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Sample records for platensis utilizing perpendicular

  1. Production and utilization of the blue-green alga Spirulina in India. [Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Becker, E.W.; Venkataraman, L.V.

    1984-01-01

    Initiated by Indo-German cooperation on large-scale cultivation of micro-algae, aspects of production, processing and utilization of the blue-green alga (cyanobacterium) Spirulina platensis were studied with regard to Indian conditions, with the immediate objective of utilising the algal biomass at rural levels as animal feed. Thus, simple techniques involving less energy and capital were tested for their suitability. The algal material produced was analyzed for its chemical composition, nutritional quality, supplementary value and toxicological safety. The results obtained demonstrated that Spirulina represents an unobjectionable source of unconventional protein of good quality. Short-term feeding tests with rats did not reveal any negative symptoms which would impair the utilization of Spirulina as food or feed.

  2. Utilization of Spirulina platensis for wastewater treatment in fermented rice noodle factory

    Directory of Open Access Journals (Sweden)

    Sumontip Bunnag

    2010-12-01

    Full Text Available Spirulina platensis is a single-cell blue-green alga which belongs to the family Oscillatoriaceae.S. platensis can grow in polluted water and it has been widely used to remove excess nitrate-nitrogenand total phosphorus content in wastewater from noodle factories. This study was aimed to investigatethe effect of wastewater on growth of S. platensis and to examine its potential to reduce nitrate-nitrogenand total phosphorus contents in wastewater from fermented rice noodle factory. Twenty five percentwastewatermixed Zarrouk’s medium gave rise to the highest growth rate of S. platensis. Optical density(OD of S. platensis culture increased from 0.07±0.04 to 0.24±0.12. Also, the results exhibited the leastvalue of nitrate-nitrogen and total phosphorus contents when performed in 25 % and 100 %wastewater-mixed Zarrouk’s media, respectively.

  3. Biomass Utilization of Spirulina platensis Powder in The Manufacture of Lozenges

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    Jeri Srinur Eka Saputra

    2015-01-01

    Full Text Available Many microalgae of the type S. Platensis are cultivated in Indonesia. Nutrient content owned by S. Platensis microalgae is very good for health, especially the protein content. Innovation diversification of the product is in the form of lozenges. This study aimed to examine the use of S. Platensis biomass powder into lozenges and know the quality of products made from added powder S. Platensis lozenges in physical, chemical, and sensory. The material used in this study were S. Platensis powder obtained from Sukoharjo. The method used in this study was experimental laboratories. The data tested in parametric is analyzed using T-test experimental design with three replications, whereas for non-parametric data is analyzed with Kruskal-Wallis and test continued with Multiple Comparison test. Analyzed data on physical parameters such as hardness and friability; chemicals such as moisture content, protein, and amino acid lysine; sensory (hedonic. The results showed that the formula KI (added S. Platensis powder 20 % significantly (p<0,05 on physical parameters such as hardness and friability; chemicals such as moisture content, protein, and amino acid lysine; sensory (hedonic. Spirulina lozenges formula KI the physical quality of tablets: uniformity of weight (1.001 gram; hardness (4.893 Kp; friability (0.119 %; chemical: water content (2.285 %, protein (24.327 %; highest amino acid profile were L-Aspartic (14.026,3 ppm and lowest amino acid profile was L-Isoleucine (846,37ppm as well as the sensory hedonic with an average value of 7.080.Keyword: Lozenges, quality, Spirulina platensis powder

  4. Utilization of recovered nitrogen from hydrothermal carbonization process by Arthrospira platensis.

    Science.gov (United States)

    Yao, Changhong; Pan, Yanfei; Lu, Hongbin; Wu, Peichun; Meng, Yingying; Cao, Xupeng; Xue, Song

    2016-07-01

    In the context of sustainable cultivation of microalgae, the present study focused on the use of nitrogen from the hot-water extracted biomass residue of Arthrospira platensis by hydrothermal carbonization (HTC) and the sequential cultivation of the same alga with the HTC aqueous phase (AP). Nearly 90% of the nitrogen recovered from HTC into AP was in the organic form. Under nitrogen-limited condition with HTCAP as nitrogen source the yield and content of carbohydrate were enhanced by 21% and 15% respectively compared with that under the same nitrogen level provided by NaNO3, which entitled HTCAP for the substitution of conventional nitrate. In the same way pilot-scale cultivation of A. platensis in raceway ponds outdoors demonstrated that carbohydrate content of 43.8% DW and productivity of 10.3g/m(2)/d was achieved. Notably 54% of organic nitrogen in the HTCAP could be recycled by cultivation of pre-nitrogen starved A. platensis as seeds under nitrogen limitation.

  5. Spirulina platensis

    African Journals Online (AJOL)

    abc

    2013-08-28

    Aug 28, 2013 ... Spirulina platensis is an attractive human food supplement, animals feed and of numerous medicinal uses. The effect ..... Cost and composition of media are challenging factors for viable ..... phycocyanin extraction. Int. J. Zool.

  6. Utilization of rural wastes for algal biomass production with Scenedesmus acutus and Spirulina platensis in India

    Energy Technology Data Exchange (ETDEWEB)

    Venkataraman, L.V.; Devi, K.M.; Mahadevaswamy, M.; Mohammed Kunhi, A.A.

    1982-03-01

    A technology for the production of the green alga, Scenedesmus acutus, and blue-green alga, Spirulina platensis, in clean water has been developed to suit Indian conditions. Experience gained on algal production technology in India indicates the scope for applying this at the rural level for use in the production of animal feed. Spirulina is the most promising alga in view of its amenability to low level technology. Nutrient input to the cultures is one of the most expensive steps. It is shown that agricultural and domestic wastes can be effectively recycled for algal biomass production by replacing, at least partly, the nutrient inputs. Urine and bonemeal reduce the inputs of nitrate, calcium and phosphate salts into the culture medium. Sheep's blood has a growth promoting effect on algal cultures and a good potential for application. Carbon dioxide enriched air-'aerobic biogas'-produced by composting cow dung, can be used as a carbon source for algal cultivation. Several experiments carried out in India indicate the possibility of developing an integrated algal production system in rural areas by means of which wastes can be effectively recycled. The use of algae in poultry and fish feeds is a distinct possibility for the future. (Refs. 25).

  7. Perpendicular magnetic tunnel junction with enhanced anisotropy obtained by utilizing an Ir/Co interface

    Science.gov (United States)

    Yakushiji, Kay; Kubota, Hitoshi; Fukushima, Akio; Yuasa, Shinji

    2016-01-01

    A highly scalable perpendicularly magnetized storage layer of a spin-torque-switching magnetic random-access memory (STT-MRAM) was developed. This storage layer attains a perpendicular magnetic anisotropy (PMA) of above 0.9 erg/cm2 at a thickness of 2 nm. Such high PMA is suitable for pushing STT-MRAM technology beyond the 20 nm node. The key was to realize dual interfacial PMA at both the Ir/Co and FeB/MgO interfaces in the united structure of the storage layer. While a high PMA was retained, a high magnetoresistance ratio (100%) and a low resistance-area product (3.0 Ω µm2) were also achieved.

  8. Effect of germanium dioxide on growth of Spirulina platensis

    Science.gov (United States)

    Cao, Ji-Xiang

    1996-12-01

    This study on the effect of different concentrations of germanium dioxide (GeO2) on the specific growth rate (SGR), pigment contents, protein content and amino acid composition of Spirulina platensis showed that Ge was not the essential element of this alga; that GeO2 could speed up growth and raise protein content of S. platensis, and could possibly influence the photosynthesis system. The concentration range of GeO2 beneficial to growth of S. platensis is from 5 100mg/l. GeO2 is proposed to be utilized to remove contamination by Chlorella spp. usually occurring in the cultivation of Spirulina.

  9. Lead removal by Spirulina platensis biomass.

    Science.gov (United States)

    Al-Homaidan, Ali A; Al-Abbad, Aljawharah F; Al-Hazzani, Amal A; Al-Ghanayem, Abdullah A; Alabdullatif, Jamila A

    2016-01-01

    In this investigation, we report on the biosorption of Pb (II) from aqueous solutions by the nonliving biomass of the micro-alga (cyanobacterium) Spirulina platensis. Propagation of the micro-alga was carried out in outside oblong raceway ponds. The biomass was cleaned, dried and used for the investigation. The effects of pH, adsorbent dose, temperature, initial concentration of Pb (II), and contact time on the adsorption of lead by the dry biomass were studied. The experiments were carried out in 250 ml conical flasks containing 100 ml of test solutions using an orbital incubator at 150 rpm. Concentrations of the metal before and after the experiments were measured using Atomic Absorption Spectrophotometer. Very high levels of Pb (II) removal (>91%) were obtained. The optimum conditions for maximal adsorption by S. platensis were found to be pH 3; 2 g of adsorbent dose; incubation at 26°C; 100 mg/l of lead initial concentration and 60 minutes of contact time. The experimental data fitted well with Freundlich isotherm equation with R(2) values greater than 0.97. Based on our results, we recommend the utilization of S. platensis biomass for heavy metal removal from aqueous solutions.

  10. Perpendicularly magnetized ferrimagnetic [Mn50Ga50/Co2FeAl] superlattice and the utilization in magnetic tunnel junctions

    Directory of Open Access Journals (Sweden)

    Q. L. Ma

    2015-08-01

    Full Text Available The ferrimagnetic superlattice (SL [MnGa/Co2FeAl]n exhibiting perpendicular magnetic anisotropy opened a new method for spintronics materials used in magnetic random access memory, because of the high anisotropy, small damping constant and tunable magnetization. In this work, we fabricated SLs with different MnGa composition and studied the MnGa composition dependence of the structure and magnetic properties of the SLs. Furthermore, we fabricated fully perpendicular magnetic tunnel junctions with SLs as both top and bottom electrodes. A clear tunnel magnetoresistance (TMR effect with TMR ratio of 1.3% at room temperature was observed.

  11. PEMANFAATAN Spirulina platensis SEBAGAI SUPLEMEN PROTEIN SEL TUNGGAL (PST MENCIT (Mus musculus

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    Haryo Kuntoro Adi

    2007-06-01

    Full Text Available The using of Spirulina platensis as Supplement of Single-Celled Protein (SCP to Mice. High protein in Spirulina platensis can be used as a source of Single-Celled Protein. By using mice (Mus musculus as a animal laboratory, the objective of this research is to know the influence of Biomass S. platensis to the increase of body weight of mice. The name of species is Mus musculus, strain is Swiss derivate. Utilized mice were male, 30-50 weighing gram, and 5-7 weeks of age. Treatment group was given by palette and given by biomass of S. Platensis, while control also fed palette but did not give biomass of S. platensis. Yielded biomass was used as food mixed with palette with composition of dry biomass S. platensis with palette was 0%, 10%, 20%, 30%, 40%, and 50%. Data analysis was conducted by using t-tes and analysis of variance. The results showed that by giving of dry biomass of S. platensis affected to the increasement of body weight from the first day until twelfth day of observation, and decrease on the thirteenth and fourteenth day. Pursuant to result of statistic, there is a significant difference (p < 0,05 between before giving and after giving of dry biomass S. platensis during 17 day. By giving dry biomass of S. platensis to mice (Mus musculus at first and second week, it was found the difference of average mice body weight among six concentrations of biomass but did not at the third week. It means that not all concentration of biomass have same effect to the increase of mice body weight as a Single-Celled Protein.

  12. Potential application of microalga Spirulina platensis as a protein source.

    Science.gov (United States)

    Lupatini, Anne Luize; Colla, Luciane Maria; Canan, Cristiane; Colla, Eliane

    2017-02-01

    The high protein level of various microalgal species is one of the main reasons to consider them an unconventional source of this compound. Spirulina platensis stands out for being one of the richest protein sources of microbial origin (460-630 g kg(-1) , dry matter basis), having similar protein levels when compared to meat and soybeans. The use of S. platensis in food can bring benefits to human health owing to its chemical composition, since it has high levels of vitamins, minerals, phenolics, essential fatty acids, amino acids and pigments. Furthermore, the development of new protein sources to supply the shortage of this nutrient is an urgent need, and protein from S. platensis plays an important role in this scenario. In this sense, extraction processes that allow maximum protein yield and total utilization of biomass is an urgent need, and ultrasonic waves have proven to be an effective extraction technique. The number of scientific papers related to protein fraction from S. platensis is still limited; thus further studies on its functional and technological properties are needed. © 2016 Society of Chemical Industry.

  13. Treating urine by Spirulina platensis

    Science.gov (United States)

    Yang, Chenliang; Liu, Hong; Li, Ming; Yu, Chengying; Yu, Gurevich

    In this paper Spirulina platensis with relatively high nutrition was cultivated to treat human urine. Batch culture showed that the consumption of N in human urine could reach to 99%, and the consumption of P was more than 99.9%, and 1.05 g biomass was obtained by treating 12.5 ml synthetic human urine; continuous culture showed that S. platensis could consume N, Cl, K and S in human urine effectively, and the consumption could reach to 99.9%, 75.0%, 83.7% and 96.0%, respectively, and the consumption of P was over 99.9%, which is very important to increase the closure and safety of the bioregenerative life support system (BLSS).

  14. Impact of fishmeal replacement with Arthrospira platensis on growth performance, body composition and digestive enzyme activities of the freshwater prawn, Macrobrachium rosenbergii

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    S. Radhakrishnan

    2016-05-01

    Full Text Available In this study, we assessed the suitable level of replacement of fishmeal with a blue green microalga, Arthrospira platensis in feed for the post larvae (PL of the freshwater prawn, Macrobrachium rosenbergii by evaluating the growth performance, prawn proximate composition, feed utilization parameters and the activity of digestive enzymes. The prawns were fed 5 different diets: a control diet and 4 different diets containing A. platensis at various levels such as 25%, 50%, 75%, 100%. These diets were fed to the PL for 90 days in triplicates. The growth performance in terms of weight gain, specific growth rate and feed efficiency ratio were found significantly (P  25 > 75 > 100% replacement of fishmeal with A. platensis. These results concluded that a partial replacement of the fishmeal with A. platensis at the level of 50% is beneficial for the growth of prawn M. rosenbergii.

  15. Epithermal Neutron Activation Analysis of Spirulina platensis Biomass, of the C-Phycocianin and of DNA Extracted from It

    CERN Document Server

    Mosulishvili, L M; Belokobylsky, A I; Kirkesali, E I; Khizanishvili, A I; Pomyakushina, E V

    2002-01-01

    The epithermal neutron activation analysis (ENAA) was used for study of the biomass of Spirulina platensis. The background levels of concentration 27 macro-, micro- and trace elements ranging from 10^{-3} up to 10^{4} ppm were determined. It was found that the biomass of spirulina does not contain toxic elements above the tolerance levels and can be utilized as a matrix of pharmaceuticals based on it. The concentrations of basic elements in C-phycocianin and DNA extracted from Spirulina platensis were determined by ENAA. A comparison of the element content of a whole spirulina biomass with that of a refined C-phycocianin preparation was made.

  16. Design of high-throughput and low-power true random number generator utilizing perpendicularly magnetized voltage-controlled magnetic tunnel junction

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    Hochul Lee

    2017-05-01

    Full Text Available A true random number generator based on perpendicularly magnetized voltage-controlled magnetic tunnel junction devices (MRNG is presented. Unlike MTJs used in memory applications where a stable bit is needed to store information, in this work, the MTJ is intentionally designed with small perpendicular magnetic anisotropy (PMA. This allows one to take advantage of the thermally activated fluctuations of its free layer as a stochastic noise source. Furthermore, we take advantage of the voltage dependence of anisotropy to temporarily change the MTJ state into an unstable state when a voltage is applied. Since the MTJ has two energetically stable states, the final state is randomly chosen by thermal fluctuation. The voltage controlled magnetic anisotropy (VCMA effect is used to generate the metastable state of the MTJ by lowering its energy barrier. The proposed MRNG achieves a high throughput (32 Gbps by implementing a 64×64 MTJ array into CMOS circuits and executing operations in a parallel manner. Furthermore, the circuit consumes very low energy to generate a random bit (31.5 fJ/bit due to the high energy efficiency of the voltage-controlled MTJ switching.

  17. Design of high-throughput and low-power true random number generator utilizing perpendicularly magnetized voltage-controlled magnetic tunnel junction

    Science.gov (United States)

    Lee, Hochul; Ebrahimi, Farbod; Amiri, Pedram Khalili; Wang, Kang L.

    2017-05-01

    A true random number generator based on perpendicularly magnetized voltage-controlled magnetic tunnel junction devices (MRNG) is presented. Unlike MTJs used in memory applications where a stable bit is needed to store information, in this work, the MTJ is intentionally designed with small perpendicular magnetic anisotropy (PMA). This allows one to take advantage of the thermally activated fluctuations of its free layer as a stochastic noise source. Furthermore, we take advantage of the voltage dependence of anisotropy to temporarily change the MTJ state into an unstable state when a voltage is applied. Since the MTJ has two energetically stable states, the final state is randomly chosen by thermal fluctuation. The voltage controlled magnetic anisotropy (VCMA) effect is used to generate the metastable state of the MTJ by lowering its energy barrier. The proposed MRNG achieves a high throughput (32 Gbps) by implementing a 64 ×64 MTJ array into CMOS circuits and executing operations in a parallel manner. Furthermore, the circuit consumes very low energy to generate a random bit (31.5 fJ/bit) due to the high energy efficiency of the voltage-controlled MTJ switching.

  18. Acute rhabdomyolysis caused by Spirulina (Arthrospira platensis).

    Science.gov (United States)

    Mazokopakis, Elias E; Karefilakis, Christos M; Tsartsalis, Athanasios N; Milkas, Anastasios N; Ganotakis, Emmanuel S

    2008-06-01

    Rhabdomyolysis is a potentially life-threatening disorder that occurs as a primary disease or as a complication of a broad spectrum of other diseases. We report the first case of acute rhabdomyolysis after ingestion of Spirulina (Arthrospira platensis), a plantonic blue-green alga, as a dietary supplement.

  19. High value pigment production from Arthrospira (Spirulina) platensis cultured in seawater.

    Science.gov (United States)

    Leema, J T Mary; Kirubagaran, R; Vinithkumar, N V; Dheenan, P S; Karthikayulu, S

    2010-12-01

    The prospects of utilizing pretreated seawater for the culture of Arthrospira (Spirulina) platensis was evaluated under laboratory conditions with three seawater media and a control: (1) Zarrouk media (freshwater-control) (2) seawater media SW 1 (3) seawater media SW2 and (4) seawater media SW 3. The relative performance of these media were investigated with respect to their biomass production, pigment production (phycocyanin, lutein and betacarotene), and biochemical composition. A. platensis grown in media SW 2 had a biomass production (2.99+/-0.145 g L(-1)) comparable to that of control media (3.114+/-0.085 g L(-1)); highest specific growth rate (0.255 d(-1)) and lowest doubling time (2.720 days). Phycocyanin content of the cells grown in seawater media SW 3(81.85%) was closer to that of control. Similarly the purity ratio of phycocyanin produced from cells grown in seawater media SW 3 and control were closer to 4, while the phycocyanin obtained from cells grown in other two media exhibited lower purity ratios due to accumulation of lower molecular weight carbohydrates. The phycocyanin/Chl-a ratio and the betacarotene/Chl-a ratio of the cells grown in seawater media were higher than control. The lutein content of A. platensis cells grown in seawater media SW 2 was higher than that of control. The cells grown in seawater media had a slightly modified biochemical composition than the control with a higher carbohydrate and lower protein content. All the three seawater based media with fewer chemicals than the control (Zarrouk media) supported the growth of A. platensis as good as the control.

  20. A new restriction endonuclease from Spirulina platensis.

    OpenAIRE

    Kawamura, M; Sakakibara, M; Watanabe, T; Kita, K.; Hiraoka, N; Obayashi, A; Takagi, M; Yano, K

    1986-01-01

    Three restriction endonucleases, Sp1I, Sp1II and Sp1III have been purified partially from Spirulina platensis subspecies siamese and named. Sp1I cleaves bacteriophage lambda DNA at one site, phi X 174 RF DNA at two sites, but does not cleave pBR322 DNA. This enzyme recognizes the sequence 5'CGTACG3' 3'GCATCG5' and cuts the site indicated by the arrows. Sp1II is an isoschizomer of Tth111I and Sp1III is an isoschizomer of HaeIII.

  1. C-phycocyanin extraction from Spirulina platensis wet biomass

    National Research Council Canada - National Science Library

    Moraes, C. C; Sala, Luisa; Cerveira, G. P; Kalil, S. J

    2011-01-01

    C-Phycocyanin is a natural blue dye used in food and pharmaceutical industry. In the present study, a simple and efficient method to extract C-phycocyanin from Spirulina platensis wet biomass is reported...

  2. Effect of Spirulina platensis powder on metabolic syndrome in ...

    African Journals Online (AJOL)

    The syndrome was induced by high fructose and fat diet in Sprague Dawley rat. ... the first group (high-fructose diet control) received distilled water, the second ... Keywords: Spirulina platensis, metabolic syndrome, fructose, diabetes, fat diet.

  3. Production of Spirulina platensis by adding sodium bicarbonate and ...

    African Journals Online (AJOL)

    SAM

    2014-04-02

    Apr 2, 2014 ... In this study, dry chicken manure (DCM) was used as the source of nitrogen in ... Key words: Spirulina platensis, dry chicken manure, sodium bicarbonate, urea. ..... School of Pharmacy and Biomedical Science and School of.

