHOTOSYNTHESIS OF MICROALGAE

Energy Technology Data Exchange (ETDEWEB)

Dr. T. Nakamura; Dr. Miguel Olaizola; Dr. Stephen M. Masutani

2002-01-01

Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report is the summary first year report covering the reporting period 1 October 2000 to 30 September 2001 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work conducted during the previous reporting period, PSI initiated work on the component optimization work. Aquasearch continued their effort on selection of microalgae suitable for CO{sub 2} sequestration. University of Hawaii initiated effort on system optimization of the CO{sub 2} sequestration system.

RECOVERY AND SEQUESTRATION OF CO2 FROM STATIONARY COMBUSTION SYSTEMS BY PHOTOSYNTHESIS OF MICROALGAE

International Nuclear Information System (INIS)

Dr. T. Nakamura; Dr. Miguel Olaizola; Dr. Stephen M. Masutani

2002-01-01

Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO(sub 2) from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 October to 31 December 2001 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work conducted during the previous reporting period, PSI initiated work on the component optimization work. Aquasearch continued their effort on selection of microalgae suitable for CO(sub 2) sequestration. University of Hawaii initiated effort on system optimization of the CO(sub 2) sequestration system

Recent developments on biofuels production from microalgae and macroalgae

DEFF Research Database (Denmark)

Kumar, Kanhaiya; Ghosh, Supratim; Angelidaki, Irini

2016-01-01

and infrastructure requirement. Hydrogen production by microalgae through biophotolysis seems interesting as it directly converts the solar energy into hydrogen. However, the process has not been scaled-up till today. Hydrothermal liquefaction (HTL) is more promising due to handling of wet biomass at moderate......Biofuels from algae are considered as promising alternatives of conventional fossil fuels, as they can eliminate most of the environmental problems. The present study focuses on all the possible avenues of biofuels production through biochemical and thermochemical conversion methods in one place......, bringing together both microalgae and macroalgae on the same platform. It provides a brief overview on the mechanism of different biofuel production from algae. Factors affecting the biofuel process and the associated challenges have been highlighted alongwith analysis of techno-economic study available...

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.)

Effect of alternative mediums on production and proximate composition of the microalgae Chaetoceros muelleri as food in culture of the copepod Acartia sp. Efecto de medios alternativos sobre la producción y composición proximal de la microalga Chaetoceros muelleri como alimento en cultivo del copépodo Acartia sp.

Directory of Open Access Journals (Sweden)

Luis R Martínez-Córdova

2012-03-01

Full Text Available Microalgae Chaetoceros muelleri was cultured in three different mediums consisting on an agricultural fertilizer (Agr-F, aquacultural fertilizer (Aq-F and a conventional medium (F/2, control. These microalgae were later used as natural food to culture the copepod Acartia sp. The productive response and chemical proximate composition of microalgae and copepods were monitored. Growth rate and final cell concentration were higher in microalgae cultured in Agr-F compared to the control. In addition, the final biomass and cellular concentration were also the highest in Agr-F. Microalgae from Agr-F and Aq-F had higher carbohydrate and lower protein contents than those in the control. No differences in lipid and ash contents were observed. Regarding copepod production, higher densities and fecundity indexes were observed for those fed with microalgae previously cultured in Agr-F and Aq-F, compared to the control. The adult-nauplii ratio was also higher in copepods fed on microalgae from Agr-F compared to Aq-F and control. Copepods fed on Agr-F and Aq-F microalgae, had higher protein content compared to those fed on control microalgae; carbohydrates were higher in copepods fed on Agr-F as compared to Aq-F microalgae. No differences in lipid and ash contents were registered. Agr-F and Aq-F were adequate alternative mediums to produce C. muelleri, which produced higher quality microalgae that increased the copepod production.La microalga Chaetoceros muelleri fue cultivada en tres medios diferentes basados en un fertilizante agrícola (Agr-F, un fertilizante acuícola (Aq-F y un medio convencional (F/2, control. Éstas microalgas fueron posteriormente utilizadas como alimento natural para cultivar el copépodo Acartia sp. La respuesta productiva y la composición proximal de las microalgas y copépodos fueron monitoreadas. La tasa de crecimiento y concentración final de células fueron mayores en la microalga cultivada en Agr-F, comparada con el control

Hazard and risk of herbicides for marine microalgae

NARCIS (Netherlands)

Sjollema, S.B.; Martínez-García, G.; van der Geest, H.G.; Kraak, M.H.S.; Booij, P.; Vethaak, A.D.; Admiraal, W.

2014-01-01

Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects

The promising future of microalgae: current status, challenges, and optimization of a sustainable and renewable industry for biofuels, feed, and other products.

Science.gov (United States)

Khan, Muhammad Imran; Shin, Jin Hyuk; Kim, Jong Deog

2018-03-05

Microalgae have recently attracted considerable interest worldwide, due to their extensive application potential in the renewable energy, biopharmaceutical, and nutraceutical industries. Microalgae are renewable, sustainable, and economical sources of biofuels, bioactive medicinal products, and food ingredients. Several microalgae species have been investigated for their potential as value-added products with remarkable pharmacological and biological qualities. As biofuels, they are a perfect substitute to liquid fossil fuels with respect to cost, renewability, and environmental concerns. Microalgae have a significant ability to convert atmospheric CO 2 to useful products such as carbohydrates, lipids, and other bioactive metabolites. Although microalgae are feasible sources for bioenergy and biopharmaceuticals in general, some limitations and challenges remain, which must be overcome to upgrade the technology from pilot-phase to industrial level. The most challenging and crucial issues are enhancing microalgae growth rate and product synthesis, dewatering algae culture for biomass production, pretreating biomass, and optimizing the fermentation process in case of algal bioethanol production. The present review describes the advantages of microalgae for the production of biofuels and various bioactive compounds and discusses culturing parameters.

Absorption of CO2 from modified flue gases of power generation Tarahan chemically using NaOH and Na2CO3 and biologically using microalgae

Science.gov (United States)

Purba, Elida; Agustina, Dewi; Putri Pertama, Finka; Senja, Fita

2018-03-01

hydroxide as a catalyst. The results of in-situ transesterification method cannot be identified. Both microalgae achieved maximum yield at 2% catalyst concentration. Nannochloropsis occulata achieved the highest yield of algal oil that is 88.5%. The highest content of methyl ester from Nannochloropsis occulata was undecanoic acid methyl ester by 55.42% and the result from Tetraselmis chuii was palmitic acid methyl ester by 81.58%.

Contribution of benthic microalgae to the temporal variation in phytoplankton assemblages in a macrotidal system.

Science.gov (United States)

Hernández Fariñas, Tania; Ribeiro, Lourenço; Soudant, Dominique; Belin, Catherine; Bacher, Cédric; Lampert, Luis; Barillé, Laurent

2017-10-01

Suspended marine benthic microalgae in the water column reflect the close relationship between the benthic and pelagic components of coastal ecosystems. In this study, a 12-year phytoplankton time-series was used to investigate the contribution of benthic microalgae to the pelagic system at a site along the French-Atlantic coast. Furthermore, all taxa identified were allocated into different growth forms in order to study their seasonal patterns. The highest contribution of benthic microalgae was observed during the winter period, reaching up to 60% of the carbon biomass in the water column. The haptobenthic growth form showed the highest contribution in terms of biomass, dominant in the fall-winter period when the turbidity and the river flow were high. The epipelic growth form did not follow any seasonal pattern. The epiphytic diatom Licmophora was most commonly found during summer. As benthic microalgae were found in the water column throughout the year, the temporal variation detected in the structure of pelagic assemblages in a macrotidal ecosystem was partly derived from the differentiated contribution of several benthic growth forms. © 2017 Phycological Society of America.

Conteúdo lipídico e composição de ácidos graxos de microalgas expostas aos gases CO2, SO2 e NO Lipid content and fatty acids composition variation of microalgae exposed to CO2, SO2 and NO

Directory of Open Access Journals (Sweden)

Elisangela Martha Radmann

2008-01-01

Full Text Available The objective of the present work was to verify the lipid content and the fatty acid composition of the microalgae Spirulina sp., Scenedesmus obliquus, Synechococcus nidulans and Chlorella vulgaris cultivated in a medium containing CO2, SO2 and NO. The microalga Scenedesmus obliquus presented the highest lipid content (6.18%. For the other microalgae the lipid content ranged from 4.56 to 5.97%. The major monounsaturated fatty acids content was 66.01% for S. obliquus. The PUFA were obtained in major amount by the microalgae Spirulina sp. (29.37% and S. nidulans (29.54%. The palmitoleic acid was in larger amount, with 41.02% concentration (Spirulina sp..

Laboratory scale photobioreactor for high production of microalgae Rhodomonas salina used as food for intensive copepod cultures

DEFF Research Database (Denmark)

Thuy, Minh Vu Thi; Jepsen, Per Meyer; Hansen, Benni Winding

Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems (photobio......Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems...... for copepods (Støttrup and Jensen, 1990; Zhang et al., 2013). Despite the benefit of using R. salina in cultivation of copepods, to our knowledge, there is no report on the production of this microalga at industrial scale to supply sufficient food for mass production of copepods. We intend to conduct the basic...... was cultivated continuously at temperature of 20ºC and salinity of 30ppt in two tubular PBRs with addition of CO2. The experiment was run two times and each PBR in 18 - 30 days. Periodically, the algae were sampled for analyzing the growth, biochemical composition and production. An exponential light model...

A state of the art of metabolic networks of unicellular microalgae and cyanobacteria for biofuel production.

Science.gov (United States)

Baroukh, Caroline; Muñoz-Tamayo, Rafael; Steyer, Jean-Philippe; Bernard, Olivier

2015-07-01

The most promising and yet challenging application of microalgae and cyanobacteria is the production of renewable energy: biodiesel from microalgae triacylglycerols and bioethanol from cyanobacteria carbohydrates. A thorough understanding of microalgal and cyanobacterial metabolism is necessary to master and optimize biofuel production yields. To this end, systems biology and metabolic modeling have proven to be very efficient tools if supported by an accurate knowledge of the metabolic network. However, unlike heterotrophic microorganisms that utilize the same substrate for energy and as carbon source, microalgae and cyanobacteria require light for energy and inorganic carbon (CO2 or bicarbonate) as carbon source. This double specificity, together with the complex mechanisms of light capture, makes the representation of metabolic network nonstandard. Here, we review the existing metabolic networks of photoautotrophic microalgae and cyanobacteria. We highlight how these networks have been useful for gaining insight on photoautotrophic metabolism. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Impact of feed supplementation with different omega-3 rich microalgae species on enrichment of eggs of laying hens.

Science.gov (United States)

Lemahieu, Charlotte; Bruneel, Charlotte; Termote-Verhalle, Romina; Muylaert, Koenraad; Buyse, Johan; Foubert, Imogen

2013-12-15

Four different omega-3 rich autotrophic microalgae, Phaeodactylum tricornutum, Nannochloropsis oculata, Isochrysis galbana and Chlorella fusca, were supplemented to the diet of laying hens in order to increase the level of omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) in egg yolk. The microalgae were supplemented in two doses: 125 mg and 250 mg extra n-3 PUFA per 100g feed. Supplementing these microalgae resulted in increased but different n-3 LC-PUFA levels in egg yolk, mainly docosahexaenoic acid enrichment. Only supplementation of Chlorella gave rise to mainly α-linolenic acid enrichment. The highest efficiency of n-3 LC-PUFA enrichment was obtained by supplementation of Phaeodactylum and Isochrysis. Furthermore, yolk colour shifted from yellow to a more intense red colour with supplementation of Phaeodactylum, Nannochloropsis and Isochrysis, due to transfer of carotenoids from microalgae to eggs. This study shows that besides Nannochloropsis other microalgae offer an alternative to current sources for enrichment of hen eggs. Copyright © 2013 Elsevier Ltd. All rights reserved.