  4. PENGARUH WAKTU PANEN DAN NUTRISI MEDIA TERHADAP BIOPIGMEN Spirulina platensis

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    Iriani - setyaningsih

    2014-06-01

    Full Text Available Spirulina platensis merupakan alga hijau biru yang mengandung biopigmen fi kosianin dan antioksidanyang bermanfaat bagi kesehatan. Produksi biopigmen dipengaruhi oleh nutrien dan umur kultur. Penelitianini bertujuan menentukan pengaruh media dan umur panen terhadap kandungan fi kosianin dan aktivitasantioksidan. Kultivasi S. platensis dilakukan di dalam laboratorium menggunakan media KT, MT, dan Walne.Ekstraksi fi kosianin dilakukan menggunakan pelarut akuades dan bufer fosfat. Kandungan fi kosianin S.platensis dalam media MT (10,07 mg/mL tidak berbeda nyata dengan media Walne (7,49 mg/mL, tetapiberbeda nyata dengan media KT (0,71 mg/mL. Aktivitas antioksidan S. platensis pada ketiga media tidakberbeda nyata. Kandungan fi kosianin S. platensis pada hari ke-12 (10,42 mg/mL berbeda nyata dengan harike-6 (2,70 mg/mL, hari ke-14 (8,14 mg/mL, dan hari ke-17 (3,09 mg/mL. Aktivitas antioksidan S. platensispada keempat umur panen tidak berbeda nyata.Kata kunci: antioksidan, fi kosianin, Spirulina platensis, waktu panen

  5. PENGARUH WAKTU PANEN DAN NUTRISI MEDIA TERHADAP BIOPIGMEN Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Iriani - setyaningsih

    2015-07-01

    Full Text Available Spirulina platensis merupakan alga hijau biru yang mengandung biopigmen fi kosianin dan antioksidanyang bermanfaat bagi kesehatan. Produksi biopigmen dipengaruhi oleh nutrien dan umur kultur. Penelitianini bertujuan menentukan pengaruh media dan umur panen terhadap kandungan fi kosianin dan aktivitasantioksidan. Kultivasi S. platensis dilakukan di dalam laboratorium menggunakan media KT, MT, dan Walne.Ekstraksi fi kosianin dilakukan menggunakan pelarut akuades dan bufer fosfat. Kandungan fi kosianin S.platensis dalam media MT (10,07 mg/mL tidak berbeda nyata dengan media Walne (7,49 mg/mL, tetapiberbeda nyata dengan media KT (0,71 mg/mL. Aktivitas antioksidan S. platensis pada ketiga media tidakberbeda nyata. Kandungan fi kosianin S. platensis pada hari ke-12 (10,42 mg/mL berbeda nyata dengan harike-6 (2,70 mg/mL, hari ke-14 (8,14 mg/mL, dan hari ke-17 (3,09 mg/mL. Aktivitas antioksidan S. platensispada keempat umur panen tidak berbeda nyata.Kata kunci: antioksidan, fi kosianin, Spirulina platensis, waktu panen

  6. Effect of microalga Spirulina platensis (Arthrospira platensis on hippocampus lipoperoxidation and lipid profile in rats with induced hypercholesterolemia

    Directory of Open Access Journals (Sweden)

    Telma Elita Bertolin

    2009-10-01

    Full Text Available Studies have been conducted on microalga Spirulina platensis (Arthrospira platensis due to its therapeutic potential in several areas, including the capacity for preventing and decreasing the damages caused by hyperlipidemia and the antioxidant activity. The aim of the study was to evaluate the effect of microalga Spirulina platensis on hippocampus lipoperoxidation and lipid profile in rats with induced hypercholesterolemia during 60 days. The measurement of hippocampus lipoperoxidation did not demonstrate significant difference (p>0.05 when Spirulina platensis was added to hypercholesterolemic diet. The evaluation of lipid profile showed that the administration of the microalga in therapeutic and preventive ways led to a significant protective effect (pA microalga Spirulina platensis (Arthrospira platensis vem sendo fonte de pesquisas devido a evidências de seu potencial terapêutico em diversas áreas, dentre elas a capacidade de prevenção e diminuição dos danos causados por dislipidemias e sua atividade antioxidante. Objetivou-se avaliar o efeito da microalga Spirulina platensis sobre a lipoperoxidação no hipocampo e perfil lipídico sérico em ratos com hipercolesterolemia induzida durante 60 dias. A dosagem da lipoperoxidação no hipocampo não demonstrou diferença significativa (p>0,05 quando Spirulina platensis foi adicionada na dieta hipercolêsterolemica. A avaliação do perfil lipídico demonstrou que a administração da microlaga de forma terapêutica e preventiva demonstrou efeito significativo (p<0,05 na proteção do desenvolvimento de hipercolesterolemia.

  7. UTILIZAÇÃO DE Spirulina platensis COMO SUPLEMENTO ALIMENTAR DURANTE A REVERSÃO SEXUAL DE TILÁPIA DO NILO

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    RICARDO LAFAIETE MOREIRA

    2010-01-01

    Full Text Available This study aimed to evaluate the influence of S. platensis as a food supplement for Nile tilapia post-larvae. Two trials was running. In the first, was used two treatments, one offered freshwater microalgae (green water and other offered microalga S. platensis. In the second trial, were evaluated the effect of without copepods, administration of copepods alone and copepods enriched with S. platensis. Throughout the study, all animals were fed diets with masculinizing hormone 17-K-methyl-testosterone. It was evaluated the growth in weight and length, the survival rate and the rate of sex reversal of tilapia (mean +,- SD. In the first trial, the fish that received the S. platensis and receiving freshwater microalgae showed as result, 0.21 +,- 0.042 g; 2.50 +,- 0.091 cm; 97.5 ± 1,00% and 0.11 +,- 0.022 g; 1.91 +,- 0.419 cm; 98.33 +,- 0.70%, respectively. In the second trial, when the copepods were utilized, with and without S. platensis, the post-larvae as result, 0.221 ± 0.008 g; 2.70 ± 0.070 cm; 86.67 +,- 1.03% and 0.211 +,- 0.014 g; 2.56 ± 0.121 cm; 77.50 +,- 1.33%, respectively. The animals that received only commercial had as result, 0.190 +,- 0.008 g; 2.22 +,- 0.215 cm and 79.17 +,-0.21%. Using S. platensis resulted in better growth in weight and length, but did not affect survival and rates of sex reversal Nile tilapia post-larvae of exposed to natural food.

  8. Medical Application of Spirulina platensis Derived C-Phycocyanin

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    Qian Liu

    2016-01-01

    Full Text Available Along with the development of marine biological pharmaceutical research, high-effective and low-toxic drugs and functional foods isolated from marine organisms have become a new field of pharmacy and bromatology. The pharmacological actions, such as anti-inflammation, antioxidation, antitumor, immunological enhancement, and hepatorenal protection of C-phycocyanin (C-PC from Spirulina platensis, have been reported, and C-PC has important value of development and utilization either as drug or as functional food. There are many researches about the various pharmacological actions and mechanisms of C-PC, but related reports are only to some extent integrated deeply and accurately enough, which put some limitations to the further application of C-PC in medicine. Particularly, with the improvement of living standards and attention to health issues, C-PC being a functional food is preferred by more and more people. C-PC is easy to get, safe, and nontoxic; thus, it has a great potential of research and development as a drug or functional food. Here, the separation and purification, physicochemical properties, physiological and pharmacological activities, safety, and some applications are reviewed to provide relevant basis for the development of natural medicine and applied products.

  9. Spirulina platensis: process optimization to obtain biomass

    Directory of Open Access Journals (Sweden)

    Iracema de Oliveira Moraes

    2013-02-01

    Full Text Available Spirulina platensis is a photoautotrophic mesophilic cyanobacterium. Its main sources of nutrients are nitrate, urea, and ammonium salts. Spirulina cultivation requires temperature, light intensity, and nutrient content control. This microalgae has been studied and used commercially due to its therapeutic and antioxidant potential. In addition, several studies have reported its ability to use CO2, its immune activity, and use as an adjuvant nutritive factor in the treatment of obesity. The objective of this study is the production of biomass of S. platensis using different rates of stirring, nitrogen source, amount of micronutrients, and luminosity. A 2(4 experimental design with the following factors: stirring (120 and 140 RPM, amount of nitrogen (1.5 and 2.5 g/L, amount of micronutrients (0,25 and 0,75 mL/L (11 and 15 W, and luminosity was used. Fermentation was performed in a 500 mL conical flask with 250 mL of culture medium and 10% inoculum in an incubator with controlled stirring and luminosity. Fermentation was monitored using a spectrophotometer (560 nm, and each fermentation lasted 15 days. Of the parameters studied, luminosity is the one with the highest significance, followed by the amount of nitrogen and the interaction between stirring and micronutrients. Maximum production of biomass for 15 days was 2.70 g/L under the following conditions: luminosity15W; stirring, 120 RPM; source of nitrogen, 1.5 g/L; and micronutrients, 0.75 mL/L.

  10. Dietary effects of Spirulina platensis on hematological and serum biochemical parameters of rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Yeganeh, Sakineh; Teimouri, Mahdi; Amirkolaie, Abdolsamad Keramat

    2015-08-01

    This study evaluated the effects of diets containing 0, 2.5, 5, 7.5 and 10% of Spirulina platensis on hematological and serum biochemical parameters of rainbow trout (Oncorhynchus mykiss). Fish (n=180; 101±8 g) were randomly divided into fifteen 300 L fiberglass tanks in triplicates for a period of ten weeks. The RBC, WBC, hemoglobin, total protein and albumin levels increased significantly in the groups supplemented with S. platensis. Dietary inclusion of S. platensis had no significant effects on hematocrit, cholesterol, triglyceride and lactate of the blood. HDL-cholesterol was larger in rainbow trout fed 10% S. platensis in comparison with the other diets, whereas LDL-cholesterol significantly decreased with increasing of S. platensis inclusion. Cortisol and glucose significantly decreased with increasing of S. platensis inclusion. The present results demonstrate that inclusion of 10% S. platensis can be introduced as an immunostimulant in rainbow trout diets.

  11. Antioxidant activity of different fractions of Spirulina platensis protean extract.

    Science.gov (United States)

    Piñero Estrada, J E; Bermejo Bescós, P; Villar del Fresno, A M

    2001-01-01

    Spirulina platensis, planktonic blue-green algae, is gaining increasing attention because of its nutritional and medicinal properties. This microalgae contains phycobiliproteins (phycocyanin and allophycocyanin). Previous reports from our laboratory have shown that a protean extract of S. platensis is a potent free-radical scavenger (hydroxyl and peroxyl radicals) and inhibits microsomal lipid peroxidation. The aim of this study was to purify and characterize phycocyanin of S. platensis. Besides, we tried to demonstrate that one of the main components responsible for this antioxidant activity is a biliprotein phycocyanin. For this purpose, we studied the antioxidant activity of different fractions obtained during the phycocyanin purification process, through the scavenger activity of hydroxyl radical. We also observed that an increase in phycocyanin content was related to an increase in the antioxidant activity in different fractions, and therefore phycobiliprotein phycocyanin is the component mainly responsible for the antioxidant activity.

  12. Binding characteristics of copper and cadmium by cyanobacterium Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Fang Linchuan [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Zhou Chen; Cai Peng [Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Chen Wenli [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Rong Xingmin; Dai Ke; Liang Wei [Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Gu Jidong [Department of Ecology and Biodiversity, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong); Huang Qiaoyun, E-mail: qyhuang@mail.hzau.edu.cn [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China)

    2011-06-15

    Highlights: {yields} The carboxyl groups play a vital role in the binding of Cu(II) and Cd(II) to S. platensis cells. {yields} Ion exchange and complexation are the dominating mechanism for Cu(II) and Cd(II) adsorption. {yields} XAFS analysis provided evidence for the inner-sphere complexation of Cu by carboxyl ligands and showed that Cu is complexed by two 5-membered chelate rings on S. platensis surface. - Abstract: Cyanobacteria are promising biosorbent for heavy metals in bioremediation. Although sequestration of metals by cyanobacteria is known, the actual mechanisms and ligands involved are not very well understood. The binding characteristics of Cu(II) and Cd(II) by the cyanobacterium Spirulina platensis were investigated using a combination of chemical modifications, batch adsorption experiments, Fourier transform infrared (FTIR) spectroscopy and X-ray absorption fine structure (XAFS) spectroscopy. A significant increase in Cu(II) and Cd(II) binding was observed in the range of pH 3.5-5.0. Dramatical decrease in adsorption of Cu(II) and Cd(II) was observed after methanol esterification of the nonliving cells demonstrating that carboxyl functional groups play an important role in the binding of metals by S. platensis. The desorption rate of Cu(II) and Cd(II) from S. platensis surface was 72.7-80.7% and 53.7-58.0% by EDTA and NH{sub 4}NO{sub 3}, respectively, indicating that ion exchange and complexation are the dominating mechanisms for Cu(II) and Cd(II) adsorption. XAFS analysis provided further evidence on the inner-sphere complexation of Cu by carboxyl ligands and showed that Cu is complexed by two 5-membered chelate rings on S. platensis surface.

  13. Moisture sorption characteristics of microalgae Spirulina platensis

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    E. G. Oliveira

    2009-03-01

    Full Text Available In recent times, the microalgae Spirulina platensis has been used as a functional ingredient in several food applications; its process involving drying and storage steps. Moisture equilibrium data for adsorption isotherms of microalgae Spirulina were investigated at 10, 20 and 30ºC and for desorption, at 40, 50 and 60ºC, using the gravimetric static method. The experimental data were analyzed by GAB and BET models. The GAB equation showed the best fitting to the experimental data with R² ≈ 99% and MRE < 10%. The water surface area values calculated by GAB and BET models were very similar. The isosteric heats were determined by application of Clausius-Clapeyron equation to sorption isotherms obtained from the best-fitting equation. The isosteric heat and the entropy of desorption isotherm presented similar behavior, with a sharp change in an equilibrium moisture content of 10%. The enthalpy-entropy compensation theory was applied to the isotherms, indicating that they are enthalpy-controlled.

  14. Attached cultivation for improving the biomass productivity of Spirulina platensis.

    Science.gov (United States)

    Zhang, Lanlan; Chen, Lin; Wang, Junfeng; Chen, Yu; Gao, Xin; Zhang, Zhaohui; Liu, Tianzhong

    2015-04-01

    To improve cultivation efficiency for microalgae Spirulina platensis is related to increase its potential use as food source and as an effective alternative for CO2 fixation. The present work attempted to establish a technique, namely attached cultivation, for S. platensis. Laboratory experiments were made firstly to investigate optimal conditions on attached cultivation. The optimal conditions were found: 25 g m(-2) for initial inoculum density using electrostatic flocking cloth as substrata, light intensity lower than 200 μmol m(-2) s(-1), CO2 enriched air flow (0.5%) at a superficial aeration rate of 0.0056 m s(-1) in a NaHCO3-free Zarrouk medium. An outdoor attached cultivation bench-scale bioreactor was built and a 10d culture of S. platensis was carried out with daily harvesting. A high footprint areal biomass productivity of 60 g m(-2) d(-1) was obtained. The nutrition of S. platensis with attached cultivation is identical to that with conventional liquid cultivation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Antioxidant potential of selected Spirulina platensis preparations.

    Science.gov (United States)

    Dartsch, Peter C

    2008-05-01

    Recent studies suggest that Spirulina, a unicellular blue-green alga, may have a variety of health benefits and therapeutic properties and is also capable of acting as an antioxidant and antiinflammatory agent. In this study, a cell-free and a cell-based test assay were used to examine the antioxidant and antiinflammatory properties of four selected Spirulina platensis preparations: (1) Biospirulina, (2) SpiruComplex, a preparation with naturally bound selenium, chromium and zinc, (3) SpiruZink, a preparation with naturally bound zinc, (4) Zinkspirulina + Acerola, a preparation with naturally bound zinc and acerola powder. The cell-free test assay used potassium superoxide as a donor for superoxide radicals, whereas the cell-based test assay used the formation of intracellular superoxide radicals of functional neutrophils upon stimulation by phorbol-12-myristate-13-acetate as a model to investigate the potential of Spirulina preparations to inactivate superoxide radicals. In accordance with the recommended daily dosage, test concentrations ranging from 50 to 1000 microg/mL were chosen. The results showed a dose-dependent inactivation of free superoxide radicals (antioxidant effect) as well as an antiinflammatory effect characterized by a dose-dependent reduction of the metabolic activity of functional neutrophils and a dose-dependent inactivation of superoxide radicals generated during an oxidative burst. The results demonstrate that the tested Spirulina preparations have a high antioxidant and antiinflammatory potential. Especially SpiruZink and Zinkspirulina + Acerola might be useful as a supportive therapeutic approach for reducing oxidative stress and/or the generation of oxygen radicals in the course of inflammatory processes.

  16. CROMOSOMAS EN VERNONIA PLATENSIS Y ESPECIES AFINES (ASTERACEAE

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    Massimiliano Dematteis

    2010-11-01

    Full Text Available Fueron analizados los cromosomas somáticos de Vernonia platensis y otras tres especies estrechamente relacionadas. Todas éstas especies pertenecen a la subsección o serie Flexuosae, que es el único grupo americano con el número básico de cromosomas x = 10. En el presente trabajo se analizan los cromosomas somáticos de cuatro especies del grupo Flexuosae; se dan a conocer dos nuevos citotipos para V. platensis y se presentan por primera vez los cariotipos de V. verbascifolia y V. platensis. Los resultados del análisis de los cromosomas son los siguientes: V.flexuosa, 2n = 40 (28m + 12sm; V.lepidifera, 2n = 20 (8m + 2m-sm + 10sm, V. platensis, 2n = 20 (10m + 2m-sm + 8sm, 2n=40, 2n=60, 2n=80 y V.verbascifolia, 2n=20 (8m + 4m-sm + 8sm. El citotipo 4x, 6x y 8x de V.platensis presenta el mismo cariotipo diploide lo que sugiere un origen autopoliploide.  Los cariotipos de las especies aquí reportadas difieren principalmente en longitud total, asimetría y número de metacéntricos y submetacéntricos. Muestran también variación en el número, forma y ubicación de los satélites. Los resultados se discuten en relación a la posición taxonómica de las especies y los estudios cromosómicos previos en el grupo.

  17. Investigation and modeling of biomass decay rate in the dark and its potential influence on net productivity of solar photobioreactors for microalga Chlamydomonas reinhardtii and cyanobacterium Arthrospira platensis.

    Science.gov (United States)

    Le Borgne, François; Pruvost, Jérémy

    2013-06-01

    Biomass decay rate (BDR) in the dark was investigated for Chlamydomonas reinhardtii (microalga) and Arthrospira platensis (cyanobacterium). A specific setup based on a torus photobioreactor with online gas analysis was validated, enabling us to follow the time course of the specific BDR using oxygen monitoring and mass balance. Various operating parameters that could limit respiration rates, such as culture temperature and oxygen deprivation, were then investigated. C. reinhardtii was found to present a higher BDR in the dark than A. platensis, illustrating here the difference between eukaryotic and prokaryotic cells. In both cases, temperature proved an influential parameter, and the Arrhenius law was found to efficiently relate specific BDR to culture temperature. The utility of decreasing temperature at night to increase biomass productivity in a solar photobioreactor is also illustrated.

  18. Development of cassava doughnuts enriched with Spirulina platensis biomass Desenvolvimento de 'sonho de mandioca' enriquecido com biomassa de Spirulina platensis

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    Samantha Ferreira Rabelo

    2013-03-01

    Full Text Available The cyanobacteria Spirulina platensis has been cultivated in a fed batch process with urea as the nitrogen source, in order to obtain dehydrated biomass for incorporation into food, aiming at nutritional enrichment and the production of a functional character, due to the amount of proteins, vitamins and several bioactive compounds found in this cyanobacterium. In this study, response surface methodology was used to analyze the substitution of wheat flour by cassava in the development of doughnuts with added Spirulina platensis biomass and inverted sugar, in order to increase the rate of the Maillard's reaction and mask the green colour of the biomass. The formulations were evaluated in relation to their proximate, sensory and technological compositions, which, when compared to the standard formulation, without the addition of S. platensis biomass and inverted sugar, showed the feasibility of adding the biomass to bestow nutritional enrichment without significantly affecting the sensory acceptance of the product or its typical characteristics.Cultivos da cianobactéria Spirulina platensis vêm sendo conduzidos utilizando-se ureia como fonte de nitrogênio, em processo descontínuo alimentado, para obtenção de biomassa desidratada para ser incorporada em alimentos visando enriquecimento nutricional e conferir caráter funcional em virtude da composição rica em proteínas, vitaminas e diversos componentes bioativos. Neste trabalho, foi estudada a substituição da farinha de trigo pela mandioca, além da adição de biomassa de Spirulina platensis e açúcar invertido, para desenvolver um 'sonho' com elevada taxa da Reação de Maillard para mascarar a coloração verde da biomassa, por meio da metodologia de superfície de resposta. As formulações foram avaliadas em relação aos aspectos de composição centesimal, sensoriais e tecnológicos que, quando comparados com o padrão, sem adição de biomassa de S. platensis e açúcar invertido

  19. Fresh pasta production enriched with Spirulina platensis biomass

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    Ailton Cesar Lemes

    2012-10-01

    Full Text Available The aim of this work was to study the enrichment of Spirulina platensis in wheat flour to prepare fresh pasta to evaluate the green color and nutritional enrichment in addition to functional properties due to the presence of the bioactive compounds in the cyanobacterium. The pastas were evaluated for the centesimal composition, microbiological contamination, sensorial acceptance and technological characteristics such as cooking time, water absorption, volume displacement and loss of solids. The superior protein contents and the satisfactory technological and sensorial attributes compared with the control with no cyanobacterium showed the usefulness of incorporating S. platensis biomass in the fresh pastas. The microbiological quality was in compliance with the legislation in force. The sensorial quality was considered satisfactory (“liked very much” and purchase intention high (“probably would buy”.

  20. Extraction and In Vitro Antimalarial Activity Phycocyanin from Spirulina platensis

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    Diah Anggraini

    2016-04-01

    Full Text Available Phycocyanin is biopigment found only in a conductor such as Spirulina platensis. Phycocyanin from Nostoc can inhibit Plasmodium falciparum with IC50 8.4 μg/mL so that phycocyanin from S. platensis also can inhibit P. falciparum like Nostoc. The aim of this study was to determine the best method for phycocyanin extraction using three solvents. They were phosphate buffer, water, and aseton. Spirulina were cultured in the conditions intensity of light 3000 Lux, salinity 15 ppt, dark-light 8-16 hours. The response parameters of this study were C-phycocyanin (C-PC content, yield, and protein content. Yield biomass of Spirulina which cultivated using toplest was higher than the aquarium. The best solvent for phycocyanin extraction was a phosphate buffer with C-PC content, yield, and protein content 8 mg/mL, 202.26 mg/g, and 1.88%.