Carotenoids, Phenolic Compounds and Tocopherols Contribute to the Antioxidative Properties of Some Microalgae Species Grown on Industrial Wastewater

Science.gov (United States)

Safafar, Hamed; van Wagenen, Jonathan; Møller, Per; Jacobsen, Charlotte

2015-01-01

This study aimed at investigating the potential of microalgae species grown on industrial waste water as a new source of natural antioxidants. Six microalgae from different classes, including Phaeodactylum sp. (Bacillariophyceae), Nannochloropsis sp. (Eustigmatophyceae), Chlorella sp., Dunaniella sp., and Desmodesmus sp. (Chlorophyta), were screened for their antioxidant properties using different in vitro assays. Natural antioxidants, including pigments, phenolics, and tocopherols, were measured in methanolic extracts of microalgae biomass. Highest and lowest concentrations of pigments, phenolic compounds, and tocopherols were found in Desmodesmus sp. and Phaeodactylum tricornuotom microalgae species, respectively. The results of each assay were correlated to the content of natural antioxidants in microalgae biomass. Phenolic compounds were found as major contributors to the antioxidant activity in all antioxidant tests while carotenoids were found to contribute to the 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity, ferrous reduction power (FRAP), and ABTS-radical scavenging capacity activity. Desmodesmus sp. biomass represented a potentially rich source of natural antioxidants, such as carotenoids (lutein), tocopherols, and phenolic compounds when cultivated on industrial waste water as the main nutrient source. PMID:26690454

Impact of procedural steps and cryopreservation agents in the cryopreservation of chlorophyte microalgae.

Directory of Open Access Journals (Sweden)

Tony V L Bui

Full Text Available The maintenance of traditional microalgae collections based on liquid and solid media is labour intensive, costly and subject to contamination and genetic drift. Cryopreservation is therefore the method of choice for the maintenance of microalgae culture collections, but success is limited for many species. Although the mechanisms underlying cryopreservation are understood in general, many technical variations are present in the literature and the impact of these are not always elaborated. This study describes two-step cryopreservation processes in which 3 microalgae strains representing different cell sizes were subjected to various experimental approaches to cryopreservation, the aim being to investigate mechanistic factors affecting cell viability. Sucrose and dimethyl sulfoxide (DMSO were used as cryoprotectants. They were found to have a synergistic effect in the recovery of cryopreserved samples of many algal strains, with 6.5% being the optimum DMSO concentration. The effect of sucrose was shown to be due to improved cell survival and recovery after thawing by comparing the effect of sucrose on cell viability before or after cryopreservation. Additional factors with a beneficial effect on recovery were the elimination of centrifugation steps (minimizing cell damage, the reduction of cell concentration (which is proposed to reduce the generation of toxic cell wall components and the use of low light levels during the recovery phase (proposed to reduce photooxidative damage. The use of the best conditions for each of these variables yielded an improved protocol which allowed the recovery and subsequent improved culture viability of a further 16 randomly chosen microalgae strains. These isolates included species from Chlorellaceae, Palmellaceae, Tetrasporaceae, Palmellopsis, Scenedesmaceae and Chlamydomonadaceae that differed greatly in cell diameter (3-50 µm, a variable that can affect cryopreservation success. The collective improvement

Technical Note: Development of a Photobioreactor for Microalgae ...

African Journals Online (AJOL)

In view of the technical and biological limitations of open pond systems, a study was conducted to develop a cost-effective experimental photobioreactor that would permit efficient cultivation of microalgae for biodiesel production. The photobioreactor was developed using low cost materi- als, cylindrical translucent tubes ...

Cultivation of microalgae in a high irradiance area

NARCIS (Netherlands)

Cuaresma, M.

2011-01-01

Microalgae are a promising source of high-value products (i.e. carotenoids, ω-3 fatty acids), as well as feedstocks for food, bulk chemicals and biofuels. Industrial production is, however, still limited because the technology needs further development. One of the main bottlenecks is the

Preliminary Study on the Location Selection of Microalgae Cultivation In Nusa Tenggara Region As A Potential Feedstock For Bioavtur

Science.gov (United States)

Anggraini, Citrae Permata Kusuma; Sasongko, Nugroho Adi; Kuntjoro, Yanif Dwi

2018-02-01

NTT is a province located in strategic areas between Bali and South Sulawesi which has economic growth 5,08% in 2016. This causes air transportation in NTT to grow rapidly so the need for avtur is increased by 6% per year. To meet the needs of avtur in NTT would require energy diversification with bioavtur development in which one of them comes from microalgae. The content of lipid and hydrocarbon in microalgae can be used as a source of bioavtur feedstock. The suitability of location for cultivation will influence the success of microalgae cultivation that will be used as a source of bioavtur feedstock. The purpose of this research is to choose the best location for microalgae cultivation in NTT by AHP method. The criteria used in this research are nutrient, water and technology. Sub criteria of nutrient elements are coal power plant emission, cement industry emission and synthetic fertilizers, sub criteria from water that is sea water, brackish water and fresh water, while sub criteria of technology are Photobioreactor, Open Raceway Pond and membrane. The result of AHP analysis shows the selection of microalgae cultivation location in Kupang with the weight of 0.308, with the source of nutrient derived from coal power plant emission, the type of water used is sea water and the technology used is Photobioreactor. Microalgae species used were Nannochloropsis sp with a lipid content of 31-68%. Based on the author assumption, microalgae have the productivity for bioavtur manufacture which amount of 24.489kL/ha/ yr. That can be used to meet the needs of 2% avtur in NTT which amount of 1.052,22 kL/yr and the area requirement for microalgae cultivation is 2,14 hectare.

A model for utilizing industrial off-gas to support microalgae cultivation for biodiesel in cold climates

International Nuclear Information System (INIS)

Laamanen, Corey A.; Shang, Helen; Ross, Gregory M.; Scott, John A.