  1. Isolation, characterization and localization of extracellular polymeric substances from the cyanobacterium Arthrospira platensis strain MMG-9

    NARCIS (Netherlands)

    Ahmed, M.; Moerdijk-Poortvliet, T.C.W.; Wijnholds, A.; Stal, L.J.; Hasnain, S.

    2014-01-01

    Arthrospira platensis is a cyanobacterium known for its nutritional value and secondary metabolites. Extracellular polymeric substances (EPS) are an important trait of most cyanobacteria, including A. platensis. Here, we extracted and analysed different fractions of EPS from a locally isolated strai

  2. Effect of mass concentration of immobilized Spirulina platensis on nitrogen removal from simulated shrimp pond water

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    Patama Lerksasen

    2007-11-01

    Full Text Available Spirulina platensis strain BP immobilized on fibrous polyester mat was applied for nitrogen removal from simulated shrimp pond water. Different S. platensis mass on mat was built up during immobilizing process by varying the amount of batch fed suspended S. platensis cells. During immobilization, 0.2 OD560 S. platensis was replenished to reactor and chlorophyll-a in the solution was monitored. The immobilized S. platensis mass was 63, 49 and 19 g dw-S. platensis/m2 for Sp V-1, Sp IV-1 and Sp II-1 mat reactors adding five, four and two times of 0.2 OD560 S. platensis respectively. In accordance with statistic, the results of nitrogen removal tests by applying those immobilized mats in circulated batch system reactors loaded with 1.94 gN/m2-d showed that there were significant differences on ammonia removal among the different initial S. platensis mass on mats (ANOVA; P<0.05. The Sp V-1, Sp IV-1 and Sp II-1 mats could reduce the ammonia nitrogen concentration from 1 mg-N/L to the level as low as 0.18 mg-N/L within 2 weeks. Transformation of 75-81% ammonia nitrogen to organic nitrogen in microalgal cells, of which 27-43% were detached to solution, resulted to 44-58% total nitrogen removed from the system.

  3. Growth promotion effect of steelmaking slag on Spirulina platensis

    Science.gov (United States)

    Nogami, R.; Tam, L. T.; Anh, H. T. L.; Quynh, H. T. H.; Thom, L. T.; Nhat, P. V.; Thu, N. T. H.; Hong, D. D.; Wakisaka, M.

    2016-04-01

    A growth promotion effect of steelmaking slag on Spirulina platensis M135 was investigated. The growth promotion effect was obtained that was 1.27 times greater than that obtained by the control by adding 500 mg L-1 of steelmaking slag and culturing for 60 days. The lipid content decreased in a concentration-dependent manner with steelmaking slag, whereas the carbohydrate content remained constant. The protein content of S. platensis M135 increased in a concentration-dependent manner with steelmaking slag when cultured at day 45. The superoxide dismutase activity of S. platensis M135 exhibited a decreasing trend in a time-dependent manner and an increasing trend in the control. The superoxide dismutase activity was lower than that of the control at day 1 but was higher at day 30. No genetic damage was observed up to 500 mg L-1 of steelmaking slag at 30 days of culture. Recovery from genetic damage was observed at 1,000 mg L-1 of steelmaking slag but not at higher concentrations.

  4. Separation and nanoencapsulation of antitumor polypeptide from Spirulina platensis.

    Science.gov (United States)

    Zhang, Bochao; Zhang, Xuewu

    2013-01-01

    Spirulina platensis is a multicellular edible blue-green alga with abundant proteins (∼ 60%). No report is available on the antitumor polypeptides from the whole proteins of S. platensis. In this study, for the first time, an antitumor polypeptide Y2 from trypsin digest of S. platensis proteins was obtained by using freeze-thawing plus ultrasonication extraction, hydrolysis with four enzymes (trypsin, alcalase, papain, and pepsin), and gel filtration chromatography. The results showed that the degree of hydrolysis can be ordered as: trypsin (38.5%) > alcalase (31.2%) > papain (27.8%) > pepsin (7.1%). For MCF-7 and HepG2 cells, at 250 µg/mL, the maximum inhibitory rate of Y2 was 97%, while standard drug 5-FU was 55 and 97%, respectively. Furthermore, the nanoencapsulation of Y2 with chitosan (CS) was also investigated. After nanoencapsulation, the maximum encapsulation efficiency and polypeptides contents are 49 and 15%, respectively; and the antitumor activity is basically not lost. These data demonstrated the potential of nanopolypeptides (Y2-CS) in food and pharmaceutical applications.

  5. Comparison of the therapeutic effects of extracts from Spirulina platensis and amnion membrane on inflammation-associated corneal neovascularization

    Science.gov (United States)

    Yang, Ling-Ling; Zhou, Qing-Jun; Wang, Yao; Gao, Yan; Wang, Yi-Qiang

    2012-01-01

    AIM To compare the therapeutic effects of polysaccharide extract from Spirulina platensis (PSP) and extract from amnion membrane (AME) on alkali burn-induced corneal neovascularization (CorNV). METHODS PSP and AME were extracted from dry powder of Spirulina platensis and human aminion membrane respectively. Murine CorNV was induced by applying 1N sodiumhydroxide (NaOH) solution directly on the mice corneas. PSP and AME extracts were administered topically on the corneas 4 times daily for 7 days. The therapy effects of PSP and AME extracts were evaluated daily using slit-lamp. At the end of the therapy, corneas were harvested for H&E staining, masson trichrome staining, immunohistochemical study, and semi-quantification reverse transcriptive PCR (RT-PCR) was utilized for measurement of inflammation-related molecules. RESULTS Topical application of PSP extract had significant therapeutic effects on CorNV that could be shown in various assays of the corneas. Compared with AME extract, PSP extract treatment was more effective in suppressing CorNV in terms of vessel length and levels of cluster of differentiation 31 (CD31) proteins or the angiogenesis related genes like vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9). PSP also inhibited inflammation more markedly by more effectively inhibiting mononuclear and polymorphonuclear cells infiltration into the corneal stroma and reducing levels of stromal cell-derived factor-1 (SDF1), tumor necrosis factor-alpha (TNFα) and macrophage inflammatory protein-3 (MIP3a). In additon, corneas of PSP group had a more regular and compact architecture of collagen with thinner corneal thickness than in the AME group. CONCLUSION Polysaccharide extract from Spirulina platensis inhibited alkali burn-induced inflammation and CorNV more effectively than AME extract at the studied doses, thus may be used for the therapy of corneal diseases involving neovascularization and

  6. Effects of dissolved organic matter on the growth and pigments synthesis of Spirulina platensis ( Arthrospira )

    Institute of Scientific and Technical Information of China (English)

    MA Zengling; GAO Kunshan; WATANABE Teruo

    2006-01-01

    Excessive accumulation of dissolved organic matter (DOM) in the culture ponds of Spirulina platensis is usually considered to be one of the potential factors affecting the production of S. platensis, however, we are not quite aware of effects of DOM on the growth and pigments synthesis of S. platensis. In the present study, S. platensis was grown in batch or semi-continuous cultures using the filtrate in the culture ponds that had not been renewed for years. It was found that disssolved organic carbon up to 60 mg/L did not bring about an inhibitory effect on the growth of S. platensis, but increased the contents of chlorophyll a and phycocyanin instead. However, further accumulation of dissolved organic matter could decrease the content of chlorophyll a.

  7. DESEMPENHO DE CORDEIROS SANTA INÊS SUBMETIDOS A ALEITAMENTO ARTIFICIAL ENRIQUECIDO COM Spirulina platensis

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    Leilson Rocha Bezerr a

    2010-06-01

    Full Text Available The experiment was carried out in Maria Paz Ranch/SheepProduction Department, in São José de Espinharas, PB. Analyseswere performed in the Laboratory of Animal Nutrition/Centrode Saúde e Tecnologia Rural/Universidade Federal de CampinaGrande. The objectives of this study were to evaluate the effectof the supplementation with cow milk enriched with Spirulinaplatensis (Sp on lamb performance submitted to creep feeding,and determine the most adequate period to suplemet nursinglambs with Spirulina platensis. Data on dry matter (DMC andcrude protein (CPC consumptions, body weight (BW, and meandaily body weight gain (MDBWG were colleted. The three levelsof Spirulina supplementation were assigned to 30 lambs (plotsaccording to a randomized block (lamb weight design with 10replications. Data were collected in four consecutive periods,characterizing a split plot in time. DM and CP consumptions werenot affected by spirulina level x period interaction, and increasedwith periods (animal age. BW and MDBWG were affected bythe spirulina level x period interaction. Spirulina levels affectedMDBWG only from day 0 to day 15, when the MDBWG (300gwas higher at level 10g than at level zero of Spirulina that resulted in 205g in MDBWG. Live body weight at the end of each periodwas also higher when the lambs were supplemented with 10 g ofSpirulina (12.00 17.02, 19.71 and 25.30kg, respectively, for thefour consecutive periods. The dilution of Spirulina platensis incow milk showed to be efficient on the daily performance of lambswhen utilized in concentration of 10g/day and from period 15 to30 days of age.

  8. Spirulina platensis and phycocyanobilin activate atheroprotective heme oxygenase-1: a possible implication for atherogenesis.

    Science.gov (United States)

    Strasky, Zbynek; Zemankova, Lenka; Nemeckova, Ivana; Rathouska, Jana; Wong, Ronald J; Muchova, Lucie; Subhanova, Iva; Vanikova, Jana; Vanova, Katerina; Vitek, Libor; Nachtigal, Petr

    2013-11-01

    Spirulina platensis, a water blue-green alga, has been associated with potent biological effects, which might have important relevance in atheroprotection. We investigated whether S. platensis or phycocyanobilin (PCB), its tetrapyrrolic chromophore, can activate atheroprotective heme oxygenase-1 (Hmox1), a key enzyme in the heme catabolic pathway responsible for generation of a potent antioxidant bilirubin, in endothelial cells and in a mouse model of atherosclerosis. In vitro experiments were performed on EA.hy926 endothelial cells exposed to extracts of S. platensis or PCB. In vivo studies were performed on ApoE-deficient mice fed a cholesterol diet and S. platensis. The effect of these treatments on Hmox1, as well as other markers of oxidative stress and endothelial dysfunction, was then investigated. Both S. platensis and PCB markedly upregulated Hmox1 in vitro, and a substantial overexpression of Hmox1 was found in aortic atherosclerotic lesions of ApoE-deficient mice fed S. platensis. In addition, S. platensis treatment led to a significant increase in Hmox1 promoter activity in the spleens of Hmox-luc transgenic mice. Furthermore, both S. platensis and PCB were able to modulate important markers of oxidative stress and endothelial dysfunction, such as eNOS, p22 NADPH oxidase subunit, and/or VCAM-1. Both S. platensis and PCB activate atheroprotective HMOX1 in endothelial cells and S. platensis increased the expression of Hmox1 in aortic atherosclerotic lesions in ApoE-deficient mice, and also in Hmox-luc transgenic mice beyond the lipid lowering effect. Therefore, activation of HMOX1 and the heme catabolic pathway may represent an important mechanism of this food supplement for the reduction of atherosclerotic disease.

  9. Nuevas evidencias acerca de la presencia de Stegomastodon platensisStegomastodon platensis Ameghino, 1888, Proboscidea: Gomphotheriidae, en el Pleistoceno tardío de Chile central

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    Labarca, R.

    2016-06-01

    Full Text Available This paper contextualizes, describes and taxonomically assigned cranial and dental Gomphotheriidae materials from the El Trebal 1, late Pleistocene form central Chile. Starting from metric and morphological variables fossils are included in Stegomastodon platensisStegomastodon platensis. Taxonomic implications of this finding as well as some regional paleoenvironmental history are discussed.El presente trabajo contextualiza, describe, y asigna taxonómicamente los materiales craneales y dentales de Gomphotheriidae provenientes del sitio El Trebal 1, Pleistoceno tardío de Chile central. A partir de variables métricas y morfológicas los fósiles son incluidos en Stegomastodon platensisStegomastodon platensis. Se discuten las implicancias taxonómicas de este hallazgo así como algunos antecedentes paleoambientales regionales.

  10. Electrical-Discharge Machining Of Perpendicular Passages

    Science.gov (United States)

    Malinzak, R. Michael; Booth, Gary N.

    1996-01-01

    Perpendicular telescoping electrode used to perform electrical-discharge machining (EDM) of internal passage through previously inaccessible depth of metal workpiece. More specifically, used to make internal passage perpendicular to passage entering from outer surface.

  11. Drive integration challenges for perpendicular recording

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, S.E.; Lairson, B.M.; Nguy, Hai; Nguyen, Linda; Huang, Ton; Adler, Jason; Gopalaswamy, Srini

    2001-10-01

    Integration of heads and media for perpendicular recording into disk drives will require new developments in several areas. This paper discusses the methods we use to characterize error rate and servo performance of perpendicular recording components, and highlights the impact of skew angle and external field on recording performance. We also report our first efforts to incorporate perpendicular components into disk drives.

  12. 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

  13. Electron beam irradiation for biological decontamination of Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Brasoveanu, Mirela [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor Street, P.O. Box MG-36, RO 76 900 Bucharest-Magurele (Romania)]. E-mail: mirela@infim.ro; Nemtanu, Monica [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor Street, P.O. Box MG-36, RO 76 900 Bucharest-Magurele (Romania); Minea, R. [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor Street, P.O. Box MG-36, RO 76 900 Bucharest-Magurele (Romania); Grecu, Maria Nicoleta [National Institute for Materials Physics, Bucharest-Magurele (Romania); Mazilu, Elena [Hofigal SA (Romania); Radulescu, Nora [Hofigal SA (Romania)

    2005-10-15

    The Cyanobacterium Spirulina is commercialized for its use in health foods and for therapeutic purposes due to its valuable constituents particularly proteins and vitamins. The aim of the paper is to study the Spirulina platensis behaviour when it is electron beam irradiated for biological decontamination. Microbial load, antioxidant activity, enzymatic inhibition, electron spin resonance (ESR) and UV-Vis spectra were measured for doses up to 80 kGy. The results were correlated with doses in order to find where decontamination is efficient, keeping the Spirulina qualities.

  14. Effect of cobalt on the primary productivity of Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R.M.; Panigrahi, S.; Azeez, P.A.

    1987-10-01

    Cobalt, a micronutrient for biological organisms, is a metal of wide use. Main sources of Co to the environment are combustion of fossil fuels, smelters, cobalt processing facilities, sewage and industrial wastes. Atomic power plants and nuclear weapon detonations form an important source of radioisotopes of this metal to the environment. Cobalt has been included in the 14 toxic trace elements of critical importance from the point of view of environmental pollution and health hazards. Cobalt deficiency leads to diseases like stunted growth. At toxic level, Co inhibits heme biosynthesis and enzyme activities. The present study reports the effect of cobalt on biomass productivity of blue-green alga Spirulina platensis.

  15. MERCURY ADSORPTION BY ARTHOBACTER GLOBIFORMIS AND SPIRULINA PLATENSIS

    Directory of Open Access Journals (Sweden)

    T. L. Kalabegishvili

    2011-06-01

    Full Text Available The increasing contamination of soil, sediment, and water with heavy metals by natural and industrial processes is a worldwide problem. Many bacteria and microalgae have demonstrated ability to absorb toxic elements. To study mercury biosorption by bacteria Arthrobacter globiformis and microalga Spirulina platensis neutron activation analysis (NAA was applied. The process of mercury biosorption by these media was described by Freundlich and Langmuir-Freundlich Model. Both microorganisms showed a great potential to be used as biosorbing agents for mercury removal from the environment.

  16. Electron beam irradiation for biological decontamination of Spirulina platensis

    Science.gov (United States)

    Brasoveanu, Mirela; Nemtanu, Monica; Minea, R.; Grecu, Maria Nicoleta; Mazilu, Elena; Radulescu, Nora

    2005-10-01

    The Cyanobacterium Spirulina is commercialized for its use in health foods and for therapeutic purposes due to its valuable constituents particularly proteins and vitamins. The aim of the paper is to study the Spirulina platensis behaviour when it is electron beam irradiated for biological decontamination. Microbial load, antioxidant activity, enzymatic inhibition, electron spin resonance (ESR) and UV-Vis spectra were measured for doses up to 80 kGy. The results were correlated with doses in order to find where decontamination is efficient, keeping the Spirulina qualities.

  17. Cultivo da microalga spirulina platensis em fontes alternativas de nutrientes Culture of microalga Spirulina platensis in alternative sources of nutrients

    Directory of Open Access Journals (Sweden)

    Michele da Rosa Andrade

    2008-10-01

    Full Text Available O Brasil gera cerca de 18 milhões de toneladas de melaço por ano, com aproximadamente 50% de açúcares e carece de maior quantidade de alimentos que auxiliem no combate à desnutrição. Spirulina platensis é uma microalga que pode conter 74% de proteínas e, embora seja um microrganismo autotrófico, a complementação do meio de cultivo com carbono orgânico pode estimular seu crescimento. S. platensis foi cultivada em modo autotrófico com bicarbonato de sódio, e mixotrófico com 0,25; 0,50; 0,75 e 1,00 g.L-1 de melaço em pó (MEP ou melaço líquido (MEL. A presença de MEL ou MEP resultou em crescimento por, no mínimo 35 dias, e melhores parâmetros de crescimento que os cultivos autotróficos que cresceram durante 30 dias. Utilizando ME P 0,25 g.L-1 a maior concentração de biomassa foi 2,59 g.L-1 e produtividade 0,066 g.L-1.dia-1, enquanto cultivos autotróficos alcançaram 1,44 g.L-1 e 0,045 g.L-1.dia-1. A máxima concentração de biomassa (2,83 g.L-1 e produtividade (0,098 g.L-1.dia-1 foram obtidas em MEL 0,50 g.L-1. Os resultados demonstram que o potencial brasileiro de produção de melaço pode ser explorado também para obtenção de altas concentrações de biomassa no cultivo da microalga Spirulina platensis.Brazil produces approximately 18,000,000 tons of molasses per year, containing 50% of sugars. This country needs more food help for the malnourishment disease. Spirulina platensis is a microalga that contains up to 74% proteins. It grows photoautotrophically, but the medium complementation with organic carbon may stimulate its growth. S. platensis was grown autotrophically and mixotrofically with 0.25; 0.50; 0.75 and 1.00 g.L-1 of powder molasses (MEP or liquid molasses (MEL. Cultures with MEL or MEP have grown for more long time (minimum 35 days and have reached higher biomass concentration and productivity than autotrophic one, that grew during 30 days. Cultures with MEP 0.25 g.L-1 have reached biomass concentration

  18. Formulation of Red Seaweed and Spirulina platensis Based Jelly Drinks

    Directory of Open Access Journals (Sweden)

    Wini Trilaksani

    2015-06-01

    Full Text Available Generally, jelly drinks in the market contain synthetic sweeteners, coloring and flavoring agents, as well as low in nutrients content, therefore it needs to be developed in order to obtain more healthy product by adding seaweed and Spirulina. The aims of this research were to determine the best formula of jelly drinks with seaweed (Eucheuma cottonii and Spirulina platensis and to compare the characteristics (nutrients and antioxidant activity of jelly drinks made from culture-based Spirulina and from commercial Spirulina. Jelly drinks made from commercial Spirulina (0.2%; 0.4%; and 0.6% had protein content 1.218-2.750% (db and the IC50 value was 3363.5-6070 ppm. Bayes test showed that jelly drink with commercial Spirulina 0.4% was the selected product and was used as the reference formula on this research. Types of Spirulina (commercial and culture gave no significant effect (p>0.05 to the hedonic test results and antioxidant activity however affected significantly on protein content (p<0.05. Jelly drink supplemented with 0.4% of culture-based Spirulina produced 92 kcal of energy; meanwhile the jelly drink with 0.4% of commercial Spirulina produced 79 kcal of energy. Keywords: Dietary fiber, jelly drink, protein, seaweed, Spirulina platensis

  19. OPTIMALISASI EKSTRAKSI DAN UJI STABILITAS PHYCOCYANIN DARI MIKROALGA Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Bakti Jos

    2012-02-01

    Full Text Available The growing awareness of the importance of natural colours especially food and cosmetic colorants has placedgreat demand on biological sources of natural colours. It is for this reason that the phycobiliproteins inSpirulina platensis is gaining increasing attention as an alternative colour for these products. Numerousscientific reports confirm the fact that Phycocyanin from Spirulina platensis, is not only an effective naturalblue colorant, but also a compound that is beneficial to the health of the consumer. The aim of this research is toconduct evaluation studies phycocyanin production by extraction with polar solvents at various concentrationsto obtain extracts for maximum yield. The methods in this study has several stages, namely preparation ofmaterials, extraction, solubility studies of phycocyanin, phycocyanin’s stability test. Changing variables in thisstudy are water, acetic acid 70%, 75%, 80%, ammonium sulphate 50%, 55%, 60%. The analysis of the extractsof phycocyanin’s content using spectrophotometric methods. The observations produces a blue pigment whichhas the highest color intensity with maximum absorbance of 620 nm. Acetic acid 80% is the most effectivesolvent to extract the blue pigment phycocyanin than water and ammonium sulfate. Extraction is influenced bythe pH of the increase in absorption (absorbance with increasing pH and was not influenced by storagetemperature and time

  20. A new model of phycobilisome in Spirulina platensis

    Institute of Scientific and Technical Information of China (English)

    张玉忠; 陈秀兰; 周百成; 曾呈奎; 刘洁; 时东霞; 庞世瑾

    1999-01-01

    Phycobilisomes (PBS) were isolated from blue-green alga Spirulina platensis. Scanning tunneling microscope was used to investigate the three-dimensional structure of PBS deposited on freshly cleaved highly oriented py-rolytic graphite (HOPG) in ambient condition at room temperature. The results showed that the rods of PBS radiated from the core to different directions in the space other than arrayed in one plane, which was different from the typical hemi-discoidal model structure. The diameter of PBS was up to 70 nm, and the rod was approximately 50 nm in length. Similar results were observed in Langmuir-Blodgett (LB) film of PBS. The dissociated PBS could reaggregate into rod-like structures and easily form two-dimensional membrane while being absorbed on HOPG, however, no intact PBS was observed. The filling-space model structure of PBS in Spirulina platensis with STM from three-dimensional real space at nanometer scale was found, which showed that this new structural model of PBS surely exists in blue

  1. A new model of phycobilisome in Spirulina platensis.

    Science.gov (United States)

    Zhang, Y; Chen, X; Zhou, B; Zeng, C; Liu, J; Shi, D; Pang, S

    1999-02-01

    Phycobilisomes (PBS) were isolated from blue-green alga Spirulina platensis. Scanning tunneling microscope was used to investigate the three-dimensional structure of PBS deposited on freshly cleaved highly oriented pyrolytic graphite (HOPG) in ambient condition at room temperature. The results showed that the rods of PBS radiated from the core to different directions in the space other than arrayed in one plane, which was different from the typical hemi-discoidal model structure. The diameter of PBS was up to 70 nm, and the rod was approximately 50 nm in length. Similar results were observed in Langmuir-Blodgett (LB) film of PBS. The dissociated PBS could reaggregate into rod-like structures and easily form two-dimensional membrane while being absorbed on HOPG, however, no intact PBS was observed. The filling-space model structure of PBS in Spirulina platensis with STM from three-dimensional real space at nanometer scale was found, which showed that this new structural model of PBS surely exists in blue-green algae and red algae. The function of this structural model of PBS was also discussed.

  2. In vitro and in vivo preliminary results on Spirulina platensis for ...

    African Journals Online (AJOL)

    user

    2013-05-01

    May 1, 2013 ... of squalane in methanolic extract of Spirulina most probably are the causes of its higher antimicrobial activity. Key words: Staphylococcus aureus, impetigo, Spirulina platensis, ...... Molecular mechanisms in C-Phycocyanin.

  3. Biosorption of Ag(I)-Spirulina platensis for different pH

    CERN Document Server

    Gelagutashvili, E; Kuchava, N; Bagdavadze, N; Rcheulishvili, A

    2011-01-01

    Biosorption of Ag(I)-Spirulina platensis for different pH were investigated using dialysis and Atomic-absorbtion analysis. It was shown, that the biosorption constant for Ag(I) Spirulina platensis complex and the capacity depend on the change of pH. In particular, with the increase of pH (pH=5.5. and pH=8.6 cases), the biosorption constant increase and the capacity decreases. The nature of interaction is also changed. In case of neutral pH, the interaction Ag(I)-S. platensis is of cooperative character and maximum metal biosorption by S. platensis biomass was observed at pH 7.0.

  4. Spirulina platensis is more efficient than Chlorella homosphaera in carbohydrate productivity.

    Science.gov (United States)

    Margarites, Ana Cláudia; Volpato, Noany; Araújo, Elenara; Cardoso, Luana Garbin; Bertolin, Telma Elita; Colla, Luciane Maria; Costa, Jorge Alberto Vieira

    2016-11-21

    This study aimed to compare the production of biomass with high carbohydrate content by Spirulina platensis LEB 52 and Chlorella homosphaera microalgae. The cultivation of C. homosphaera and S. platensis LEB 52 was performed in standard medium diluted at 50%, and glucose was added as a source of organic carbon for mixotrophic metabolism. The sodium nitrate concentration was increased and the nitrogen components were reduced in the media to induce the synthesis of carbohydrates. C. homosphaera and S. platensis LEB 52 produced 16.32 and 116 mg L(-1) of carbohydrates per day, respectively, when cultivated with 50% less nitrogen and 20% and 10% more sodium chloride, compared with the control. Glucose addition was an essential factor for microalgal growth, resulting in biomass increases of up to 2.79- and 3.45-fold for C. homosphaera and S. platensis LEB 52, respectively. Spirulina presented better characteristics than Chlorella with regard to the capacities of growth and carbohydrate synthesis.

  5. Isolation and characterization of two ferredoxin-NADP+ reductases from Spirulina platensis.

    Science.gov (United States)

    Masaki, R; Wada, K; Matsubara, H

    1979-10-01

    Two ferredoxin-NADP+ reductases (FNRs I and II) [EC 1.6.7.1] were purified from a blue-green alga, Spirulina platensis, by (NH4)2SO4 fractionation, gel filtration on Sephadex G-100 and DEAE-Sephadex A-50 chromatography. FNRs I and II were both FAD-containing enzymes with molecular weights of 33,000, and could photochemically reduce NADP+ to the same extent in the presence of S. platensis ferredoxin, using FNR-depleted membrane fragments of S. platensis. They had similar physical and enzymatic properties, except for chemical properties such as the amino (N)-terminal sequences and the patterns of their peptide maps. The significance of the presence of two FNRs in S. platensis as as of the multiple forms found in other organisms is discussed.

  6. Proteome-Wide Analysis and Diel Proteomic Profiling of the Cyanobacterium Arthrospira platensis PCC 8005

    OpenAIRE

    2014-01-01

    The filamentous cyanobacterium Arthrospira platensis has a long history of use as a food supply and it has been used by the European Space Agency in the MELiSSA project, an artificial microecosystem which supports life during long-term manned space missions. This study assesses progress in the field of cyanobacterial shotgun proteomics and light/dark diurnal cycles by focusing on Arthrospira platensis. Several fractionation workflows including gel-free and gel-based protein/peptide fractionat...

  7. Inhibitory effects of polysaccharide extract from Spirulina platensis on corneal neovascularization

    OpenAIRE

    Yang, LingLing; Wang, Yao; Zhou, Qingjun; Chen, Peng; Wang, Yiqiang; Wang, Ye; Liu, Ting; Xie, Lixin

    2009-01-01

    Purpose To assess the effects of polysaccharide extract from Spirulina platensis (PSP) on corneal neovascularization (CNV) in vivo and in vitro. Methods PSP was extracted from dry powder of Spirulina platensis. Its anti-angiogenic activity was evaluated in the mouse corneal alkali burn model after topical administration of PSP four times daily for up to seven days. Corneal samples were processed for histochemical, immunohistochemical, and gene expression analyses. The effects of PSP on prolif...

  8. Cultivation of Arthrospira (Spirulina) platensis using confectionary wastes for aquaculture feeding

    OpenAIRE

    Hala Y. El-Kassas; Ahmed M.M. Heneash; Nabila R. Hussein

    2015-01-01

    The microalga biomass production from confectionary effluent is a possible solution for the urgent need for a live food in aquaculture. Arthrospira (Spirulina) platensis was the dominant alga in effluent of “Biscomisr a confectionary factory”, in Alexandria–Egypt. Therefore, it was isolated from the effluent samples and used throughout the study. The cyanobacterium, A. platensis was grown on the effluent using 22 Central Composite Design (22 CCD). This work addresses the best effluent dilutio...

  9. Perpendicular ion acceleration in whistler turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Saito, S. [Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8601 (Japan); Nariyuki, Y. [Faculty of Human Development, University of Toyama, 3190, Toyama 930-8555 (Japan)

    2014-04-15

    Whistler turbulence is an important contributor to solar wind turbulence dissipation. This turbulence contains obliquely propagating whistler waves at electron scales, and these waves have electrostatic components perpendicular to the mean magnetic field. In this paper, a full kinetic, two-dimensional particle-in-cell simulation shows that whistler turbulence can accelerate ions in the direction perpendicular to the mean magnetic field. When the ions pass through wave-particle resonances region in the phase space during their cyclotron motion, the ions are effectively accelerated in the perpendicular direction. The simulation results suggest that whistler turbulence contributes to the perpendicular heating of ions observed in the solar wind.

  10. Stimulation of Deprivation Cycles with Spirulina platensis Feed Supplementation on Osphronemus gouramy Physiological Responses

    Directory of Open Access Journals (Sweden)

    Sorta Basar Ida Simanjuntak

    2016-11-01

    Full Text Available Spirulina platensis is a phytoplankton, the cell wall composed of complex sugars so easily digested by fish. The present study was carried out to investigate stimulation cycle of feed deprivation with feed supplemented S. platensis the best to increase growth, hematological and body composition of gurami (Osphronemus gouramy. Groups of 24 fish, each in triplicate, were exposed to four different treatment for a period of 56 days. Sample measurements of growth done every 14 days, hematological and body composition measurements carried out at the end of the experiment. Growth was significantly different between stimulation cycle of feed deprivation and the control (P<0.05. Conclusions result showed that stimulation cycles of feed deprivation could not improve growth and hematological, but could improve body composition. Feed deprivation is done to reduce the cost of production, high production costs due to high feed prices. During research on feed deprivation is done by giving commercial feed, this study is to provide feed supplementation S. platensis. Thus, the results of this study can be useful for science as S. platensis information can be used as a food supplement and and for the people cultivating gurami should be fed daily supplementation of S. platensis.How to CiteSimanjuntak, S. B. I., Wibowo, E. S. & Indarmawan, I. (2016. Stimulation of Deprivation Cycles with Spirulina platensis Feed Supplementation on Osphronemus gouramy Physiological Responses. Biosaintifika: Journal of Biology & Biology Education, 8(3,  378-385. 

  11. Extraction of Bioactive Compounds as Natural Antioxidants from Fresh Spirulina platensis using Different Solvents

    Directory of Open Access Journals (Sweden)

    Fiya Firdiyani

    2015-06-01

    Full Text Available Spirulina platensis is a bioactive-rich microalga of great potential as a source of natural antioxidant. Natural antioxidants are increasing in demand, because it is considered as more safe than synthetic antioxidants. The objective of this study was to determine the effect of solvent on the potential of natural antioxidant from fresh S. platensis. The antioxidant compound was extracted using either acetone or ethyl acetate by reflux method. The yield of extractions were 1.86% and 3.07% for aceton and ethyl acetate, respectively. Fresh S. platensis extracts were considered as potential antioxidant source with IC50 values 65.89 ppm, and 76.36 ppm when using acetone and ethyl acetate, respectivetly, even though it were still lower compare to the IC50 of positive control quercetin i.e 21.64 ppm. Phytochemical test showed positive results of phenolic compound, triterpenoids, steroid, flavanoid, and saponin. aw value of Spirulina platensis was 0.61 and 0.81 for aceton and ethyl acetate, respectively. It was concluded that different solvent affected the antioxidant activity of S. platensis extract. Keywords: Antioxidants, aceton, ethyl acetate, fresh Spirulina platensis

  12. Analysis on promoter elements of cpc operon from Arthrospira platensis

    Institute of Scientific and Technical Information of China (English)

    LU Yongzhong; ZHANG Xuecheng

    2008-01-01

    On the basis of bioinformatics analysis,six putative promoters were isolated from the upstream sequence of c-phycocyanin gene of Arthrospira platensis FACHB341 through site-directed mutagenesis,and the transcriptional pattern of c-phycocyanin gene was de- termined by SmartRace.Results showed that each isolated promoter drived the expression of gfp in E.coli,and Promoter Ⅲ was the strongest one according to the GFP level.Only one transcript of c-phycocyanin gene was found under experimental conditions, and the transcription start site G was located at the-285 bp upstream of the start cedon,from which it could be inferred that the transcript was from the promotion of Promoter Ⅰ.

  13. C-phycocyanin extraction from Spirulina platensis wet biomass

    Directory of Open Access Journals (Sweden)

    C. C. Moraes

    2011-03-01

    Full Text Available C-Phycocyanin is a natural blue dye used in food and pharmaceutical industry. In the present study, a simple and efficient method to extract C-phycocyanin from Spirulina platensis wet biomass is reported. The extractions were carried out using six different methods, including chemical (organic and inorganic acid treatment, physical (freezing and thawing, sonication, homogenization and enzymatic (lysozyme treatment methods. The extraction using ultrasonic bath in the presence of glass pearls in the biomass proved to be the most efficient method, 56% higher than using freezing and thawing (the method most frequently used, and presented a extraction yield of 43.75 mg.g-1 and a C-phycocyanin concentration of 0.21 mg.mL-1.

  14. Culture of the cyanobacteria Spirulina platensis using synthetic swine wastewater

    OpenAIRE

    Tanise Boeira Pelegrini Bertolin; Jorge Alberto Vieira Costa; Telma Elita Bertolin; Luciane Maria Colla; Marcelo Hemkemeier

    2005-01-01

    Estudou-se o cultivo da cianobactéria Spirulina platensis utilizando-se efluente sintético de suíno a fim de avaliar o crescimento das cepas LEB 52 e PARACAS dessa cianobactéria, em função da diluição do meio (0 e 50%) e da concentração de bicarbonato de sódio (0 e 3g/L). Nesta etapa foi utilizado um Planejamento Fatorial Completo 2³. Na Segunda etapa, diluiu-se o meio em 80, 50 e 20% e utilizou-se um Planejamento Fatorial Multiníveis 3¹ x 2¹. Os cultivos foram realizados a 30°C, com fotoperí...

  15. [Carbonic anhydrase of blue-green alga Spirulina platensis].

    Science.gov (United States)

    Komarova, Iu M; Terekhova, I V; Doman, N G; Al'bitskaia, O N

    1976-01-01

    Carboanhydrase (carbonate-hydroliase EC 4.2.1.1.) is found in the extract of Spirulina platensis cells. A linear dependency of the enzyme activity on the protein concentration; pH optimum is found to be 8.0. Specific activity of carboanhydrase is 3 muM/min-mg of protein under the concentration of CO2 of 4-10(-3) M, appearing Michelis constant being 4.9-10(-3) M. The enzyme was stabilized with 10 mM of cisteine, its activity was inhibited by 50% with sulphanylamide (1-10(-5) M), acetazolamide (8--10(-7) M) and Cl- ions (5-10(-2) M). The activity of carboanhydrase, as well as the rate of NaH14CO3 fixation, depended on the pH value of cultural medium.

  16. Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

    Directory of Open Access Journals (Sweden)

    G. L. Dotto

    2013-03-01

    Full Text Available The equilibrium and thermodynamics of azo dye (tartrazine and allura red biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium experimental data (R²>0.99 and ARE<5.0% and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

  17. Cultivation of an Arthrospira platensis with digested piggery wastewater.

    Science.gov (United States)

    Liu, Rui; Guo, Qingqing; Zheng, Wei; Chen, Lüjun; Luo, Jinfei

    2015-01-01

    An Arthrospira platensis strain ZJWST-S1 was isolated in Jiaxing City, China, which proved able to proliferate quickly in undiluted digested piggery wastewater (DPW), and the protein content in the algal biomass was high. Single factor experiments showed that the strain was able to quickly grow in a Zarrouk medium as the dosage of sodium bicarbonate, nitrate-nitrogen and phosphate-phosphorus was not less than 4.0 mg·L(-1), 40 mg·L(-1) and 10 mg·L(-1), respectively. No growth inhibition was observed when the culturing medium contained nitrite nitrogen of 0-120 mg·L(-1) and ammonium nitrogen of below 20 mg·L(-1). Five runs of semi-continuous cultivation with DPW as the culturing medium in a 250 L raceway pond showed that the biomass yield in a 9-day semi-continuous culturing was up to 45.2-64.7 g·m(-2)·d(-1), higher than the yields obtained by other researchers, and the crude protein content in biomass was over 50%, meeting the national animal feed grade standard. Total nitrogen (TN) and total phosphorus (TP) were removed from DPW at a rate of 10.9-14.0 mg·L(-1)·d(-1) and 1.3-1.8 mg·L(-1)·d(-1), respectively. The mass balance revealed that 80-93% of TN and 84-98% of TP reduced from DPW were converted to A. platensis biomass.

  18. Effects of Chemical Parameters on Spirulina platensis Biomass Production: Optimized Method for Phycocyanin Extraction

    Directory of Open Access Journals (Sweden)

    B. Vasanthi

    2008-01-01

    Full Text Available The micro alga, Spirulina is a rich source of protein, which is used as a protein supplement for humans, chicks and also in aquaculture. Among the cultures, CS-1 registered maximum biomass production and S-20 showed highest biomass production among the local isolates. Optimum temperature of 35C was the best for maximum biomass production of S. platensis cultures. Among the cultures CS-1 culture, put forth maximum biomass production at 35C. The biomass production of all S. platensis cultures was maximum at pH 10.0. Among the cultures, CS-1 recorded maximum biomass at pH 10.0. S. platensis culture S-20 showed highest biomass production among the local isolates. S. platensis cultures were grown under different light wave lengths ranging from 340-700 nm and observed that it grows best in red light but later on there was no significant difference between the biomass produced under red and normal white lights. S. platensis culture CS-1 has shown the highest chlorophyll, carotenoids and phycocyanin and protein contents. When the extracted protein was resolved on a 15% SDS-PAGE gel, the cultures have polypeptide subunits ranging from the molecular weights 20 to 95 kDa. The liquid nitrogen method was found to be the best by extraction higher quantity of phycocyanin from all S. platensis cultures. Among the cultures, S. platensis culture CS-1 recorded the highest phycocyanin content and among the local isolates SM-2 showed the highest pigment content. SDS-PAGE analysis of phycocyanin pigment revealed two characteristic bands with a molecular weights of 14.3 and 20.1 kDa approximately for a and subunits.

  19. Technological and nutritional assessment of dry pasta with oatmeal and the microalga Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Fernanda Arnhold Pagnussatt

    2014-12-01

    Full Text Available Wheat flour is the most important raw material in the production of pasta. The production process consists of mixing water and flour, kneading, extrusion and drying. Oats and the microalga Spirulina platensis play a physiological role in the growth, development and maintenance of the human organism due to their high nutritional value. The aim of this study was to assess the technological and nutritional properties of dry pasta prepared with the addition of oatmeal and Spirulina platensis. The wheat flour was characterized and the effect of partial replacement by oatmeal and Spirulina platensis (Arthrospira platensis was evaluated using response surface methodology (RSM. The mixtures were analysed for moisture, protein, ash, colour, particle size, falling number and alveography. The formulated pastas were dried and evaluated for moisture, colour, cooking test, acidity, proximate composition and amino acids. Generally, the addition of Spirulina platensis influenced the soluble solids content and colour of the pasta, while the oatmeal mainly affected the acid content. The oatmeal increased the values of crude protein and total dietary fibre (13.06% when compared with the commercial pasta (2.40% and may be considered as a source of fibre.

  20. Semicontinuous cultivation of the cyanobacterium Spirulina platensis in a closed photobioreactor

    Directory of Open Access Journals (Sweden)

    C. C. Reichert

    2006-03-01

    Full Text Available The cultivation of photosynthetic microorganisms such as the cyanobacterium Spirulina platensis has been studied by researchers in many countries because these organisms can produce products with industrial potential. We studied the specific growth rate (µx, day-1 and productivity (Px, in mg/L/day of Spirulina platensis biomass, dry weight basis of two S. platensis strains (LEB-52 and Paracas growing in aerated semicontinuous culture in two-liter Erlenmeyer flasks for 90 days (2160 h at 30°C under 2500 lux of illumination in a 12 h photoperiod. Independent of the S. platensis strain used we found that low biomass concentrations (0.50 g/L and high renewal rates (50% v/v resulted in a high specific growth rate (µx = 0.111 day-1 and high productivity (Px = 42.3 mg/L/day. These values are two to four times higher than those obtained in simple batch cultivation and indicate that the semicontinuous cultivation of S. platensis is viable.

  1. Semicontinuous cultivation of the Cyanobacterium Spirulina platensis in a closed photobioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, C.C.; Costa, J.A.V. [Fundacao Universidade Federal do Rio Grande (FURG), Rio Grande, RS (Brazil). Dept. de Quimica], Email: dqmjorge@furg.br; Reinehr, C.O. [Universidade de Passo Fundo, RS (Brazil). Centro de Pesquisa em Alimentacao], Email: reinehr@upf.br

    2006-01-15

    The cultivation of photosynthetic microorganisms such as the cyanobacterium Spirulina platensis has been studied by researchers in many countries because these organisms can produce products with industrial potential. We studied the specific growth rate ({mu}{sub x}, day{sup -1}) and productivity (P{sub x}, in mg/L/day of Spirulina platensis biomass, dry weight basis) of two S. platensis strains (LEB-52 and Paracas) growing in aerated semicontinuous culture in two-liter Erlenmeyer flasks for 90 days (2160 h) at 30 deg C under 2500 lux of illumination in a 12 h photoperiod. Independent of the S. platensis strain used we found that low biomass concentrations (0.50 g/L) and high renewal rates (50% v/v) resulted in a high specific growth rate ({mu}{sub x} = 0.111 day{sup -1}) and high productivity (P{sub x} = 42.3 mg/L/day). These values are two to four times higher than those obtained in simple batch cultivation and indicate that the semicontinuous cultivation of S. platensis is viable. (author)

  2. Removal of heavy metals from tannery effluents of Ambur industrial area, Tamilnadu by Arthrospira (Spirulina) platensis.

    Science.gov (United States)

    Balaji, S; Kalaivani, T; Rajasekaran, C; Shalini, M; Vinodhini, S; Priyadharshini, S Sunitha; Vidya, A G

    2015-06-01

    The present study was carried out with the tannery effluent contaminated with heavy metals collected from Ambur industrial area to determine the phycoremediation potential of Arthrospira (Spirulina) platensis. Two different concentrations (50 and 100 %) of heavy metals containing tannery effluent treated with A. platensis were analysed for growth, absorption spectra, biochemical properties and antioxidant enzyme activity levels. The effluent treatments revealed dose-dependent decrease in the levels of A. platensis growth (65.37 % for 50 % effluent and 49.32 % for 100 % effluent), chlorophyll content (97.43 % for 50 % effluent and 71.05 % for 100 % effluent) and total protein content (82.63 % for 50 % effluent and 62.10 % for 100 % effluent) that leads to the reduction of total solids, total dissolved solids and total suspended solids. A. platensis with lower effluent concentration was effective than at higher concentration. Treatment with the effluent also resulted in increased activity levels of antioxidant enzymes, such as superoxide dismutase (14.58 units/g fresh weight for 50 % and 24.57 units/g fresh weight for 100 %) and catalase (0.963 units/g fresh weight for 50 % and 1.263 units/g fresh weight for 100 %). Furthermore, heavy metal content was determined using atomic absorption spectrometry. These results indicated that A. platensis has the ability to combat heavy metal stress by the induction of antioxidant enzymes demonstrating its potential usefulness in phycoremediation of tannery effluent.