2014-01-01

Highlights: • Development of a model to assess process-coupled algae production in cold climates. • Algae growth temperatures in open tanks can be maintained with industrial off-gas. • Indirect and direct heat application from industrial off-gasses are assessed. • CO 2 -rich off-gas can be bubbled into algae tanks to provide a carbon source. • A nickel smelter’s off-gas is used to demonstrate how waste heat can be repurposed. - Abstract: Lipids produced by microalgae are a promising biofuel feedstock. However, as most commercial mass production of microalgae is in open raceway ponds it is generally considered only a practical option in regions where year-round ambient temperatures remain above 15 °C. To address this issue it has been proposed to couple microalgae production with industries that produce large amounts of waste heat and carbon dioxide (CO 2 ). The CO 2 would provide a carbon source for the microalgae and the waste heat would allow year-round cultivation to be extended to regions that experience seasonal ambient temperatures well below 15 °C. To demonstrate this concept, a dynamic model has been constructed that predicts the impact on algal pond temperature from both bubbled-in off-gas and heat indirectly recovered from off-gas. Simulations were carried out for a variety of global locations using the quantity off-gas and waste energy from a smelter’s operations to determine the volume of microalgae that could be maintained above 15 °C. The results demonstrate the feasibility of year-round microalgae production in climates with relatively cold winter seasons

Evaluation of Marine Microalga Diacronema vlkianum Biomass Fatty Acid Assimilation in Wistar Rats

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Cristina de Mello-Sampayo

2017-07-01

Full Text Available Diacronema vlkianum is a marine microalgae for which supposed health promoting effects have been claimed based on its phytochemical composition. The potential use of its biomass as health ingredient, including detox-shakes, and the lack of bioavailability studies were the main concerns. In order to evaluate the microalgae-biomass assimilation and its health-benefits, single-dose (CD1-mice studies were followed by 66-days repeated-dose study in Wistar rats with the highest tested single-dose of microalgae equivalent to 101 mg/kg eicosapentaenoic acid + docosahexaenoic acid (EPA+DHA. Microalgae-supplementation modulated EPA and docosapentaenoic acid enrichment at arachidonic acid content expenditure in erythrocytes and liver, while increasing EPA content of heart and adipose tissues of rats. Those fatty acid (FA changes confirmed the D. vlkianum-biomass FA assimilation. The principal component analyses discriminated brain from other tissues, which formed two other groups (erythrocytes, liver, and heart separated from kidney and adipose tissues, pointing to a distinct signature of FA deposition for the brain and for the other organs. The improved serum lipid profile, omega-3 index and erythrocyte plasticity support the cardiovascular benefits of D. vlkianum. These results bolster the potential of D. vlkianum-biomass to become a “heart-healthy” food supplement providing a safe and renewable source of bioavailable omega-3 FA.

A tangled tale of two teal: Population history of the grey Anas gracilis and chestnut teal a. castanea of Australia

Science.gov (United States)

Joseph, L.; Adcock, G.J.; Linde, C.; Omland, K.E.; Heinsohn, R.; Terry, Chesser R.; Roshier, D.

2009-01-01

Two Australian species of teal (Anseriformes: Anatidae: Anas), the grey teal Anas gracilis and the chestnut teal A. castanea, are remarkable for the zero or near-zero divergence recorded between them in earlier surveys of mitochondrial DNA (mtDNA) diversity. We confirmed this result through wider geographical and population sampling as well as nucleotide sampling in the more rapidly evolving mtDNA control region. Any data set where two species share polymorphism as is the case here can be explained by a model of gene flow through hybridization on one hand or by incomplete lineage sorting on the other hand. Ideally, analysis of such shared polymorphism would simultaneously estimate the likelihood of both phenomena. To do this, we used the underlying principle of the IMa package to explore ramifications to understanding population histories of A. gracilis and A. castanea. We cannot reject that hybridization occurs between the two species but an equally or more plausible finding for their nearly zero divergence is incomplete sorting following very recent divergence between the two, probably in the mid-late Pleistocene. Our data add to studies that explore intermediate stages in the evolution of reciprocal monophyly and paraphyletic or polyphyletic relationships in mtDNA diversity among widespread Australian birds. ?? 2009 J. Avian Biol.

CO2 gasification of microalgae (N. Oculata – A thermodynamic study

Directory of Open Access Journals (Sweden)

Adnan Muflih Arisa

2018-01-01

Full Text Available A new model of CO2 gasification has been developed in the Aspen Plus. The potential of microalgae (N. oculata for CO2 gasification also has been investigated. The present gasification process utilizes the CO2 at atmospheric pressure as the gasifying agent. The steam is also injected to the gasification to enhance the H2 production. The composition of the producer gas and gasification system efficiency (GSE are used for performance evaluation. It is found that the CO2 gasification of microalgae produces a producer gas with a high concentration of CO and H2. The GSE indicates that the process works at high performance.

Kinematics of flagellar swimming in Euglena gracilis: Helical trajectories and flagellar shapes.

Science.gov (United States)

Rossi, Massimiliano; Cicconofri, Giancarlo; Beran, Alfred; Noselli, Giovanni; DeSimone, Antonio

2017-12-12

The flagellar swimming of euglenids, which are propelled by a single anterior flagellum, is characterized by a generalized helical motion. The 3D nature of this swimming motion, which lacks some of the symmetries enjoyed by more common model systems, and the complex flagellar beating shapes that power it make its quantitative description challenging. In this work, we provide a quantitative, 3D, highly resolved reconstruction of the swimming trajectories and flagellar shapes of specimens of Euglena gracilis We achieved this task by using high-speed 2D image recordings taken with a conventional inverted microscope combined with a precise characterization of the helical motion of the cell body to lift the 2D data to 3D trajectories. The propulsion mechanism is discussed. Our results constitute a basis for future biophysical research on a relatively unexplored type of eukaryotic flagellar movement. Copyright © 2017 the Author(s). Published by PNAS.

Potential of sponges and microalgae for marine biotechnology

NARCIS (Netherlands)

Wijffels, R.H.

2008-01-01

Marine organisms can be used to produce several novel products that have applications in new medical technologies, in food and feed ingredients and as biofuels. In this paper two examples are described: the development of marine drugs from sponges and the use of microalgae to produce bulk chemicals

Enhanced performance of the microalga Chlorella sorokiniana remotely induced by the plant growth-promoting bacteria Azospirillum brasilense and Bacillus pumilus

Science.gov (United States)

Amavizca, Edgar; Bashan, Yoav; Ryu, Choong-Min; Farag, Mohamed A.; Bebout, Brad M.; de-Bashan, Luz E.