  3. Extraction of Bioactive Compounds as Natural Antioxidants from Fresh Spirulina platensis using Different Solvents

    Directory of Open Access Journals (Sweden)

    Fiya Firdayani

    2015-06-01

    Full Text Available Spirulina platensis is a bioactive-rich microalga of great potential as a source of natural antioxidant. Natural antioxidants are increasing in demand, because it is considered as more safe than synthetic antioxidants. The objective of this study was to determine the effect of solvent on the potential of natural antioxidant from fresh S. platensis. The antioxidant compound was extracted using either acetone or ethyl acetate by reflux method. The yield of extractions were 1.86% and 3.07% for aceton and ethyl acetate, respectively. Fresh S. platensis extracts were considered as potential antioxidant source with IC50 values 65.89 ppm, and 76.36 ppm when using acetone and ethyl acetate, respectivetly, even though it were still lower compare to the IC50 of positive control quercetin i.e 21.64 ppm. Phytochemical test showed positive results of phenolic compound, triterpenoids, steroid, flavanoid, and saponin. aw value of Spirulina platensis was 0.61 and 0.81 for aceton and ethyl acetate, respectively. It was concluded that different solvent affected the antioxidant activity of S. platensis extract.

  4. Arsenic methylation by an arsenite S-adenosylmethionine methyltransferase from Spirulina platensis.

    Science.gov (United States)

    Guo, Yuqing; Xue, Ximei; Yan, Yu; Zhu, Yongguan; Yang, Guidi; Ye, Jun

    2016-11-01

    Arsenic-contaminated water is a serious hazard for human health. Plankton plays a critical role in the fate and toxicity of arsenic in water by accumulation and biotransformation. Spirulina platensis (S. platensis), a typical plankton, is often used as a supplement or feed for pharmacy and aquiculture, and may introduce arsenic into the food chain, resulting in a risk to human health. However, there are few studies about how S. platensis biotransforms arsenic. In this study, we investigated arsenic biotransformation by S. platensis. When exposed to arsenite (As(III)), S. platensis accumulated arsenic up to 4.1mg/kg dry weight. After exposure to As(III), arsenate (As(V)) was the predominant species making up 64% to 86% of the total arsenic. Monomethylarsenate (MMA(V)) and dimethylarsenate (DMA(V)) were also detected. An arsenite S-adenosylmethionine methyltransferase from S. platensis (SpArsM) was identified and characterized. SpArsM showed low identity with other reported ArsM enzymes. The Escherichia coli AW3110 bearing SparsM gene resulted in As(III) methylation and conferring resistance to As(III). The in vitro assay showed that SpArsM exhibited As(III) methylation activity. DMA(V) and a small amount of MMA(V) were detected in the reaction system within 0.5hr. A truncated SpArsM derivative lacking the last 34 residues still had the ability to methylate As(III). The three single mutants of SpArsM (C59S, C186S, and C238S) abolished the capability of As(III) methylation, suggesting the three cysteine residues are involved in catalysis. We propose that SpArsM is responsible for As methylation and detoxification of As(III) and may contribute to As biogeochemistry. Copyright © 2016. Published by Elsevier B.V.

  5. A pilot-scale floating closed culture system for the multicellular cyanobacterium Arthrospira platensis NIES-39.

    Science.gov (United States)

    Toyoshima, Masakazu; Aikawa, Shimpei; Yamagishi, Takahiro; Kondo, Akihiko; Kawai, Hiroshi

    Microalgae are considered to be efficient bio-resources for biofuels and bio-based chemicals because they generally have high productivity. The filamentous cyanobacterium Arthrospira (Spirulina) platensis has been widely used for food, feed, and nutrient supplements and is usually cultivated in open ponds. In order to extend the surface area for growing this alga, we designed a pilot-scale floating closed culture system for cultivating A. platensis on open water and compared the growth and quality of the alga harvested at both subtropical and temperate regions. The biomass productivity of A. platensis NIES-39 was ca. 9 g dry biomass m(-2) day(-1) in summer at Awaji Island (warm temperature region) and ca. 10 and 6 g dry biomass m(-2) day(-1) in autumn and winter, respectively, at Ishigaki Island, (subtropical region) in Japan. If seawater can be used for culture media, culture cost can be reduced; therefore, we examined the influence of seawater salt concentrations on the growth of A. platensis NIES-39. Growth rates of A. platensis NIES-39 in diluted seawater with enrichment of 2.5 g L(-1) NaNO3, 0.01 g L(-1) FeSO4·7H2O, and 0.08 g L(-1) Na2EDTA were considerably lower than SOT medium, but the biomass productivity (dry weight) was comparable to SOT medium. This is explained by the heavier cell weight of the alga grown in modified seawater media compared to the alga grown in SOT medium. Furthermore, A. platensis grown in modified seawater-based medium exhibited self-flocculation and had more loosely coiled trichomes.

  6. Effects of N source and nitrification pretreatment on growth of Arthrospira platensis in human urine

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Culture of Arthrospira platensis (Spirulina platensis) in human urine was investigated to get valuable biomass. NO3-N was the proper N source, in comparison with other N source, includ ing urea, NH4-N and NO2-N. As a result, aerobic nitrification of human urine was performed, with above 93.6% nitrification percentage finally achieved with total-N (TN) load of 46.52those in Zarrouk medium. Thus, it is possible to culture Arthrospiraplatensis in nitrified human urine for food production within bioregenerative life support systems (BLSSs).

  7. Hydrogen ions directly regulating the oligomerization state of Photosystem I in intact Spirulina platensis cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    H+ concentration induced-monomerization or trimerization of photosystem I (PSI) in cyanobacteria has never been directly observed. In this work, taking characteristic spectra for the trimers and monomers as the indicators, it was experimentally demonstrated that H+ could induce the oligomeric changes of PSI reaction centers in the intact Spirulina ,platensis cells and also in the isolated thylakoid membrane complexes. Especially, the higher concentration of H+ would induce the monomerization while the lower the trimerization, suggesting the electrostatic interaction should be mainly responsible forchanges in the oligomeric state of PSI in Spirulina platensis.

  8. Culture of Spirulina platensis in human urine for biomass production and O2 evolution

    Institute of Scientific and Technical Information of China (English)

    Feng Dao-lun; WU Zu-cheng

    2006-01-01

    Attempts were made to culture Spirulina platensis in human urine directly to achieve biomass production and O2 evolution, for potential application to nutrient regeneration and air revitalization in life support system. The culture results showed that Spirulinaplatensis grows successfully in diluted human urine, and yields maximal biomass at urine dilution ratios of 140~240.Accumulation of lipid and decreasing of protein occurred due to N deficiency. O2 release rate of Spirulina platensis in diluted human urine was higher than that in Zarrouk medium.

  9. Formulation of Red Seaweed and Spirulina platensis Based Jelly Drinks

    Directory of Open Access Journals (Sweden)

    Wini Trilaksani

    2015-06-01

    Full Text Available Generally, jelly drinks in the market contain synthetic sweeteners, coloring and flavoring agents, as well as low in nutrients content, therefore it needs to be developed in order to obtain more healthy product by adding seaweed and Spirulina. The aims of this research were to determine the best formula of jelly drinks with seaweed (Eucheuma cottonii and Spirulina platensis and to compare the characteristics (nutrients and antioxidant activity of jelly drinks made from culture-based Spirulina and from commercial Spirulina. Jelly drinks made from commercial Spirulina (0.2%; 0.4%; and 0.6% had protein content 1.218-2.750% (db and the IC50 value was 3363.5-6070 ppm. Bayes test showed that jelly drink with commercial Spirulina 0.4% was the selected product and was used as the reference formula on this research. Types of Spirulina (commercial and culture gave no significant effect (p>0.05 to the hedonic test results and antioxidant activity however affected significantly on protein content (p<0.05. Jelly drink supplemented with 0.4% of culture-based Spirulina produced 92 kcal of energy; meanwhile the jelly drink with 0.4% of commercial Spirulina produced 79 kcal of energy.

  10. Ribulose diphosphate carboxylase of the cyanobacterium Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Terekhova, I.V.; Chernyad' ev, I.I.; Doman, N.G.

    1986-11-20

    The ribulose diphosphate (RDP) carboxylase activity of the cyanobacterium Spirulina platensis is represented by two peaks when a cell homogenate is centrifuged in a sucrose density gradient. In the case of differential centrifugation (40,000 g, 1 h), the activity of the enzyme was distributed between the supernatant liquid (soluble form) and the precipitate (carboxysomal form). From the soluble fraction, in which 80-95% of the total activity of the enzyme is concentrated, electrophoretically homogeneous RDP carboxylase was isolated by precipitation with ammonium sulfate and centrifugation in a sucrose density gradient. The purified enzyme possessed greater electrophoretic mobility in comparison with the RDP carboxylase of beans Vicia faba. The molecular weight of the enzyme, determined by gel filtration, was 450,000. The enzyme consists of monotypic subunits with a molecular weight of 53,000. The small subunits were not detected in electrophoresis in polyacrylamide gel in the presence of SDS after fixation and staining of the gels by various methods.

  11. Enhanced Phycocyanin Production from Spirulina platensis using Light Emitting Diode

    Science.gov (United States)

    Bachchhav, Manisha Bhanudas; Kulkarni, Mohan Vinayak; Ingale, Arun G.

    2016-12-01

    This work investigates the performance of different cultivation conditions using Light Emitting Diode (LED) as a light source for the production of phycocyanin from Spirulina platensis. With LEDs under autotrophic conditions, red LED produced maximum amount of biomass (8.95 g/l). As compared to autotrophic cultivation with fluorescent lamp (control), cultivations using LEDs under autotrophic and mixotrophic mode significantly enhanced the phycocyanin content. For autotrophic conditions (with LED) phycocyanin content was in the range of 103-242 mg/g of dry biomass, whereas for mixotrophic conditions (0.1% glucose and LED) it was in the range of 254-380 mg/g of dry biomass. Spirulina cultivated with yellow LED under mixotrophic conditions had 5.4-fold more phycocyanin (380 mg/g of dry biomass) than control (70 mg/g of dry biomass). The present study demonstrates that the LEDs under mixotrophic conditions gave sixfold (2497 mg/l) higher yields of phycocyanin as compared to autotrophic condition under white light (415 mg/l).

  12. Enhanced Phycocyanin Production from Spirulina platensis using Light Emitting Diode

    Science.gov (United States)

    Bachchhav, Manisha Bhanudas; Kulkarni, Mohan Vinayak; Ingale, Arun G.

    2017-06-01

    This work investigates the performance of different cultivation conditions using Light Emitting Diode (LED) as a light source for the production of phycocyanin from Spirulina platensis. With LEDs under autotrophic conditions, red LED produced maximum amount of biomass (8.95 g/l). As compared to autotrophic cultivation with fluorescent lamp (control), cultivations using LEDs under autotrophic and mixotrophic mode significantly enhanced the phycocyanin content. For autotrophic conditions (with LED) phycocyanin content was in the range of 103-242 mg/g of dry biomass, whereas for mixotrophic conditions (0.1% glucose and LED) it was in the range of 254-380 mg/g of dry biomass. Spirulina cultivated with yellow LED under mixotrophic conditions had 5.4-fold more phycocyanin (380 mg/g of dry biomass) than control (70 mg/g of dry biomass). The present study demonstrates that the LEDs under mixotrophic conditions gave sixfold (2497 mg/l) higher yields of phycocyanin as compared to autotrophic condition under white light (415 mg/l).

  13. Study on the effect of different concentration of Spirulina platensis paste added into dried noodle to its quality characteristics

    Science.gov (United States)

    Agustini, T. W.; Ma'ruf, W. F.; Widayat; Wibowo, B. A.; Hadiyanto

    2017-02-01

    High nutritional content of microalgae S. platensis is very good for human health especially for its protein and β-carotene. These compounds can be used for improving quality of food from nutritional point of view. This study was designed to observe the effect of different concentration of S. platensis paste to dried noodle quality based on physical, chemical and sensory perspectives. Material used in this study was S. platensis powder obtained from CV Neoalgae, Sukoharjo. The best treatment observed from preliminary study was then used for further study and compared to control treatment (without added S. platensis paste). The dried noodle resulted was then analyzed for elasticity, chemical (β-carotene, water, protein, ash, fat and carbohydrate) and sensory (hedonic). Parametric data obtained were analyzed using t-Test while non-parametric data was analyzed using Kruskal-Wallis followed by Multiple Comparison test. The study showed that dried noodle added with 9% S. platensis paste give significant effect (Pwater, protein, ash, fat and carbohydrate and also sensory (hedonic). Dried noodle without added S. platensis paste has lower in β-carotene and protein compared to that of added S. platensis paste with the value of 0.06 mg/100 gr and 17.51 mg/100gr (β-carotene) and 8.88% and 38.6% (protein), respectively. Those, chemical composition of dried noodle added with S. platensis comply with Indonesian National Standard in term of protein, water, and ash content with sensory of 7.26 ≤ μ ≤ 7.63. Addition of S. platensis can significantly increase the nutritional of dried noodle especially protein (by 4 times) and β-carotene.

  14. Biosorption of Cr(III), Cr(VI), Cu(II) ions by intact cells of Spirulina platensis

    OpenAIRE

    Gelagutashvili, E.; Bagdavadze, N.; Rcheulishvili, A.

    2017-01-01

    The absorption characteristics of Cr(III), Cr(VI), Cu(II) ions on intact living cells Spirulina platensis (pH9.6) were studied by using a UV-VIS spectrophotometer. Also biosorption of these ions with cyanobacteria Spirulina platensis were studied using equilibrium dialysis and atomic absorption analysis.It was shown, that the absorption intensity of Spirulina platensis decreases, when Cr(III), Cr(VI), Cu(II) ions are added. Significant difference between the absorption intensity for Cu(II) Sp...

  15. The potential effects of Spirulina platensis (Arthrospira platensis on tissue protection of Nile tilapia (Oreochromis niloticus through estimation of P53 level

    Directory of Open Access Journals (Sweden)

    Mai D. Ibrahem

    2014-01-01

    Full Text Available The current study was designed to investigate the potential effect of Spirulina platensis, Arthrospira platensis, (SP on tissue protection of Nile tilapia (Oreochromis niloticus through estimation of P53 level. Five isonitrogenous and isocaloric rations containing graded levels of dried SP 5, 7.5,10, 15, and 20 g/kg diet were fed separately to five equal groups of O. niloticus fingerlings, additional control group was assigned for 3 months. Liver samples were separately collected from each group by the end of each month. The expression level of P53 showed a substantial decrease among the treated groups in a time-dependent manner. It is therefore advisable to incorporate SP in diets for tissue protection and antioxidant effects in cultured O. niloticus.

  16. Cultivation of spirulina platensis and its growth behavior controlling cultivation medium; Baiyoeki sosei no seigyo ni yoru spirulina platensis no baiyo oyobi sono zoshoku kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, K.; Fujita, K. [Babcock-Hitachi K.K., Tokyo (Japan)

    1996-01-20

    Cultivation of Spirulina platensis while controlling pH and nitrate ion in the culture medium was investigated in order to obtain a high density culture. In the cultivation of Spirulina platensis using sodium bicarbonate as a carbon source, the pH value increased during growth of Spirulina, and then the growth stopped at a pH value of more than 12. The cell concentration reached 2.2g/l by maintaining a pH range of 8.5 to 10.0 using CO2 gas without controlling the nitrate ion concentration. By controlling the pH and adding nitrate to a concentration of 2.0g/l, the cell concentration reached 4.2g/l at 350 hours. It was found that the cell concentration was about four times that of the culture without controlling pH and nitrate. 4 refs., 6 figs.

  17. The potential effects of Spirulina platensis (Arthrospira platensis) on tissue protection of Nile tilapia (Oreochromis niloticus) through estimation of P53 level

    Science.gov (United States)

    Ibrahem, Mai D.; Ibrahim, Marwa A.

    2013-01-01

    The current study was designed to investigate the potential effect of Spirulina platensis, Arthrospira platensis, (SP) on tissue protection of Nile tilapia (Oreochromis niloticus) through estimation of P53 level. Five isonitrogenous and isocaloric rations containing graded levels of dried SP 5, 7.5,10, 15, and 20 g/kg diet were fed separately to five equal groups of O. niloticus fingerlings, additional control group was assigned for 3 months. Liver samples were separately collected from each group by the end of each month. The expression level of P53 showed a substantial decrease among the treated groups in a time-dependent manner. It is therefore advisable to incorporate SP in diets for tissue protection and antioxidant effects in cultured O. niloticus. PMID:25685480

  18. Arthrospira (Spirulina) platensis supplementation affects folliculogenesis, progesterone and ghrelin levels in fattening pre-pubertal gilts

    NARCIS (Netherlands)

    Abadjieva, Desislava; Nedeva, Radka; Marchev, Yordan; Jordanova, Gergana; Chervenkov, Mihail; Dineva, Julieta; Shimkus, Almantas; Shimkiene, Aldona; Teerds, Katja; Kistanova, Elena

    2017-01-01

    The aim of the present investigation was to study the effect of Arthrospira (Spirulina) platensis supplemented diet on follicular development and related endocrine parameters, such as estradiol and progesterone levels as well as ghrelin levels in pre-pubertal gilts. Twenty-one 60-day-old Danube

  19. Bioethanol Production by Carbohydrate-Enriched Biomass of Arthrospira (Spirulina) platensis

    DEFF Research Database (Denmark)

    Markou, Giorgos; Angelidaki, Irini; Nerantzis, Elias

    2013-01-01

    In the present study the potential of bioethanol production using carbohydrate-enriched biomass of the cyanobacterium Arthrospira platensis was studied. For the saccharification of the carbohydrate-enriched biomass, four acids (H2SO4, HNO3, HCl and H3PO4) were investigated. Each acid were used at...

  20. Proteome-wide analysis and diel proteomic profiling of the cyanobacterium Arthrospira platensis PCC 8005.

    Directory of Open Access Journals (Sweden)

    Sabine Matallana-Surget

    Full Text Available The filamentous cyanobacterium Arthrospira platensis has a long history of use as a food supply and it has been used by the European Space Agency in the MELiSSA project, an artificial microecosystem which supports life during long-term manned space missions. This study assesses progress in the field of cyanobacterial shotgun proteomics and light/dark diurnal cycles by focusing on Arthrospira platensis. Several fractionation workflows including gel-free and gel-based protein/peptide fractionation procedures were used and combined with LC-MS/MS analysis, enabling the overall identification of 1306 proteins, which represents 21% coverage of the theoretical proteome. A total of 30 proteins were found to be significantly differentially regulated under light/dark growth transition. Interestingly, most of the proteins showing differential abundance were related to photosynthesis, the Calvin cycle and translation processes. A novel aspect and major achievement of this work is the successful improvement of the cyanobacterial proteome coverage using a 3D LC-MS/MS approach, based on an immobilized metal affinity chromatography, a suitable tool that enabled us to eliminate the most abundant protein, the allophycocyanin. We also demonstrated that cell growth follows a light/dark cycle in A. platensis. This preliminary proteomic study has highlighted new characteristics of the Arthrospira platensis proteome in terms of diurnal regulation.

  1. Continuous cultivation of Arthrospira platensis using exhausted medium treated with granular activated carbon

    Science.gov (United States)

    Morocho-Jácome, Ana Lucía; Mascioli, Guilherme Favaro; Sato, Sunao; Carvalho, João Carlos Monteiro de

    2015-03-01

    Reusing culture medium of Arthrospira platensis is quite important in large scale production because its inappropriate disposal could exacerbate problems of environmental pollution. This study evaluates the suitability of using different quantities of exhausted Schlösser medium after continuous treatment using granular activated carbon (GAC) with a residence time (T) of 2 h for A. platensis growth in continuous cultivation. A tubular photobioreactor (PBR) and urea as cheap nitrogen source were used, taking as response variables kinetic parameters and biomass composition. The removal of both organic matter and pigment (OMR and PgR, respectively) was measured to evaluate the efficiency of the treatment process. This treatment process yielded high values of OMR (73.7 ± 0.1%) and PgR (52.4 ± 0.4%) using 75% treated medium, thereby A. platensis biomass with high protein content (42.0 ± 0.6%), 1568 ± 15 mg/L cell concentration under steady-state conditions and 941 mg/L d cell productivity. This alternative to simultaneous treatment with GAC for reuse of Schlösser medium in continuous cultivation could ensure no diminution in either cell productivity or protein content in A. platensis cultivation using tubular PBR with 65% reduction in medium culture costs.

  2. Production of phycobiliproteins by Arthrospira platensis under different lightconditions for application in food products

    Directory of Open Access Journals (Sweden)

    Roberta Ferreira Rizzo

    2015-06-01

    Full Text Available There has been an increase in investment in research on new sources of natural pigments for food application. Some cyanobacteria can change the structures responsible for light harvesting and cellular processes according to the wavelength and light intensity. This phenomenon has been described as complementary chromatic adaptation. The present study aimed to investigate the growth of Arthrospira platensis using different light qualities, irradiance, and wavelength by evaluating the production of biomass, proteins, and phycobiliproteins. The occurrence of the chromatic adaptation phenomenon in this cyanobacterium was also investigated. The microorganism used in this study, A. platensis, was grown in a Zarrouk medium under three irradiance levels, 50, 100, and 150 μmol fotons.m–2.s–1 with illumination provided by white and green fluorescent lamps. The condition of 150 µmol fotons.m–2.s–1 white light was the one that promoted the highest biomass production of A. platensis cultures (2115.24 mg.L–1. There was no difference in the production of total protein and total phycobiliproteins under the studied conditions. It is likely that the large supply of nitrogen in the Zarrouk medium was sufficient for cell growth and maintenance, and it supplied the production of accessory pigments composed of protein. Finally, there was no evidence of the complementary chromatic adaptation phenomenon in A. platensis cultivated under green light. Moreover, this condition did not increase phycocyanin production.