2017-01-01

Remote effects (occurring without physical contact) of two plant growth-promoting bacteria (PGPB) Azospirillum brasilense Cd and Bacilus pumilus ES4 on growth of the green microalga Chlorella sorokiniana UTEX 2714 were studied. The two PGPB remotely enhanced the growth of the microalga, up to six-fold, and its cell volume by about three-fold. In addition to phenotypic changes, both bacteria remotely induced increases in the amounts of total lipids, total carbohydrates, and chlorophyll a in the cells of the microalga, indicating an alteration of the microalga’s physiology. The two bacteria produced large amounts of volatile compounds, including CO2, and the known plant growth-promoting volatile 2,3-butanediol and acetoin. Several other volatiles having biological functions in other organisms, as well as numerous volatile compounds with undefined biological roles, were detected. Together, these bacteria-derived volatiles can positively affect growth and metabolic parameters in green microalgae without physical attachment of the bacteria to the microalgae. This is a new paradigm on how PGPB promote growth of microalgae which may serve to improve performance of Chlorella spp. for biotechnological applications. PMID:28145473

Spectroscopic investigation of ionizing-radiation tolerance of a Chlorophyceae green micro-alga

Energy Technology Data Exchange (ETDEWEB)

Farhi, E; Compagnon, E; Marzloff, V; Ollivier, J; Boisson, A M; Natali, F; Russo, D [Institut Laue-Langevin, BP 156, 38042 Grenoble cedex 9 (France); Rivasseau, C; Gromova, M; Bligny, R [CEA, Laboratoire de Physiologie Cellulaire Vegetale, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France); Coute, A [Museum National d' Histoire Naturelle, Laboratoire de Cryptogamie, 2 rue Buffon, 75005 Paris (France)

2008-03-12

Micro-organisms living in extreme environments are captivating in the peculiar survival processes they have developed. Deinococcus radiodurans is probably the most famous radio-resistant bacteria. Similarly, a specific ecosystem has grown in a research reactor storage pool, and has selected organisms which may sustain radiative stress. An original green micro-alga which was never studied for its high tolerance to radiations has been isolated. It is the only autotrophic eukaryote that develops in this pool, although contamination possibilities coming from outside are not unusual. Studying what could explain this irradiation tolerance is consequently very interesting. An integrative study of the effects of irradiation on the micro-algae physiology, metabolism, internal dynamics, and genomics was initiated. In the work presented here, micro-algae were stressed with irradiation doses up to 20 kGy (2 Mrad), and studied by means of nuclear magnetic resonance, looking for modifications in the metabolism, and on the IN13 neutron backscattering instrument at the ILL, looking for both dynamics and structural macromolecular changes in the cells.

Spectroscopic investigation of ionizing-radiation tolerance of a Chlorophyceae green micro-alga

International Nuclear Information System (INIS)

Farhi, E; Compagnon, E; Marzloff, V; Ollivier, J; Boisson, A M; Natali, F; Russo, D; Rivasseau, C; Gromova, M; Bligny, R; Coute, A

2008-01-01

Micro-organisms living in extreme environments are captivating in the peculiar survival processes they have developed. Deinococcus radiodurans is probably the most famous radio-resistant bacteria. Similarly, a specific ecosystem has grown in a research reactor storage pool, and has selected organisms which may sustain radiative stress. An original green micro-alga which was never studied for its high tolerance to radiations has been isolated. It is the only autotrophic eukaryote that develops in this pool, although contamination possibilities coming from outside are not unusual. Studying what could explain this irradiation tolerance is consequently very interesting. An integrative study of the effects of irradiation on the micro-algae physiology, metabolism, internal dynamics, and genomics was initiated. In the work presented here, micro-algae were stressed with irradiation doses up to 20 kGy (2 Mrad), and studied by means of nuclear magnetic resonance, looking for modifications in the metabolism, and on the IN13 neutron backscattering instrument at the ILL, looking for both dynamics and structural macromolecular changes in the cells

Efect of Gamma 60Co Irradiation on The Growth, Lipid Content and Fatty Acid Composition of Botryococcus sp. Microalgae

Directory of Open Access Journals (Sweden)

Dini Ermavitalini

2017-04-01

Full Text Available Botryococcus sp. is one of microalgae species that has a high lipid content as much as 75% of their dry weight. But, lipid production by microalgae is regulated by their environmental condition (pH, light, temperature, nutrition, etc. Mutagenesis induced by Gamma 60Co irradiation can be utilized to alter the Botryococcus sp. genetic to get microalgae mutant strain that can produce a higher lipid content than the wild strain. Botryococcus sp. was irradiated with different doses of gamma ray of 60Co  (0, 2, 4, 6, and 10 Gy,  and the effect  on the growth, lipid content, and fatty acid composition of microalgae were observed. Research design used is random complete (RAL with 95 %  confident level for quantitive analysis based on the biomass and lipid contents. More over fatty acid composition was analyzed by Gas Cromatography-Mass Spectrometry (GC-MS. Results showed that Gamma irradiated gave an effect on growth and lipid content of Botryococcus sp. But between the control treatment (0 Gy with microalgae irradiated dose of 2 Gy, 4 Gy and 6 Gy were not significantly different. Whereas between the control with 10 Gy irradiated was significantly different. The highest biomassa and lipid content are found in 10 Gy irradiated microalgae with 0.833 gram biomass and 41% lipid content. Fatty acid profile of Botryococcus sp. control has 6 fatty acids while 10 Gy irradiated microalgae has 12 fatty acids, with the long-chain fatty acids increased, whereas short-chain fatty acids decreased.

Estado actual de las empresas productoras de microalgas destinadas a alimentos y suplementos alimenticios en América Latina

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Luis Daniel Martínez Angulo

2017-12-01

Full Text Available Las microalgas resultan de interés en la producción de alimentos y suplementos debido a su riqueza de nutrientes. Esta revisión tiene como objetivo recopilar información actual sobre el estado de empresas de mediana y gran escala, productoras de biomasa y bioproductos microalgales comercializados como alimento y suplemento alimenticio en América Latina, con el fin de conocer el nivel de desarrollo en la región. El país con mayor cantidad de empresas productoras de alimentos a base de microalgas es Brasil (6, seguido de México, Perú, Chile (2, Ecuador y Cuba (1. El sistema de cultivo más común empleado por empresas latinoamericanas en el comercio de microalgas es el abierto. El organismo más utilizado en productos alimenticios a base de microalgas en Latinoamérica corresponde al género Spirulina. Se ha investigado sobre la composición bioquímica de más de 10 especies de microalgas, a escala de laboratorio. Las microalgas son fuente importante de proteínas y de ácidos grasos del tipo omega-3, así como de vitaminas y minerales. Se evidencia el potencial que tiene Latinoamérica para el desarrollo de nuevas tecnologías de sistemas de cultivo y productos alimenticios a base de microalgas, como alimento para la población como para la exportación. Sin embargo, se requiere de un gran esfuerzo tanto del sector privado como del público para alcanzar los fines.

Microalgae for Bioenergy; Key Technology Nodes

Czech Academy of Sciences Publication Activity Database

Maléterová, Ywetta; Kaštánek, František; Rousková, Milena; Matějková, Martina; Kaštánek, P.; Šolcová, Olga

2015-01-01

Roč. 2015, č. 2015 (2015), s. 597618 ISSN 1537-744X R&D Projects: GA MŠk LJ12002 Institutional support: RVO:67985858 Keywords : microalgae * oil production * water recycling Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.219, year: 2013 http://apps.webofknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=14&SID=V2kH1WLyceq9ctvzW8I&page=1&doc=1

Phototrophic pigment production with microalgae: biological constraints and opportunities

NARCIS (Netherlands)

Mulders, K.J.M.; Lamers, P.P.; Martens, D.E.; Wijffels, R.H.

2014-01-01

There is increasing interest in naturally produced colorants, and microalgae represent a bio-technologically interesting source due to their wide range of colored pigments, including chlorophylls (green), carotenoids (red, orange and yellow), and phycobiliproteins (red and blue). However, the

Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae.

NARCIS (Netherlands)

Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

2013-01-01

Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments. Cyanobacteria are promising host organisms

Potential pyrolysis pathway assessment for microalgae-based aviation fuel based on energy conversion efficiency and life cycle

International Nuclear Information System (INIS)

Guo, Fang; Wang, Xin; Yang, Xiaoyi

2017-01-01

Highlights: • High lipid content in microalgae increases energy conversion efficiency. • Indirect pathway has the highest mass ratio, energy ratio and energy efficiency. • The Isochrysis indirect pathway produces most kerosene component precursor. • The Isochrysis indirect pyrolysis pathway shows the best performance in LCA. - Abstract: Although the research of microalgae pyrolysis has been conducted for many years, there is a lack of investigations on energy efficiency and life cycle assessment. In this study, we investigated the biocrude yield and energy efficiency of direct pyrolysis, microalgae residue pyrolysis after lipid extraction (indirect pyrolysis), and different microalgae co-pyrolysis. This research also investigated the life cycle assessment of the three different pyrolysis pathways. A system boundary of Well-to-Wake (WTWa) was defined and included sub-process models, such as feedstock production, fuel production and pump-to-wheels (PTW) stages. The pathway of Isochrysis indirect pyrolysis shows the best performance in the mass ratio and energy ratio, produces the most kerosene component precursor, has the lowest WTWa total energy input, fossil fuel consumption and greenhouse gas emissions, and resultes in the best energy efficiency. All the evidence indicates that Isochrysis R2 pathway is a potential and optimal pyrolysis pathway to liquid biofuels. The mass ratio of pyrolysis biocrude is shown to be the decisive factor for different microalgae species. The sensitivity analysis results also indicates that the life cycle indicators are particularly sensitive to the mass ratio of pyrolysis biocrude for microalgae-based hydrotreated pyrolysis aviation fuel.

A multilayer concentric filter device to diminish clogging for separation of particles and microalgae based on size.

Science.gov (United States)

Chen, Chih-Chung; Chen, Yu-An; Liu, Yi-Ju; Yao, Da-Jeng

2014-04-21

Microalgae species have great economic importance; they are a source of medicines, health foods, animal feeds, industrial pigments, cosmetic additives and biodiesel. Specific microalgae species collected from the environment must be isolated for examination and further application, but their varied size and culture conditions make their isolation using conventional methods, such as filtration, streaking plate and flow cytometric sorting, labour-intensive and costly. A separation device based on size is one of the most rapid, simple and inexpensive methods to separate microalgae, but this approach encounters major disadvantages of clogging and multiple filtration steps when the size of microalgae varies over a wide range. In this work, we propose a multilayer concentric filter device with varied pore size and is driven by a centrifugation force. The device, which includes multiple filter layers, was employed to separate a heterogeneous population of microparticles into several subpopulations by filtration in one step. A cross-flow to attenuate prospective clogging was generated by altering the rate of rotation instantly through the relative motion between the fluid and the filter according to the structural design of the device. Mixed microparticles of varied size were tested to demonstrate that clogging was significantly suppressed due to a highly efficient separation. Microalgae in a heterogeneous population collected from an environmental soil collection were separated and enriched into four subpopulations according to size in a one step filtration process. A microalgae sample contaminated with bacteria and insect eggs was also tested to prove the decontamination capability of the device.

Effect of Light/Dark Regimens on Hydrogen Production by Tetraselmis subcordiformis Coupled with an Alkaline Fuel Cell System.

Science.gov (United States)

Guo, Zhen; Li, Ying; Guo, Haiyan

2017-12-01

To improve the photoproduction of hydrogen (H 2 ) by a green algae-based system, the effect of light/dark regimens on H 2 photoproduction regulated by carbonyl cyanide m-chlorophenylhydrazone (CCCP) was investigated. A fuel cell was integrated into a photobioreactor to allow online monitoring of the H 2 evolution rate and decrease potential H 2 feedback inhibition by consuming the generated H 2 in situ. During the first 15 h of H 2 evolution, the system was subjected to dark treatment after initial light illumination (L/D = 6/9 h, 9/6 h, and 12/3 h). After the dark period, all systems were again exposed to light illumination until H 2 evolution stopped. Two peaks were observed in the H 2 evolution rate under all three light/dark regimens. Additionally, a high H 2 yield of 126 ± 10 mL L -1 was achieved using a light/dark regimen of L 9 h/D 6 h/L until H 2 production ceased, which was 1.6 times higher than that obtained under continuous illumination. H 2 production was accompanied by some physiological and morphological changes in the cells. The results indicated that light/dark regimens improved the duration and yield of H 2 photoproduction by the CCCP-regulated process of Tetraselmis subcordiformis.