  3. Proteome-wide analysis and diel proteomic profiling of the cyanobacterium Arthrospira platensis PCC 8005.

    Science.gov (United States)

    Matallana-Surget, Sabine; Derock, Jérémy; Leroy, Baptiste; Badri, Hanène; Deschoenmaeker, Frédéric; Wattiez, Ruddy

    2014-01-01

    The filamentous cyanobacterium Arthrospira platensis has a long history of use as a food supply and it has been used by the European Space Agency in the MELiSSA project, an artificial microecosystem which supports life during long-term manned space missions. This study assesses progress in the field of cyanobacterial shotgun proteomics and light/dark diurnal cycles by focusing on Arthrospira platensis. Several fractionation workflows including gel-free and gel-based protein/peptide fractionation procedures were used and combined with LC-MS/MS analysis, enabling the overall identification of 1306 proteins, which represents 21% coverage of the theoretical proteome. A total of 30 proteins were found to be significantly differentially regulated under light/dark growth transition. Interestingly, most of the proteins showing differential abundance were related to photosynthesis, the Calvin cycle and translation processes. A novel aspect and major achievement of this work is the successful improvement of the cyanobacterial proteome coverage using a 3D LC-MS/MS approach, based on an immobilized metal affinity chromatography, a suitable tool that enabled us to eliminate the most abundant protein, the allophycocyanin. We also demonstrated that cell growth follows a light/dark cycle in A. platensis. This preliminary proteomic study has highlighted new characteristics of the Arthrospira platensis proteome in terms of diurnal regulation.

  4. Effets des extraits ou de la poudre de Spirulina platensis et Jatropha ...

    African Journals Online (AJOL)

    SARAH

    30 juin 2015 ... générale, les extraits ou la poudre de Spirulina platensis ont eu des ... 49.12 % and 48.29%, the number of fruits per plant by 43% and 43.45%, the fruit biomass by ..... Interactions of Jatropha curcas plantation with ecosystems. Proceeding of International. Conference on Energy and Environment, March.

  5. Primary Studies on Application of Choline Chloride in Culturing of Spirulina platensis%氯化胆碱在钝顶螺旋藻(Spirulina platensis)养殖中的应用初探

    Institute of Scientific and Technical Information of China (English)

    王大志; 单保党; 程兆弟; 洪华生

    1999-01-01

    Spirulina platensis was grown in Zarrouk′s meida with low NaHCO3 content (5~2 g/dm3), anf effects of growth hormone, choline chloride(CC) on growth, biomassa and biochemical composition were studied. The results showed that S. Platensis could grow very well at the condition of 4 g/dm3 NaHCO3 with 10.0 mg/dm3 CC ; biomass, protein and total carbohydrate contents were also increased to some extent. Low concentration of NaHCO3 (10.0 g/dm3 ) both have harmful effect on growth , biomass or protein content of S. platensis, but no effect on total carbohydrate content. Therefore CC can be used as an effective succedaneum of NaHCO3 in culturing of S.platensis and lead to decrease in the cultural cost.

  6. Ammonium nitrate and iron nutrition effects on some nitrogen assimilation enzymes and metabolites in Spirulina platensis.

    Science.gov (United States)

    Esen, Merve; Ozturk Urek, Raziye

    2015-01-01

    The effect of various concentrations of ammonium nitrate (5-60 mM), an economical nitrogen source, on the growth, nitrate-ammonium uptake rates, production of some pigments and metabolites, and some nitrogen assimilation enzymes such as nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) in Spirulina platensis (Gamont) Geitler was investigated. Ten millimolars of ammonium nitrate stimulated the growth, production of pigments and the other metabolites, and enzyme activities, whereas 30 and 60 mM ammonium nitrate caused inhibition. In the presence of 10 mM ammonium nitrate, different concentrations of iron were tried in the growth media of S. platensis. After achieving the best growth, levels of metabolite and pigment production, and enzyme activities in the presence of 10 mM ammonium nitrate as a nitrogen source, different iron concentrations (10-100 µM) were tried in the growth medium of S. platensis. The highest growth, pigment and metabolite levels, and enzyme activities were determined in the medium containing 50 µM iron and 10 mM ammonium nitrate. In this optimum condition, the highest dry biomass level, chlorophyll a, and pyruvate contents were obtained as 55.42 ± 3.8 mg mL(-1) , 93.114 ± 7.9 µg g(-1) , and 212.5 ± 18.7 µg g(-1) , respectively. The highest NR, NiR, GS, and GOGAT activities were 67.16 ± 5.1, 777.92 ± 52, 0.141 ± 0.01, and 44.45 ± 3.6, respectively. Additionally, 10 mM ammonium nitrate is an economical and efficient nitrogen source for nitrogen assimilation of S. platensis, and 50 µM iron is optimum for the growth of S. platensis. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

  7. Bioeffects of selenite on the growth of Spirulina platensis and its biotransformation.

    Science.gov (United States)

    Li, Zhi-Yong; Guo, Si-Yuan; Li, Lin

    2003-09-01

    The bioeffects of selenium on the growth of Spirulina platensis and the selenium distribution were investigated. S. platensis was batch cultured in Zarrouk medium containing increasing concentrations of sodium selenite. The biotransformation characteristic of selenium was analysed by the determination of the detailed selenium distribution forms. At 35 degrees C, 315.2 microEm(-2) x s(-1), sodium selenite concentrations below 400 mg x l(-1) were found to stimulate algal growth, especially in the range of 0.5-40 mg x l(-1). However, above 500 mg x l(-1) sodium selenite was toxic to this alga with the toxicity being related to the sulfite level in the medium. S. platensis was found to resist higher selenite by reducing toxic Se(IV) to nonsoluble Se(0). Selenium was accumulated efficiently in S. platensis during cultivation with accumulated selenium increasing with selenite concentration in the medium. It was demonstrated that inorganic selenite could be transformed into organic forms through binding with protein, lipids and polysaccharides and other cell components. The organic selenium accounted for 85.1% of the total accumulated selenium and was comprised of 25.2% water-soluble protein-bound, 10.6% lipids-bound and 2.1% polysaccharides-bound selenium. Among the organic fractions lipid possessed the strongest ability to accumulate Se (6.47 mg x kg(-1)). The 14.9% inorganic selenium in S. platensis was composed of Se(IV) (13.7%) and Se(VI) (1.2%).

  8. Spirulina platensis Enhances the Beneficial Effect of Exercise on Oxidative Stress and the Lipid Profile in Rats

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    Daiane Mazzola

    2015-12-01

    Full Text Available ABSTRACT This study aimed to evaluate the effect of Spirulina platensis and moderate exercise on oxidative stress and lipid profiles in the rats. Forty male Wistar rats were allocated to the following 10-week treatments, three times a week: exercise (E, 30 min swimming,S. platensis (SP, 26 mg/Kg; exercise andSpirulina (ES; and control (C. Outcomes were Thiobarbituric Acid Reactive Substances (TBARS in serum and brain, and cholesterol and triglycerides (TG in serum. Rats treated with exercise showed lower brain TBARS than the controls, mostly in association withS. platensis. In the groups E and ES, serum TBARS decreased after intervention. Compared with the controls, both E and ES prevented an increase in cholesterol and reduced triglycerides. Results demonstrated thatS. platensis enhanced the beneficial effect of exercise on oxidative stress and lipid profiles in rats, which might be a promising approach for treating metabolic syndrome in humans.

  9. Cultivo de Arthrospira platensis (Spirulina) en fotobiorreactor tubular doblemente curvado a condiciones ambientales en el sur del Perú

    National Research Council Canada - National Science Library

    Huarachi Olivera, Ronald Eleazar; Yapo Pari, Ursulo Avelino; Dueñas Gonza, Alex Paul; Condori Huamanga, Jose; Pacheco Salazar, David; Soto Flores, Joe

    2015-01-01

    ... el cultivo de la microalga Arthrospira platensis (Spirulina) en valores de productividad cultivado en fotobiorreactor tubular doblemente curvado a condiciones ambientales con el fin de aprovechar la alta radiación solar de la...

  10. Proteomic Analysis and qRT-PCR Verification of Temperature Response to Arthrospira (Spirulina) platensis: e83485

    National Research Council Canada - National Science Library

    Wang Huili; Zhao Xiaokai; Lin Meili; Randy A Dahlgren; Chen Wei; Zhou Jaiopeng; Xu Chengyang; Jin Chunlei; Xu Yi; Wang Xuedong; Ding Li; Bao Qiyu

    2013-01-01

      Arthrospira (Spirulina) platensis (ASP) is a representative filamentous, non-N2-fixing cyanobacterium that has great potential to enhance the food supply and possesses several valuable physiological features...

  11. In vitro evaluation of Spirulina platensis extract incorporated skin cream with its wound healing and antioxidant activities.

    Science.gov (United States)

    Gunes, Seda; Tamburaci, Sedef; Dalay, Meltem Conk; Deliloglu Gurhan, Ismet

    2017-12-01

    Algae have gained importance in cosmeceutical product development due to their beneficial effects on skin health and therapeutical value with bioactive compounds. Spirulina platensis Parachas (Phormidiaceae) is renowned as a potential source of high-value chemicals and recently used in skincare products. This study develops and evaluates skin creams incorporated with bioactive S. platensis extract. Spirulina platensis was cultivated, the aqueous crude extract was prepared and in vitro cytotoxicity of S. platensis extract in the range of 0.001-1% concentrations for 1, 3 and 7 d on HS2 keratinocyte cells was determined. Crude extracts were incorporated in skin cream formulation at 0.01% (w/w) concentration and in vitro wound healing and genotoxicity studies were performed. Immunohistochemical staining was performed to determine the collagen activity. 0.1% S. platensis extract exhibited higher proliferation activity compared with the control group with 198% of cell viability after 3 d. Skin cream including 1.125% S. platensis crude extract showed enhanced wound healing effect on HS2 keratinocyte cell line and the highest HS2 cell viability % was obtained with this concentration. The micronucleus (MN) assay results indicated that S. platensis extract incorporated creams had no genotoxic effect on human peripheral blood cells. Immunohistochemical analysis showed that collagen 1 immunoreactivity was improved by increased extract concentration and it was strongly positive in cells treated with 1.125% extract incorporated skin cream. The cell viability, wound healing activity and genotoxicity results showed that S. platensis incorporated skin cream could be of potential value in cosmeceutical and biomedical applications.

  12. iAK692: A genome-scale metabolic model of Spirulina platensis C1

    Science.gov (United States)

    2012-01-01

    Background Spirulina (Arthrospira) platensis is a well-known filamentous cyanobacterium used in the production of many industrial products, including high value compounds, healthy food supplements, animal feeds, pharmaceuticals and cosmetics, for example. It has been increasingly studied around the world for scientific purposes, especially for its genome, biology, physiology, and also for the analysis of its small-scale metabolic network. However, the overall description of the metabolic and biotechnological capabilities of S. platensis requires the development of a whole cellular metabolism model. Recently, the S. platensis C1 (Arthrospira sp. PCC9438) genome sequence has become available, allowing systems-level studies of this commercial cyanobacterium. Results In this work, we present the genome-scale metabolic network analysis of S. platensis C1, iAK692, its topological properties, and its metabolic capabilities and functions. The network was reconstructed from the S. platensis C1 annotated genomic sequence using Pathway Tools software to generate a preliminary network. Then, manual curation was performed based on a collective knowledge base and a combination of genomic, biochemical, and physiological information. The genome-scale metabolic model consists of 692 genes, 837 metabolites, and 875 reactions. We validated iAK692 by conducting fermentation experiments and simulating the model under autotrophic, heterotrophic, and mixotrophic growth conditions using COBRA toolbox. The model predictions under these growth conditions were consistent with the experimental results. The iAK692 model was further used to predict the unique active reactions and essential genes for each growth condition. Additionally, the metabolic states of iAK692 during autotrophic and mixotrophic growths were described by phenotypic phase plane (PhPP) analysis. Conclusions This study proposes the first genome-scale model of S. platensis C1, iAK692, which is a predictive metabolic platform

  13. iAK692: A genome-scale metabolic model of Spirulina platensis C1

    Directory of Open Access Journals (Sweden)

    Klanchui Amornpan

    2012-06-01

    Full Text Available Abstract Background Spirulina (Arthrospira platensis is a well-known filamentous cyanobacterium used in the production of many industrial products, including high value compounds, healthy food supplements, animal feeds, pharmaceuticals and cosmetics, for example. It has been increasingly studied around the world for scientific purposes, especially for its genome, biology, physiology, and also for the analysis of its small-scale metabolic network. However, the overall description of the metabolic and biotechnological capabilities of S. platensis requires the development of a whole cellular metabolism model. Recently, the S. platensis C1 (Arthrospira sp. PCC9438 genome sequence has become available, allowing systems-level studies of this commercial cyanobacterium. Results In this work, we present the genome-scale metabolic network analysis of S. platensis C1, iAK692, its topological properties, and its metabolic capabilities and functions. The network was reconstructed from the S. platensis C1 annotated genomic sequence using Pathway Tools software to generate a preliminary network. Then, manual curation was performed based on a collective knowledge base and a combination of genomic, biochemical, and physiological information. The genome-scale metabolic model consists of 692 genes, 837 metabolites, and 875 reactions. We validated iAK692 by conducting fermentation experiments and simulating the model under autotrophic, heterotrophic, and mixotrophic growth conditions using COBRA toolbox. The model predictions under these growth conditions were consistent with the experimental results. The iAK692 model was further used to predict the unique active reactions and essential genes for each growth condition. Additionally, the metabolic states of iAK692 during autotrophic and mixotrophic growths were described by phenotypic phase plane (PhPP analysis. Conclusions This study proposes the first genome-scale model of S. platensis C1, iAK692, which is a

  14. Growth and biopigment accumulation of cyanobacterium Spirulina platensis at different light intensities and temperature

    Science.gov (United States)

    Kumar, Manoj; Kulshreshtha, Jyoti; Singh, Gajendra Pal

    2011-01-01

    In order to find out optimum culture condition for algal growth, the effect of light irradiance and temperature on growth rate, biomass composition and pigment production of Spirulina platensis were studied in axenic batch cultures. Growth kinetics of cultures showed a wide range of temperature tolerance from 20 °C to 40 °C. Maximum growth rate, cell production with maximum accumulation of chlorophyll and phycobilliproteins were found at temperature 35 °C and 2,000 lux light intensity. But with further increase in temperature and light intensity, reduction in growth rate was observed. Carotenoid content was found maximum at 3,500 lux. Improvement in the carotenoid content with increase in light intensity is an adaptive mechanism of cyanobacterium S.platensis for photoprotection, could be a good basis for the exploitation of microalgae as a source of biopigments. PMID:24031731

  15. Isolation, purification and characterization of the hydrogen evolution promoting factor of hydrogenase of Spirulina platensis

    Science.gov (United States)

    Gu, Tian-Qing; Zhang, Hui-Miao; Sun, Shi-Hua

    1996-03-01

    A component (s-factor) with obvious promoting effect on hydrogen evolution of hydrogenase has been isolated and extracted from a cell-free preparation of Spirulina platensis. The effect of the s-factor in the reaction system is similar to that of Na2S2O4, but is coupled with light. The s-factor has the maximum absorption peak at 620 nm in the oxidized state, at 590 nm in the reduced state. The partially purified s-factor showed two bands by SDS-PAGE and is distinctly different from phycocyanin, which has no change of oxidized state and reduced state absorption spectra, and also has no promoting effect on hydrogenase of Spirulina platensis under the light.

  16. Nitrogen effects on proteins, chlorophylls and fatty acids during the growth of Arthrospira platensis.

    Science.gov (United States)

    Ayachi, Samah; El Abed, Amor; Dhifi, Wissal; Marzouk, Brahim

    2007-06-01

    Spirulina platensis (=Arthrospira platensis) is a tunisian strain which has been isolated for the first time in Oued Essed (Sousse, Sidi Bou Ali). Biomass evolution, proteins, chlorophylls and fatty acids composition of this alga were monitored by varying nitrogen concentrations in the culture medium. Nitrogen stress was provoked by adding sodium nitrate (NaNO3) in the culture medium with concentrations varying from 0 to 5 g/l. Results obtained showed that nitrogen depletion increased total proteins and total chlorophylls. The addition of NaNO3 (5g/l) led to an increase of total fatty acids amounts and modify fatty acids composition. Optimal quantities of palmitic, gamma -linolenic and oleic acids were obtained with NaNO3 free-cultures. Thus, the tunisian strain has valuable biological substances, worthy to determine the optimal conditions for its propagation.

  17. Cultivo mixotrófico da microalga Spirulina platensis em batelada alimentada Mixotrophic growth of Spirulina platensis in fed-batch mode

    Directory of Open Access Journals (Sweden)

    Adriana Muliterno

    2005-12-01

    Full Text Available A Spirulina platensis tem sido estudada devido a seu alto valor protéico, digestibilidade e por apresentar quantidades significativas de ácidos graxos poliinsaturados, vitaminas, fenólicos e ficocianina, podendo ser utilizada na alimentação humana. A utilização de nutrientes de baixo custo é um fator importante na produção da cianobactéria por possibilitar a redução de custos de processo. Objetivou-se com este trabalho estudar o cultivo mixotrófico da S. platensis por meio da adição de uma fonte orgânica de carbono (glicose em modo bateladaalimentada. Foi utilizado um Planejamento Fatorial Completo 2³ para o cultivo e as variáveis de estudo foram a concentração de glicose (0,5 gL-1 e 1,0 gL-1, a diluição do meio Zarrouk (50% e 75% e a iluminância (1800 lux e 3000 lux. A concentração celular máxima obtida foi de 5,38 gL-1 com uma velocidade específica máxima de crescimento de 0,0063 h-1, nas condições de 0,5 gL-1 de glicose, diluição do meio de 75% e iluminância de 3000 lux.The cyanobacterium Spirulina platensis has been studied due to its high content (~65% of highly digestible protein as well as significant amounts of polyunsaturated fatty acids, phenolics, vitamins, minerals and phycocyanin which could be useful in the human nutrition. The use of nutrients of low costs in the cyanobacterium growth could reduce the costs of production. We studied the fed-batch mixotrophic growth of the S. platensis in Zarrouk's medium with glucose (0.5 gL-1 and 1.0 gL-1 as carbon source and also investigated the effects of dilution (50% and 75%, with water and illumination (1,800 lux and 3,000 lux using a 2³ factorial design. The maximum celular concentration of 5.38 gL-1 and maximum specific growth rate of 0.0063 h-1 were obtained with a glucose concentration of 0.5 gL-1, 50% dilution and 1800 lux of illuminance.

  18. Effect of the spirulina platensis included in the main diet on the boar sperm quality

    OpenAIRE

    Kistanova E.; Marchev Y.; Nedeva R.; Kacheva D.; Shumkov K.; Georgiev B.; Shimkus A.

    2009-01-01

    Microalgae Spirulina platensis accumulates many chemical components which are suitable for all higher organisms as food and forage raw material. There are a lot of vitally important for the organisms minerals and macroelements such as iron, calcium, sodium, potassium, copper, magnesium, phosphorus, selenium, vitamins, carotin, nucleic acids, enzymes and other active substances. That should explain the value of Spirulina as a feed additive for the agricultural animals. In the present work the ...

  19. Optimization of medium components using orthogonal arrays for Linolenic acid production by Spirulina platensis

    Science.gov (United States)

    This work describes the medium optimization of '-Linolenic acid (GLA) production by Spirulina platensis using one-factor and orthogonal array design methods. In the one-factor experiments, NaHCO3 (9 mg L-1), NaNO3 (13.5 mg L-1) and MgSO4•7H2O (11.85 mg L-1) proved to be the best components for GLA p...

  20. Genomic structure of an economically important cyanobacterium, Arthrospira (Spirulina) platensis NIES-39.

    Science.gov (United States)

    Fujisawa, Takatomo; Narikawa, Rei; Okamoto, Shinobu; Ehira, Shigeki; Yoshimura, Hidehisa; Suzuki, Iwane; Masuda, Tatsuru; Mochimaru, Mari; Takaichi, Shinichi; Awai, Koichiro; Sekine, Mitsuo; Horikawa, Hiroshi; Yashiro, Isao; Omata, Seiha; Takarada, Hiromi; Katano, Yoko; Kosugi, Hiroki; Tanikawa, Satoshi; Ohmori, Kazuko; Sato, Naoki; Ikeuchi, Masahiko; Fujita, Nobuyuki; Ohmori, Masayuki

    2010-04-01

    A filamentous non-N(2)-fixing cyanobacterium, Arthrospira (Spirulina) platensis, is an important organism for industrial applications and as a food supply. Almost the complete genome of A. platensis NIES-39 was determined in this study. The genome structure of A. platensis is estimated to be a single, circular chromosome of 6.8 Mb, based on optical mapping. Annotation of this 6.7 Mb sequence yielded 6630 protein-coding genes as well as two sets of rRNA genes and 40 tRNA genes. Of the protein-coding genes, 78% are similar to those of other organisms; the remaining 22% are currently unknown. A total 612 kb of the genome comprise group II introns, insertion sequences and some repetitive elements. Group I introns are located in a protein-coding region. Abundant restriction-modification systems were determined. Unique features in the gene composition were noted, particularly in a large number of genes for adenylate cyclase and haemolysin-like Ca(2+)-binding proteins and in chemotaxis proteins. Filament-specific genes were highlighted by comparative genomic analysis.