Recovery and Sequestration of CO2 from Stationary Combustion Systems by Photosynthesis of Microalgae

Energy Technology Data Exchange (ETDEWEB)

T. Nakamura; C.L. Senior

2005-04-01

Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 October 2000 to 31 March 2005 in which PSI, Aquasearch and University of Hawaii conducted their tasks. This report discusses results of the work pertaining to five tasks: Task 1--Supply of CO2 from Power Plant Flue Gas to Photobioreactor; Task 2--Selection of Microalgae; Task 3--Optimization and Demonstration of Industrial Scale Photobioreactor; Task 4--Carbon Sequestration System Design; and Task 5--Economic Analysis. Based on the work conducted in each task summary conclusion is presented.

Strains of toxic and harmful microalgae, from waste water, marine, brackish and fresh water.

Science.gov (United States)

Rodríguez-Palacio, M C; Crisóstomo-Vázquez, L; Alvarez-Hernández, S; Lozano-Ramírez, C

2012-01-01

Some microalgae are economically important in Mexico and the world because they can be potentially toxic. Algal explosive population growths are named harmful algal blooms and are frequently recorded in Mexico. The authors set up potentially toxic microalgae cultures from the Gulf of Mexico (Garrapatas tideland, Barberena river, Carpintero lagoon in Tamaulipas State; Chalchoapan and Catemaco lakes in Veracruz State), from the Mexican Pacific Ocean, Guerrero, Colima and Michoacán States, and from interior water bodies such as Vicente Aguirre dam, Chapultepec lake and several waste water treatment plants. This research is about the diversity and abundance of phytoplankton in relation a specific site because of harmful algal bloom events. Microalgae cultures are useful in order to solve taxonomic problems, to know life cycles, molecular studies, for the study of toxic species, and the isolation of useful metabolites. The cultures for this research are clonal, non-axenic, semi-continuous, 12:12 light/dark photoperiod, 20 ± 1 °C temperature and 90.5 µmol m(-2)s(-1) illumination. Four different culture media were used. This collection is open to the worldwide scientific community as a source of organisms in controlled conditions that can be used as a useful tool for microalgae research work.

Study of cultivation and growth rate kinetic for mixed cultures of local microalgae as third generation (G-3) bioethanol feedstock in thin layer photobioreactor

Science.gov (United States)

Prihastuti Yuarrina, Wahyu; Surya Pradana, Yano; Budiman, Arief; Majid, Akmal Irfan; Indarto; Agus Suyono, Eko

2018-05-01

The increasing use of fossil fuels causes the depletion in supply and contributes to climate change by GHG emissions into the atmosphere. Microalgae indicate as renewable and sustainable energy sources as they have a high potential for producing large amounts of biomass for third-generation biofuels (bioethanol and biodiesel) feedstock. However, there are several parameters which should be considered for microalgae cultivation, such as environmental conditions, medium composition and microalgae species. The aim of this research was to study cultivation of mixed microalgae cultures (Glagah consortium and Arthrospira maxima) in a thin layer photobioreactor. Farmpion medium, Bold’s Basal Medium (BBM) and Thoriq Eko Arief (TEA) medium were investigated as cultivation medium for bioethanol feedstock for 7 days. The results showed that the highest dry weight concentration of microalgae was in Farmpion medium (0.35 mg/ml) and the highest carbohydrate concentration of microalgae was in BBM (0.14 mg/ml). Thus, the optimum medium of microalgae cultivation for bioethanol feedstock was BBM because of the highest carbohydrate-dry weight ratio (0.88). In addition, mathematical approach by using Contois model was used to find out the growth rate of microalgae cultivation in each medium.

Biodiesel production from Spirulina microalgae feedstock using direct transesterification near supercritical methanol condition.

Science.gov (United States)

Mohamadzadeh Shirazi, Hamed; Karimi-Sabet, Javad; Ghotbi, Cyrus

2017-09-01

Microalgae as a candidate for production of biodiesel, possesses a hard cell wall that prevents intracellular lipids leaving out from the cells. Direct or in situ supercritical transesterification has the potential for destruction of microalgae hard cell wall and conversion of extracted lipids to biodiesel that consequently reduces the total energy consumption. Response surface methodology combined with central composite design was applied to investigate process parameters including: Temperature, Time, Methanol-to-dry algae, Hexane-to-dry algae, and Moisture content. Thirty-two experiments were designed and performed in a batch reactor, and biodiesel efficiency between 0.44% and 99.32% was obtained. According to fatty acid methyl ester yields, a quadratic experimental model was adjusted and the significance of parameters was evaluated using analysis of variance (ANOVA). Effects of single and interaction parameters were also interpreted. In addition, the effect of supercritical process on the ultrastructure of microalgae cell wall using scanning electron spectrometry (SEM) was surveyed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Organic Solvents on Microalgae Growth, Metabolism and Industrial Bioproduct Extraction: A Review.

Science.gov (United States)

Miazek, Krystian; Kratky, Lukas; Sulc, Radek; Jirout, Tomas; Aguedo, Mario; Richel, Aurore; Goffin, Dorothee

2017-07-04

In this review, the effect of organic solvents on microalgae cultures from molecular to industrial scale is presented. Traditional organic solvents and solvents of new generation-ionic liquids (ILs), are considered. Alterations in microalgal cell metabolism and synthesis of target products (pigments, proteins, lipids), as a result of exposure to organic solvents, are summarized. Applications of organic solvents as a carbon source for microalgal growth and production of target molecules are discussed. Possible implementation of various industrial effluents containing organic solvents into microalgal cultivation media, is evaluated. The effect of organic solvents on extraction of target compounds from microalgae is also considered. Techniques for lipid and carotenoid extraction from viable microalgal biomass (milking methods) and dead microalgal biomass (classical methods) are depicted. Moreover, the economic survey of lipid and carotenoid extraction from microalgae biomass, by means of different techniques and solvents, is conducted.