  1. Wound healing potential of Spirulina platensis extracts on human dermal fibroblast cells

    Science.gov (United States)

    Syarina, Pauzi Nur Aimi; Karthivashan, Govindarajan; Abas, Faridah; Arulselvan, Palanisamy; Fakurazi, Sharida

    2015-01-01

    Blue-green alga (Spirulina platensis) is a well renowned nutri-supplement due to its high nutritional and medicinal properties. The aim of this study was to examine the wound healing efficiency of Spirulina platensis at various solvent extracts using in vitro scratch assay on human dermal fibroblast cells (HDF). Various gradient solvent extracts (50 μg/ml of methanolic, ethanolic and aqueous extracts) from Spirulina platensis were treated on HDF cells to acquire its wound healing properties through scratch assay and in this investigation we have used allantoin, as a positive control to compare efficacy among the phytoextracts. Interestingly, aqueous extract were found to stimulate proliferation and migration of HDF cells at given concentrations and enhanced closure rate of wound area within 24 hours after treatment. Methanolic and ethanolic extracts have shown proliferative effect, however these extracts did not aid in the migration and closure of wound area when compared to aqueous extract. Based on phytochemical profile of the plant extracts analyzed by LC-MS/MS, it was shown that compounds supposedly involved in accelerating wound healing are cinnamic acid, narigenin, kaempferol, temsirolimus, phosphatidylserine isomeric derivatives and sulphoquinovosyl diacylglycerol. Our findings concluded that blue-green algae may pose potential biomedical application to treat various chronic wounds especially in diabetes mellitus patients. PMID:27004048

  2. Wound healing potential of Spirulina platensis extracts on human dermal fibroblast cells.

    Science.gov (United States)

    Syarina, Pauzi Nur Aimi; Karthivashan, Govindarajan; Abas, Faridah; Arulselvan, Palanisamy; Fakurazi, Sharida

    2015-01-01

    Blue-green alga (Spirulina platensis) is a well renowned nutri-supplement due to its high nutritional and medicinal properties. The aim of this study was to examine the wound healing efficiency of Spirulina platensis at various solvent extracts using in vitro scratch assay on human dermal fibroblast cells (HDF). Various gradient solvent extracts (50 μg/ml of methanolic, ethanolic and aqueous extracts) from Spirulina platensis were treated on HDF cells to acquire its wound healing properties through scratch assay and in this investigation we have used allantoin, as a positive control to compare efficacy among the phytoextracts. Interestingly, aqueous extract were found to stimulate proliferation and migration of HDF cells at given concentrations and enhanced closure rate of wound area within 24 hours after treatment. Methanolic and ethanolic extracts have shown proliferative effect, however these extracts did not aid in the migration and closure of wound area when compared to aqueous extract. Based on phytochemical profile of the plant extracts analyzed by LC-MS/MS, it was shown that compounds supposedly involved in accelerating wound healing are cinnamic acid, narigenin, kaempferol, temsirolimus, phosphatidylserine isomeric derivatives and sulphoquinovosyl diacylglycerol. Our findings concluded that blue-green algae may pose potential biomedical application to treat various chronic wounds especially in diabetes mellitus patients.

  3. Biochemical composition and antioxidant activities of Arthrospira (Spirulina) platensis in response to gamma irradiation.

    Science.gov (United States)

    Shabana, Effat Fahmy; Gabr, Mahmoud Ali; Moussa, Helal Ragab; El-Shaer, Enas Ali; Ismaiel, Mostafa M S

    2017-01-01

    Arthrospira (Spirulina) platensis is a blue-green alga, rich with bioactive components and nutrients. To evaluate effect of gamma irradiation, A. platensis was exposed to different doses of 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5kGy. The data showed that the phenolic and proline contents significantly increased with the increase of gamma irradiation doses up to 2.0kGy, above which a reduction was observed. The soluble proteins and malondialdehyde (MDA) contents were stimulated by all tested irradiation doses. Furthermore, the vitamins (A, K and B group) and mineral contents (N, P, Na, K, Ca, Mg and Fe) were stimulated by the irradiation doses compared with the control. The activities of some N-assimilating and antioxidant enzymes were significantly increased with the irradiation doses up to 2.0kGy. This study suggests the possible use of gamma irradiation as a stimulatory agent to raise the nutritive value and antioxidant activity of A. platensis.

  4. Spirulina platensis feeding inhibited the anemia- and leucopenia-induced lead and cadmium in rats.

    Science.gov (United States)

    Simsek, Nejdet; Karadeniz, Ali; Kalkan, Yildiray; Keles, Osman N; Unal, Bünyami

    2009-05-30

    In the present investigation, the effect of Spirulina platensis (Sp) was undertaken on rats fed with lead and cadmium including diet by using physiological, enzymehistochemical and stereological methods. For this aim, 50 rats were equally divided into five groups as control (C), lead (Pb), Spirulina+lead (Sp+Pb), cadmium (Cd), and Spirulina+cadmium (Sp+Cd). Red blood cell (RBC) and white blood cell (WBC) counts, packed cell volume (PCV), and haemoglobine (Hb) concentrations were determined by haemocytometric methods in blood samples collected on 30th day. Population of T lymphocyte was counted by the alpha-naphthyl acetate esterase (ANAE) staining method, and reticulocytes were counted by stereological method. The counts of RBC, WBC, and ANAE positive T lymphocyte, and the values of Hb, PCV, and MCHC were decreased in the Pb and Cd groups compared to control group. Also, the number of reticulocytes (polychromatofilic erythrocyte) increased in the Pb groups, whereas it decreased in the Cd group. On the other hand, these values were ceased by S. platensis in the treated groups. These results suggest that S. platensis supplementation may be useful in adjuvant treatment of leukemia and anemia caused by lead and cadmium toxication.

  5. Spirulina platensis feeding inhibited the anemia- and leucopenia-induced lead and cadmium in rats

    Energy Technology Data Exchange (ETDEWEB)

    Simsek, Nejdet [University of Atatuerk, Faculty of Veterinary Medicine, Department of Histology and Embryology, 25700 Erzurum (Turkey); Karadeniz, Ali, E-mail: karadenizali@gmail.com [University of Atatuerk, Faculty of Veterinary Medicine, Department of Physiology, 25700 Erzurum (Turkey); Kalkan, Yildiray; Keles, Osman N.; Unal, Buenyami [University of Atatuerk, Faculty of Medicine, Department of Histology and Embryology, 25240 Erzurum (Turkey)

    2009-05-30

    In the present investigation, the effect of Spirulina platensis (Sp) was undertaken on rats fed with lead and cadmium including diet by using physiological, enzymehistochemical and stereological methods. For this aim, 50 rats were equally divided into five groups as control (C), lead (Pb), Spirulina + lead (Sp + Pb), cadmium (Cd), and Spirulina + cadmium (Sp + Cd). Red blood cell (RBC) and white blood cell (WBC) counts, packed cell volume (PCV), and haemoglobine (Hb) concentrations were determined by haemocytometric methods in blood samples collected on 30th day. Population of T lymphocyte was counted by the {alpha}-naphthyl acetate esterase (ANAE) staining method, and reticulocytes were counted by stereological method. The counts of RBC, WBC, and ANAE positive T lymphocyte, and the values of Hb, PCV, and MCHC were decreased in the Pb and Cd groups compared to control group. Also, the number of reticulocytes (polychromatofilic erythrocyte) increased in the Pb groups, whereas it decreased in the Cd group. On the other hand, these values were ceased by S. platensis in the treated groups. These results suggest that S. platensis supplementation may be useful in adjuvant treatment of leukemia and anemia caused by lead and cadmium toxication.

  6. Peningkatan Respons Imun Non Spesifik Ikan Gurame Pascapemberian Ekstrak Air Panas Mikroalga Spirulina platensis (ENHANCEMENT OF NON-SPECIFIC IMMUNE RESPONSE OF OSPHRONEMUS GOURAMY AFTER GIVING OF HOT WATER EXTRACT SPIRULINA PLATENSIS

    Directory of Open Access Journals (Sweden)

    Woro Hastuti Satyantini

    2016-11-01

    Full Text Available Hot water extract of Spirulina platensis which is contain of lipopolysaccharide can be used as animmunostimulant. This study aimed to determine the effect of hot water extract of S. platensis throughinjection on the non-specific immune response of Osphronemusgouramy. The treatment was given throughintraperitoneal injection of hot water extract of S. platensis with doses of 1%, 10%, 20% and PBS, PhosphateBuffer Saline (control 0.1 ml/fish. Fish reared in the aquarium (67 l volune with density 12 fishes/aquarium with average weight of 7.5 – 8.5 g/fish. Blood samples of fish taken from the caudal vein on day0 (before administration of the extract, 3 and 5 days after administration of the extract for the measurementof total leucocytes, differential leucocytes and phagocytic activity. Results showed an increased in totalleucocytes, phagocytic activity, monocytes and neutrophils of fish that given hot water extract of S. platensis.The addition of hot water extract of S. platensis at 1% through injection gave total leucocytes, phagocyticactivity, monocytes and neutrophils on days 3 were 543.73 x 103sel/mm3,69.30%, 34.33% and 14%respectively higher and significantly different to control.

  7. A Multivariate Approach to Evaluate Biomass Production, Biochemical Composition and Stress Compounds of Spirulina platensis Cultivated in Wastewater.

    Science.gov (United States)

    Çelekli, Abuzer; Topyürek, Ali; Markou, Giorgos; Bozkurt, Hüseyin

    2016-10-01

    The study was performed to investigate the effects of using cow effluent for the cultivation of Spirulina platensis on its biomass production and cell physiology. S. platensis was cultivated in three different cow effluents (CE) used as cultivation medium during 15 days. CE was prepared using dry cow manures, and it was further modified with supplement of NaNO3 (CEN) and NaNO3 + NaCl (CENS). High nitrate value stimulated chlorophyll-a and total protein content of the cyanobacterium and also biomass production in standards medium (SM) and CEN media. Total carbohydrate content of S. platensis grown in CE media was found to be higher (p biomass and biochemical compounds by the cyanobacterium grown on the CE and SM media were evaluated by using multivariate approach. Conductivity, oxidation reduction potential (ORP), salinity, pH, and TDS played important role (p biomass production, filament length, and proline. Canonical correspondence analysis proposed that biochemical compounds of S. platensis were not only affected by salinity and nutrition of media but also by pH and ORP. The present study indicated that CEN as a low cost model medium had high potential for the production of biomass by S. platensis with high protein content.

  8. Effect of intermittent light on oxygen production of Spirulina platensis; Supirurina no sansohassei ni oyobosu shukiko no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Ohira, Y.; Abe, T.; Kuga, Y.; Ando, K. [Muroran Institute of Technology, Hokkaido (Japan). Dept. of Applied Chemistry

    2000-05-10

    S. platensis media were irradiated with intermittent light interrupted by a slit in a rotating disk. The effects of the light periodicity, irradiation time, and dark time during a cycle on the oxygen production rate of S. platensis are experimentally discussed. The following oxygen production ratio was used as the index to compare the oxygen production rate between the intermittent light and the continuous light. (Oxygen production ratio)=(Oxygen volume produced by intermittent light)/(Opening ratio of the disk)(Oxygen volume produced by continuous light). When S. platensis media were irradiated with the intermittent light having a periodicity of 0.0044-0.60 s{sup -1}, the oxygen production ratio increased with an increased with an increase in light periodicity. The value of the oxygen production ratio is greater than one when the irradiation time during a cycle is shorter than 1 s. Under these conditions, the oxygen production ratio increases with increasing dark time. the effect of the intermittent light on the oxygen production rate of S. platensis was found to be qualitatively described by the simple model which combined the oxygen production rate of S. platensis and the respiration rate. (author)

  9. Bioremediation of surface water co-contaminated with zinc (II) and linear alkylbenzene sulfonates by Spirulina platensis

    Science.gov (United States)

    Meng, Huijuan; Xia, Yunfeng; Chen, Hong

    Potential remediation of surface water contaminated with linear alkylbenzene sulfonates (LAS) and zinc (Zn (II)) by sorption on Spirulina platensis was studied using batch techniques. Results show that LAS can be biodegraded by Spirulina platensis, and its biodegradation rate after 5 days was 87%, 80%, and 70.5% when its initial concentration was 0.5, 1, and 2 mg/L, respectively. The maximum Zn (II) uptake capacity of Spirulina platensis was found to be 30.96 mg/g. LAS may enhance the maximum Zn (II) uptake capacity of Spirulina platensis, which can be attributed to an increase in bioavailability due to the presence of LAS. The biodegradation rates of LAS by Spirulina platensis increased with Zn (II) and reached the maximum when Zn (II) was 4 mg/L. The joint toxicity test showed that the combined effect of LAS and Zn (II) was Synergistic. LAS can enhance the biosorption of Zn (II), and reciprocally, Zn (II) can enhance LAS biodegradation.

  10. Anti-cancer effects of blue-green alga Spirulina platensis, a natural source of bilirubin-like tetrapyrrolic compounds.

    Science.gov (United States)

    Koníčková, Renata; Vaňková, Kateřina; Vaníková, Jana; Váňová, Kateřina; Muchová, Lucie; Subhanová, Iva; Zadinová, Marie; Zelenka, Jaroslav; Dvořák, Aleš; Kolář, Michal; Strnad, Hynek; Rimpelová, Silvie; Ruml, Tomáš; J Wong, Ronald; Vítek, Libor

    2014-01-01

    Spirulina platensis is a blue-green alga used as a dietary supplement because of its hypocholesterolemic properties. Among other bioactive substances, it is also rich in tetrapyrrolic compounds closely related to bilirubin molecule, a potent antioxidant and anti-proliferative agent. The aim of our study was to evaluate possible anticancer effects of S. platensis and S. platensis-derived tetrapyrroles using an experimental model of pancreatic cancer. The anti-proliferative effects of S. platensis and its tetrapyrrolic components [phycocyanobilin (PCB) and chlorophyllin, a surrogate molecule for chlorophyll A] were tested on several human pancreatic cancer cell lines and xenotransplanted nude mice. The effects of experimental therapeutics on mitochondrial reactive oxygen species (ROS) production and glutathione redox status were also evaluated. Compared to untreated cells, experimental therapeutics significantly decreased proliferation of human pancreatic cancer cell lines in vitro in a dose-dependent manner (from 0.16 g•L-1 [S. platensis], 60 μM [PCB], and 125 μM [chlorophyllin], palga. Furthermore, it seems that dietary supplementation with this alga might enhance systemic pool of tetrapyrroles, known to be higher in subjects with Gilbert syndrome.

  11. Enhanced annealing stability and perpendicular magnetic anisotropy in perpendicular magnetic tunnel junctions using W layer

    Science.gov (United States)

    Chatterjee, Jyotirmoy; Sousa, Ricardo C.; Perrissin, Nicolas; Auffret, Stéphane; Ducruet, Clarisse; Dieny, Bernard

    2017-05-01

    The magnetic properties of the perpendicular storage electrode (buffer/MgO/FeCoB/Cap) were studied as a function of annealing temperature by replacing Ta with W and W/Ta cap layers with variable thicknesses. W in the cap boosts up the annealing stability and increases the effective perpendicular anisotropy by 30% compared to the Ta cap. Correspondingly, an increase in the FeCoB critical thickness characterizing the transition from perpendicular to in-plane anisotropy was observed. Thicker W layer in the W(t)/Ta 1 nm cap layer makes the storage electrode highly robust against annealing up to 570 °C. The stiffening of the overall stack resulting from the W insertion due to its very high melting temperature seems to be the key mechanism behind the extremely high thermal robustness. The Gilbert damping constant of FeCoB with the W/Ta cap was found to be lower when compared with the Ta cap and stable with annealing. The evolution of the magnetic properties of bottom pinned perpendicular magnetic tunnel junctions (p-MTJ) stack with the W2/Ta1 nm cap layer shows back-end-of-line compatibility with increasing tunnel magnetoresistance up to the annealing temperature of 425 °C. The pMTJ thermal budget is limited by the synthetic antiferromagnetic hard layer which is stable up to 425 °C annealing temperature while the storage layer is stable up to 455 °C.

  12. Fatigue In Tension Perpendicular to the Grain

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Uhre; Hoffmeyer, Preben;

    2004-01-01

    mechanism and a mechanism connected to damage introduced in the loading sequences. The purpose of the present study is to disentangle the effect of duration of load from the effect of load oscillation in fatigue in tension perpendicular to the grain. Fatigue experiments are made on small specimens...... and on dowel type joints with slotted in steel plates. In series of ten, the small specimens are taken to fatigue failure in uniform tension at square wave shaped load cycles at 0.01 Hz and 0.1 Hz. In arder to test the predictive validity of the result from the small tension specimens, fatigue experiments......Traditionally fatigue resistance is quantified as number of cycles to failure at a given stress level. A previous study by the authors showed that fatigue in compression parallel to the grain is governed partly by duration of load and partly by an effect of loading, i.e. a combination of a creep...

  13. Fatigue in tension perpendicular to the grain

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben;

    1999-01-01

    mechanism and a mechanism connected to damage introduce in the loading sequences. The purpose of the present study is to disentangle the effect of duration of load from the effect of load oscillation in fatigue in tension perpendicular to the grain. Fatigue experiments are made on small specimens...... and on dowel type joints with slotted in steel plates. In series of ten, the small specimens are taken to fatigue failure in uniform tension at square wave shaped load cycles at 0.01 Hz and 0.1 Hz. In order to test the predictive validity of the result from the small tension specimens, fatigue experiments......Traditinally fatigue resistance is quantified as number of cycles to failure at a given stress level. A previous study by the authors showed that fatigue in compression parallel to the grain is governed partly by duration of load and partly by an effect of loading, i.e. a combination of a creep...

  14. Assessment of the antifungal activity of Spirulina platensis phenolic extract against Aspergillus flavus Avaliação da atividade antifúngica de extrato fenólico de Spirulina platensis contra Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Michele Moraes de Souza

    2011-12-01

    Full Text Available The production of safe food has stimulated the search for natural substances that possess antifungal activity. The indirect methods of estimating fungal biomass are based on the measurement of glucosamine, ergosterol and protein - typical compounds produced during the development of biomass. The aim of the study was to assess the effect of the phenolic extract from Spirulina platensis on the production of structural compounds in Aspergillus flavus, in order to identify its action on fungal inhibition. The Spirulina platensis methanolic extracts presented 1.15 mg phenolic compound/g Spirulina platensis, which showed an antifungal effect against Aspergillus flavus, inhibiting the glucosamine production up to 56%. Therefore, it may be employed as natural defense when food protection is necessary.A produção de alimentos seguros tem estimulado a busca por substâncias naturais que possuem atividade antifúngica. Os métodos indiretos de estimativa de biomassa fúngica são baseados na medição de glucosamina, ergosterol e proteína - compostos típicos produzidos durante o desenvolvimento da biomassa. Neste estudo, objetivou-se avaliar o efeito do extrato fenólico de Spirulina platensis na produção de componentes estruturais em Aspergillus flavus, a fim de identificar seu mecanismo de ação dos fenóis na inibição fúngica. O extrato metanólico de Spirulina platensis apresentou 1,15 mg de compostos fenólicos/g Spirulina platensis, apresentando um efeito antifúngico contra Aspergillus flavus, inibindo a produção de glucosamina em até 56%. Portanto, pode ser empregado como antifúngico natural quando for necessária a proteção de alimentos.

  15. Chromium (VI) biosorption and removal of chemical oxygen demand by Spirulina platensis from wastewater-supplemented culture medium.

    Science.gov (United States)

    Magro, Clinei D; Deon, Maitê C; De Rossi, Andreia; Reinehr, Christian O; Hemkemeier, Marcelo; Colla, Luciane M

    2012-01-01

    The inappropriate discharge of wastewater containing high concentrations of toxic metals is a serious threat to the environment. Given that the microalga Spirulina platensis has demonstrated a capacity for chromium VI (Cr (VI) biosorption, we assessed the ideal concentration of chromium-containing wastewater required for maximum removal of Cr (VI) and chemical oxygen demand (COD) from the environment by using this microalga. The Paracas and Leb-52 strains of S. platensis, with initial wastewater concentrations of 0%, 12.5%, 25%, and 50%, were cultured in Zarrouk medium diluted to 50% under controlled air, temperature, and lighting conditions. The cultures were maintained for 28 days, and pH, biomass growth, COD, and Cr (VI) were assessed. The wastewater concentration influenced microalgal growth, especially at high concentrations. Removal of 82.19% COD and 60.92% Cr (VI) was obtained, but the COD removal was greater than the Cr (VI) removal in both strains of S. platensis.

  16. Effects of solar ultraviolet radiation on the photochemical efficiency, photosynthetic pigments and biomass production of Spirulina platensis

    Institute of Scientific and Technical Information of China (English)

    WU Hongyan; GAO Kunshan; Teruo WATANABE

    2005-01-01

    Effects of solar ultraviolet radiation (UVR) on Spirulina platensis were studied by investigating its photochemical efficiency, photosynthetic pigments and biomass production while exposed to full spectrum solar radiation or depleted of UVR for understanding how and to what extent UVR influences its photosynthetic physiology and production. It was found that UVR brought about an extra inhibition of photochemical efficiency by 26 %-30 %. The greatest inhibition of photochemical efficiency in S. platensis was observed at noontime, and then recovered to some extent in late afternoon no matter which treatment they were exposed to. The contents of chlorophyll a, phycocyanin and carotenoids increased during initial stage of the exposure, but decreased with elongated exposure. UVR decreased the biomass yield by about 6 %. It indicated that filtering out UVR of solar radiation would raise the productivity of S. platensis,which is an important factor that should be considered in the production.

  17. The occurrence and biosynthesis of gamma-linolenic acid in a blue-green alga,Spirulina platensis.

    Science.gov (United States)

    Nichols, B W; Wood, B J

    1968-01-01

    The acyl-lipid and fatty acid composition of six blue-green algae, namely,Spirulina platensis, Myxosarcina chroococcoides, Chlorogloea fritschii, Anabaena cylindrica, Anabaena flos-aquae, and Mastigocladus laminosus is reported.All contain major proportions of mono-and digalactosyl diglyceride, sulfoquinovosyl diglyceride, and phosphatidyl glycerol, but none possess lecithin, phophatidyl ethanolamine, or phosphatidyl inositol. Trans-3-hexadecenoic acid was absent from all extracts.The analyses provide further evidence that there is no general chemical or physical requirement for any specific fatty acid in photosynthesis. S. platensis is unique among photoautotrophic organisms so far studied, containing major quantities of gamma-linolenic acid (6,9,12-octadecatrienoic acid). This acid is synthesized by the alga by direct desaturation of linoleic acid and is primarily located in the mono- and digalactosyl diglyceride fractions.The possible phylogenetic relationship betweenS. platensis and other plant forms is discussed.