Probing the elastic response of microalga Scenedesmus dimorphus in dry and aqueous environments through atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Warren, K. M.; Mpagazehe, J. N.; Higgs, C. F., E-mail: prl@andrew.cmu.edu, E-mail: higgs@andrew.cmu.edu [Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); LeDuc, P. R., E-mail: prl@andrew.cmu.edu, E-mail: higgs@andrew.cmu.edu [Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); Departments of Biomedical Engineering and Biological Sciences, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213 (United States)

2014-10-20

With the re-emergence of microalgae as a replacement feedstock for petroleum-derived oils, researchers are working to understand its chemical and mechanical behavior. In this work, the mechanical properties of microalgae, Scenedesmus dimorphus, were investigated at the subcellular level to determine the elastic response of cells that were in an aqueous and dried state using nano-scale indentation through atomic force microscopy. The elastic modulus of single-celled S. dimorphus cells increased over tenfold from an aqueous state to a dried state, which allows us to better understand the biophysical response of microalgae to stress.

Probing the elastic response of microalga Scenedesmus dimorphus in dry and aqueous environments through atomic force microscopy

International Nuclear Information System (INIS)

Warren, K. M.; Mpagazehe, J. N.; Higgs, C. F.; LeDuc, P. R.

2014-01-01

With the re-emergence of microalgae as a replacement feedstock for petroleum-derived oils, researchers are working to understand its chemical and mechanical behavior. In this work, the mechanical properties of microalgae, Scenedesmus dimorphus, were investigated at the subcellular level to determine the elastic response of cells that were in an aqueous and dried state using nano-scale indentation through atomic force microscopy. The elastic modulus of single-celled S. dimorphus cells increased over tenfold from an aqueous state to a dried state, which allows us to better understand the biophysical response of microalgae to stress.

Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae

NARCIS (Netherlands)

Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

2013-01-01

Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments.Cyanobacteria are promising host organisms for

Investigation on novel raceway pond with inclined paddle wheels through simulation and microalgae culture experiments.

Science.gov (United States)

Zeng, Fanxue; Huang, Jianke; Meng, Chen; Zhu, Fachao; Chen, Jianpei; Li, Yuanguang

2016-01-01

The open raceway ponds are nowadays the most used large-scale reactors for microalgae culture. To avoid the stacking of microalgae, the paddle wheels are the most widely used to circulate and mix the culture medium. In this paper, a numerical simulation using computational fluid dynamics (CFD) was used to investigate the hydrodynamic characteristics of open raceway ponds with different types of paddle wheels (the traditional paddle wheels and the novel paddle wheels with specially inclined angle of the blades). The particle image velocimetry (PIV) was used to validate the reliability of the CFD model. The CFD simulation results showed that the novel raceway pond with 15° inclined angle of the blades had the best mixing efficiency under the same power consumption. Lastly, the results of microalgae culture experiments showed that the growth rates of Chlorella pyrenoidosa in the novel raceway pond with 15° inclined angle of the blades were higher than those in the traditional reactor. The results of the culture experiments and CFD simulations were identical with each other. Therefore, a novel paddle wheel with 15° inclined angle of the blades was obtained for better microalgae cultivation.

Biodiesel Production from Selected Microalgae Strains and Determination of its Properties and Combustion Specific Characteristics

Directory of Open Access Journals (Sweden)

N. Kokkinos

2015-11-01

Full Text Available Biofuels are gaining importance as significant substitutes for the depleting fossil fuels. Recent focus is on microalgae as the third generation feedstock. In the present research work, two indigenous fresh water and two marine Chlorophyte strains have been cultivated successfully under laboratory conditions using commercial fertilizer (Nutrileaf 30-10-10, initial concentration=70 g/m3 as nutrient source. Gas chromatographic analysis data showed that microalgae biodiesel obtained from Chlorophyte strains biomass were composed of fatty acid methyl esters. The produced microalgae biodiesel achieved a range of 2.2 - 10.6 % total lipid content and an unsaturated FAME content between 49 mol% and 59 mol%. The iodine value, the cetane number, the cold filter plugging point, the oxidative stability as well as combustion specific characteristics of the final biodiesels were determined based on the compositions of the four microalgae strains. The calculated biodiesel properties compared then with the corresponding properties of biodiesel from known vegetable oils, from other algae strains and with the specifications in the EU (EN 14214 and US (ASTM D6751 standards. The derived biodiesels from indigenous Chlorophyte algae were significantly comparable in quality with other biodiesels.

Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes.

Science.gov (United States)

Chen, Ching-Lung; Huang, Chien-Chang; Ho, Kao-Chia; Hsiao, Ping-Xuan; Wu, Meng-Shan; Chang, Jo-Shu

2015-10-01

Although producing biodiesel from microalgae seems promising, there is still a lack of technology for the quick and cost-effective conversion of biodiesel from wet microalgae. This study was aimed to develop a novel microalgal biodiesel producing method, consisting of an open system of microwave disruption, partial dewatering (via combination of methanol treatment and low-speed centrifugation), oil extraction, and transesterification without the pre-removal of the co-solvent, using Chlamydomonas sp. JSC4 with 68.7 wt% water content as the feedstock. Direct transesterification with the disrupted wet microalgae was also conducted. The biomass content of the wet microalgae increased to 56.6 and 60.5 wt%, respectively, after microwave disruption and partial dewatering. About 96.2% oil recovery was achieved under the conditions of: extraction temperature, 45°C; hexane/methanol ratio, 3:1; extraction time, 80 min. Transesterification of the extracted oil reached 97.2% conversion within 15 min at 45°C and 6:1 solvent/methanol ratio with simultaneous Chlorophyll removal during the process. Nearly 100% biodiesel conversion was also obtained while conducting direct transesterification of the disrupted oil-bearing microalgal biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.