  18. Perpendicular magnetic recording-Its development and realization

    Energy Technology Data Exchange (ETDEWEB)

    Iwasaki, Shun-ichi, E-mail: iwasaki@tohtech.ac.jp [Tohoku Institute of Technology, 35-1 Yagiyamakasumi-cho, Taihaku-ku, Sendai 982-8577 (Japan)

    2012-02-15

    Development of perpendicular magnetic recording is summarized along with learning from the research study. The early stage of perpendicular recording was conducted with the research philosophy of complementarity between perpendicular and horizontal recordings. Although present production of the perpendicular recording HDDs exceeds 600 million per year, development of perpendicular recording experienced the valley of death in the 1990s. The difficult period was overcome by the collaboration system of industrial and academic communities. The research on perpendicular recording brought about development of new research model as well as the historical view of the development of technology and innovation. The huge influence of perpendicular recording on society also taught us the relationship between science and technology with culture and civilization. - Research Highlights: > Discovery of circular magnetization led to idea of perpendicular recording. > SPT head and Co-Cr media were realized for practical perpendicular recording. > The complementarity between perpendicular and in-plane recording helped progress. > Death valley of research has been overcome by cooperation with potent companies. > Present mass production of HDDs is making a new civilization of the society.

  19. BISCOITOS DE CHOCOLATE ENRIQUECIDOS COM Spirulina platensis: CARACTERÍSTICAS FÍSICOQUÍMICAS, SENSORIAIS E DIGESTIBILIDADE

    Directory of Open Access Journals (Sweden)

    M. G. MORAIS

    2009-01-01

    Full Text Available

    As microalgas, como Spirulina, podem ser fonte de proteínas para alimentação humana, com a possibilidade de obter outros produtos como biopigmentos, vitaminas e lipídios. A biomassa obtida pode ser introduzida diretamente na dieta podendo auxiliar em casos de desnutrição. O objetivo deste trabalho foi avaliar as características físico-química, sensorial e digestibilidade de biscoitos de chocolate enriquecidos com a microalga Spirulina platensis. Foram elaborados quatro biscoitos de chocolate: controle (sem Spirulina e biscoitos contendo 1,0; 3,0 e 5,0% de Spirulina platensis. O biscoito com adição de 5,0% de Spirulina platensis apresentou o conteúdo protéico 7,7% maior que o controle. Os biscoitos com adição de 1,0% de S. platensis apresentaram maior digestibilidade (86,9% que os demais. Volume específico, espessura e fator de expansão não foram alterados pela adição de Spirulina. Não houve diferença significativa entre o biscoito controle e os biscoitos com adição de 5,0% nos atributos cor, crocância, mastigabilidade e maciez. Na avaliação questionamento de intenção de compra, comparando os biscoitos com adição de S. platensis, a amostra com maior aceitação pelos julgadores foi com 1,0% de S. platensis.

  20. Selenium uptake and assessment of the biochemical changes in Arthrospira (Spirulina) platensis biomass during the synthesis of selenium nanoparticles.

    Science.gov (United States)

    Zinicovscaia, I; Chiriac, T; Cepoi, L; Rudi, L; Culicov, O; Frontasyeva, M; Rudic, V

    2017-01-01

    The process of selenium uptake by biomass of the cyanobacterium Arthrospira (Spirulina) platensis was investigated by neutron activation analysis at different selenium concentrations in solution and at different contact times. Experimental data showed good fit with the Freundlich adsorption isotherm model, with a regression coefficient value of 0.99. In terms of absorption dependence on time, the maximal selenium content was adsorbed in the first 5 min of interaction without significant further changes. It was also found that A. platensis biomass forms spherical selenium nanoparticles. Biochemical analysis was used to assess the changes in the main components of spirulina biomass (proteins, lipids, carbohydrates, and phycobilin) during nanoparticle formation.

  1. Dynamics of gonadal development of Aegla platensis Schmitt (Decapoda, Anomura, Aeglidae Dinâmica do desenvolvimento gonadal de Aegla platensis Schmitt (Decapoda, Anomura, Aeglidae

    Directory of Open Access Journals (Sweden)

    Carolina C. Sokolowicz

    2006-12-01

    Full Text Available One way to estimate gonadal development through the reproductive cycle is to observe the growth of the gonads related to the organs used to store energy. The aim of this study was to follow the gonadosomatic and hepatosomatic indexes during annual cycle of Aegla platensis Schmitt, 1942. Adult animals were collected in Taquara, Rio Grande do Sul, Brazil (29°46'S, 50°53'W. Males and females were initially weighed and dissected and had their gonads and hepatopancreas (HP removed and weighed in order to estimate the Gonadosomatic (GI and hepatosomatic (HI indexes. In females, the indexes were also compared to the degree of development of the ovaries. In males the GI showed a peak of gonadal development in the autumn (p Uma maneira de estimar o desenvolvimento gonadal ao longo do ciclo reprodutivo é observar o crescimento das gônadas em relação aos órgãos utilizados para o estoque de energia. O objetivo desse estudo foi acompanhar os índices gonadossomático e hepatossomático durante o ciclo reprodutivo de Aegla platensis Schmitt, 1942. Animais adultos foram coletados em Taquara, Rio Grande do Sul, Brasil (29°46'S, 50°53'W. Machos e fêmeas foram pesados e dissecados, gônadas e hepatopâncreas (HP foram retirados e pesados para obtenção dos índices gonadossomático (IG e hepatossomático (IH. Nas fêmeas, os índices também foram comparados com o grau de desenvolvimento dos ovários. Nos machos o IG mostrou um pico de desenvolvimento gonadal no outono (p < 0,05, quando os valores do IH diminuíram (p < 0,05. Fêmeas mostraram um aumento do IG no final do verão e início do outono (p < 0,05 e os valores do IG aumentaram à medida que o ovário tornava-se maduro. Em A. platensis, tanto nos machos como nas fêmeas, os valores do IH nunca mostraram valores mais baixos que o IG, o que pode indicar que esses aeglídeos apresentam um padrão de utilização de energia diferente dos outros decápodos, onde à medida que o desenvolvimento

  2. Influence of Spirulina platensis powder on the microflora of yoghurt and acidophilus milk

    Directory of Open Access Journals (Sweden)

    Metin Guldas

    2010-12-01

    Full Text Available The main purpose of this research was to monitor the influence of the powdered Cyanobacterium Spirulina platensis addition to plain yoghurt and the yoghurt containing Lactobacillus acidophiluson survival of the microbiota during the refrigerated storage. The cell viability of yoghurt starter cultures (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus and Lactobacillus acidophilus under refrigeration conditions in yoghurts prepared with (0.5 or 1.0 (w/w % and without the addition of Spirulina powder was investigated. The yoghurts were prepared under hygienic laboratory conditions and their pH and acidity were controlled during the process. The samples of yoghurts were stored at 4 °C and investigated on days 1, 5, 10, 15, 20, 25 and 30. Viable counts of the lactic acid bacteria were above 6 cfu g-1of all “spirulina powder” added samples whereas control yoghurt samples contained lower lactic acid bacteria count at the end of the storage period. Addition of 1 % Spirulina platensis powder into the yoghurts did not cause significant differences on the viable lactic acid bacteria (p≤0.05. The results showed the positive effect of S. platensis powder on the survival of the lactic acid bacteria during storage of yoghurt (P≤0.05. The sensory analysis was also performed for the yoghurt samples. Sensory scores of 0.5 % spirulina powder added yoghurt samples were better than 1 % spirulina powder added ones. It was determined that spirulina powder added yoghurt is a good medium of lactic acid bacteria during the 30 days of refrigerated storage.

  3. Physiological and transcriptional responses to high temperature in Arthrospira (Spirulina) platensis C1.

    Science.gov (United States)

    Panyakampol, Jaruta; Cheevadhanarak, Supapon; Sutheeworapong, Sawannee; Chaijaruwanich, Jeerayut; Senachak, Jittisak; Siangdung, Wipawan; Jeamton, Wattana; Tanticharoen, Morakot; Paithoonrangsarid, Kalyanee

    2015-03-01

    Arthrospira (Spirulina) platensis is a well-known commercial cyanobacterium that is used as a food and in feed supplements. In this study, we examined the physiological changes and whole-genome expression in A. platensis C1 exposed to high temperature. We found that photosynthetic activity was significantly decreased after the temperature was shifted from 35°C to 42°C for 2 h. A reduction in biomass production and protein content, concomitant with the accumulation of carbohydrate content, was observed after prolonged exposure to high temperatures for 24 h. Moreover, the results of the expression profiling in response to high temperature at the designated time points (8 h) revealed two distinct phases of the responses. The first was the immediate response phase, in which the transcript levels of genes involved in different mechanisms, including genes for heat shock proteins; genes involved in signal transduction and carbon and nitrogen metabolism; and genes encoding inorganic ion transporters for magnesium, nitrite and nitrate, were either transiently induced or repressed by the high temperature. In the second phase, the long-term response phase, both the induction and repression of the expression of genes with important roles in translation and photosynthesis were observed. Taken together, the results of our physiological and transcriptional studies suggest that dynamic changes in the transcriptional profiles of these thermal-responsive genes might play a role in maintaining cell homeostasis under high temperatures, as reflected in the growth and biochemical composition, particularly the protein and carbohydrate content, of A. platensis C1.

  4. C-phycocyanin extraction assisted by pulsed electric field from Artrosphira platensis.

    Science.gov (United States)

    Martínez, Juan Manuel; Luengo, Elisa; Saldaña, Guillermo; Álvarez, Ignacio; Raso, Javier

    2017-09-01

    This paper assesses the application of pulsed electric fields (PEF) to the fresh biomass of Artrhospira platensis in order to enhance the extraction of C-phycocyanin into aqueous media. Electroporation of A. platensis depended on both electric field strength and treatment duration. The minimum electric field intensity for detecting C-phycocyanin in the extraction medium was 15kV/cm after the application of a treatment time 150μs (50 pulses of 3μs). However higher electric field strength were required when shorter treatment times were applied. Response surface methodology was used in order to investigate the influence of electric field strength (15-25kV/cm), treatment time (60-150μs), and temperature of application of PEF (10-40°C) on C-phycocyanin extraction yield (PEY). The increment of the temperature PEF treatment reduced the electric field strength and the treatment time required to obtain a given PEY and, consequently decreased the total specific energy delivered by the treatment. For example, the increment of temperature from 10°C to 40°C permitted to reduce the electric field strength required to extract 100mg/g dw of C-phycocyanin from 25 to 18kV/cm, and the specific energy input from 106.7 to 67.5kJ/Kg. Results obtained in this investigation demonstrated PEF's potential for selectively extraction C-phycocyanin from fresh A. platensis biomass. The purity of the C-phycocyanin extract obtained from the electroporated cells was higher than that obtained using other techniques based on the cell complete destruction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Growth response of Spirulina platensis PCC9108 to elevated CO2 levels and flue gas

    Directory of Open Access Journals (Sweden)

    Seyedmahdi Hoseini

    2014-01-01

    Full Text Available Introduction: Because their ability to capture CO2, photosynthetical microorganisms have some advantages to CO2 mitigation from high CO2 streams such as flue gases and they can use CO2 as carbon source. Recently, experts have made efforts to exploit microorganisms intended for recovering CO2 from power plants. Materials and methods: To achieve this purpose, we studied the growth response of the cyanobacterium Spirulina platensis PCC9108 under different concentrations of carbon dioxide (ranging from 0.036% to 10% and flue gas in a bench-scale system. Preparation of different concentrations of CO2 and injection into Erlenmeyer flasks was performed by a system including air compressor, CO2 capsule, pressure gauge and flow meter. Results: The main goal of studying this paper is a survey of organism's potential to grow by generated CO2 from flue gas of power plant. It already had the potential and highest biomass production recorded at 8% CO2 (v/v. Also we proved that S.platensis PCC9108 can be grown under flue gas, although biomass production decreased fairly. Total lipid content of algae interestingly enhanced with elevated CO2 levels from ambient air to 4% and 6% which ranged from 14.5 to 15.8 and 16 dry weight (wt. % respectively. In contrast, total protein content illustrated no difference between all treatment and its value was about 46 wt.%. Discussion and conclusion: The results of present study suggested that understudied S.platensis PCC9108 is appropriate for mitigating CO2 because of its carbon fixation ability. Also due to its high protein content, this cyanobacterium is a good candidate to produce SCP (single cell protein.

  6. Spirulina platensis: process optimization to obtain biomass Spirulina platensis: otimização de processo para a obtenção de biomassa

    Directory of Open Access Journals (Sweden)

    Iracema de Oliveira Moraes

    2013-02-01

    Full Text Available Spirulina platensis is a photoautotrophic mesophilic cyanobacterium. Its main sources of nutrients are nitrate, urea, and ammonium salts. Spirulina cultivation requires temperature, light intensity, and nutrient content control. This microalgae has been studied and used commercially due to its therapeutic and antioxidant potential. In addition, several studies have reported its ability to use CO2, its immune activity, and use as an adjuvant nutritive factor in the treatment of obesity. The objective of this study is the production of biomass of S. platensis using different rates of stirring, nitrogen source, amount of micronutrients, and luminosity. A 2(4 experimental design with the following factors: stirring (120 and 140 RPM, amount of nitrogen (1.5 and 2.5 g/L, amount of micronutrients (0,25 and 0,75 mL/L (11 and 15 W, and luminosity was used. Fermentation was performed in a 500 mL conical flask with 250 mL of culture medium and 10% inoculum in an incubator with controlled stirring and luminosity. Fermentation was monitored using a spectrophotometer (560 nm, and each fermentation lasted 15 days. Of the parameters studied, luminosity is the one with the highest significance, followed by the amount of nitrogen and the interaction between stirring and micronutrients. Maximum production of biomass for 15 days was 2.70 g/L under the following conditions: luminosity15W; stirring, 120 RPM; source of nitrogen, 1.5 g/L; and micronutrients, 0.75 mL/L.A Spirulina platensis é uma cianobactéria mesofílica, fotoautotrófica, que utiliza como nutrientes os nitratos, ureia e sais de amônio. O cultivo necessita de controle de temperatura, intensidade de luz e do teor de nutrientes utilizados. Esta microalga tem sido estuda pelo seu potencial nutricional, antioxidante, terapêutico e adjuvante em tratamento de obesidade. O objetivo deste trabalho foi a produção de biomassa de S. platensis em diferentes níveis de agitação, fonte de nitrog

  7. Phyocyanin extraction from microalgae Spirulina platensis assisted by ultrasound irradiation: effect of time and temperature

    Directory of Open Access Journals (Sweden)

    Hadiyanto

    2016-08-01

    Full Text Available This research was aimed to extract phycocyanin from microalgae Spirulina platensis using an extraction assisted by ultrasound irradiation. The extraction was conducted by using variable of extraction time, temperature and ultrasound frequency, while ethanol was used as solvent. The results show that the yield of phycocyanin extract was 15.97% at constant frequency of 42 kHz and 11.24% at constant frequency of 28 kHz, while the soxhlet extraction method obtained yield at 11.13%. The ultrasound could reduce the extraction time from 4 hrs (conventional to 20 minutes, while the optimum temperature of extraction was found at 55°C.

  8. Utjecaj praška Spiruline platensis na mikrofloru jogurta i acidofilnog mlijeka

    OpenAIRE

    Guldas, Metin; Irkin, Reyhan

    2010-01-01

    Glavni cilj ovog istraživanja bio je ispitivanje utjecaja dodatka praškastog Cyanobacterium Spirulina platensis u jogurt te jogurt obogaćen s Lactobacillus acidophilus na preživljavanje mikroorganizama tijekom čuvanja u hladnjaku. Ispitivano je preživljavanje starter kulture jogurta (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus) te Lactobacillus acidophilus u uzorcima pripremljenim uz dodatak 0,5 % ili 1 % (w/w) te bez dodatka spiruline, nakon čuvan...

  9. Alteration of the biomass composition of Arthrospira (Spirulina) platensis under various amounts of limited phosphorus.

    Science.gov (United States)

    Markou, Giorgos

    2012-07-01

    In this study the biomass composition alteration of the cyanobacterium Arthrospira (Spirulina) platensis under various amounts of limited phosphorus is studied. It was observed that the alteration of the compounds of the biomass occurred gradually as the phosphorus became limited. Carbohydrates and lipids increased from about 9% up to 65% and from about 4.9% up to 7.5%, respectively, while proteins decreased from about 46.5% to 25% as the phosphorus became limited. The increasing of carbohydrates and lipids in addition to the decrease of proteins resulted to an increase of the carbon to nitrogen (C/N) ratio from about 4.6 to 12.2.

  10. Kinetic and bioenergetic studies of Spirulina platensis in chemostat and turbidostat culture

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.Y.; Erickson, L.E.; Scott, C.D. (ed.)

    1986-01-01

    The growth kinetics and bioenergetics of S. platensis were investigated as a function of pH, temperature, light intensity, and HCO/sub 3/ concentration. The effects of pH and temperature on growth rate and bioenergetic yield were examined using turbidostat operation. The Arrhenius activation energy for growth appears to be independent of light intensity for the range of values that were investigated. Under light-limited growth conditions, the values of pH and temperature which provide for the maximum growth rate also correspond to the maximum bioenergetic yield. Chemostat operation was used to investigate C-limited growth.

  11. Extraction and purification of C-phycocyanin from Spirulina platensis (CCC540)

    OpenAIRE

    Kumar, Devendra; Dhar, Dolly Wattal; Pabbi, Sunil; Kumar, Neeraj; Walia, Suresh

    2014-01-01

    In this study a simple protocol was developed for purifying phycocyanin (PC) from Spirulina platensis (CCC540) by using ammonium sulphate precipitation, followed by a single step chromatography by using DEAE-Cellulose-11 and acetate buffer. Precipitation with 65 % ammonium sulphate resulted in 80 % recovery of phycocyanin with purity of 1.5 (A620/A280). Thro1ugh chromatography an 80 % recovery of phycocyanin with a purity of 4.5 (A620/A280) was achieved. In SDS_PAGE analysis, the purified PC ...

  12. Extraction and purification of C-phycocyanin from Spirulina platensis (CCC540).

    Science.gov (United States)

    Kumar, Devendra; Dhar, Dolly Wattal; Pabbi, Sunil; Kumar, Neeraj; Walia, Suresh

    2014-01-01

    In this study a simple protocol was developed for purifying phycocyanin (PC) from Spirulina platensis (CCC540) by using ammonium sulphate precipitation, followed by a single step chromatography by using DEAE-Cellulose-11 and acetate buffer. Precipitation with 65 % ammonium sulphate resulted in 80 % recovery of phycocyanin with purity of 1.5 (A620/A280). Thro1ugh chromatography an 80 % recovery of phycocyanin with a purity of 4.5 (A620/A280) was achieved. In SDS_PAGE analysis, the purified PC showed the presence of two subunit α (16 kD) and β (17 kD).

  13. Isolation of plasmid from the blue-green alga Spirulina platensis

    Science.gov (United States)

    Qin, Song; Tong, Shun; Zhang, Peijun; Tseng, C. K.

    1993-09-01

    CCC plasmid was isolated from an economically important blue-green alga — Spirulina platensis (1.7×106 dalton from the S6 strain and 1.2×106 dalton from the F3 strain) using a rapid method based on ultrasonic disruption of algal cells and alkaline removal of chromosomal DNA. The difference in the molecular weight of the CCC DNAs from the two strains differing in form suggests that plasmid may be related with the differentiation of algal form. This modified method, which does not use any lysozyme, is a quick and effective method of plasmid isolation, especially for filamentous blue-green algae.

  14. Langmuir-Blodgett film of phycobilisomes from blue-green alga Spirulina platensis.

    Science.gov (United States)

    Chen, Chao; Zhang, Yu-Zhong; Chen, Xiu-Lan; Zhou, Bai-Cheng; Gao, Hong-Jun

    2003-10-01

    The phycobilisomes were isolated from blue-green alga Spirulina platensis, and could form monolayer film at air/water interface. The monolayer film of phycobilisomes was transferred to newly cleaved mica, and coated with gold. Scanning tunneling microscope was used to investigate the structure of the Langmuir-Blodgett film of phycobilisomes. It was shown that phycobilisomes in the monolayer arrayed in rows with core attaching on the substrate surface and rods radiating towards the air phase, this phenomenon was similar to the arrangement of phycobilisomes on cytoplasmic surface of thylakoid membrane in vivo. The possible applications of the Langmuir-Blodgett film of phycobilisomes were also discussed.

  15. Nutrient composition of Spirulina platensis grown on digested domestic wastewater%生活废水培养螺旋藻(Spirulina platensis)中的营养物质构成

    Institute of Scientific and Technical Information of China (English)

    黄昆; 张逸波; 黄峙; 郑文杰

    2009-01-01

    研究生活废水培养螺旋藻(Spirulina platensis,SP)中的主要营养物质构成.用厨房废水(kitchenwastewater,KW)摇瓶培养SP,观察藻细胞在KW中的生长状态,以及低、高光照强度(36 μmol/m~2·S和108μmol/m~2·s)对SP生长的影响.化学比色法检测KW培养的sP(KW-SP)中的总蛋白质(Pr)、脂(Lip)和水溶性多糖(Ploys)等主要营养物质的构成.结果发现,SP在KW中的生长速率、生物量及产率可达在Zarrouk培养液(ZM)中的80%以上,并表现有明显氮营养缺乏特点;与ZM培养的SP(ZM-sp)相比,低、高光照强度下培养的KW-SP中Pr(分别占干质量的47.7%和40.3%)明显降低(P<0.05),Lip(26.5%和19.3%)显著增高(P<0.05),高光照强度下培养的KW-SP中Ploys(24.1%)显著增高(P<0.05);KW-SP中天冬氨酸(Asp)和蛋氨酸含量明显增加(P<0.05),精氨酸、组氨酸和胱氨酸含量则明显降低(P<0.05).用生活废水培养的SP营养价值仍然较高,培养过程中氮缺乏和光照强度对KW-SP中蛋白质、脂、多糖及氨基酸构成有重要影响.%Evaluation of nutrient composition of Spirulina platensis (SP) grown on domestic wastewater (DW) was undertaken. SP cultivation was carried out in digested kitchen waster (KW) either at a light flx of 36(lower )or 108 mlo photon /m~2·s(higher),utiling shaking flasks,Conterts of total protein, lipids and water soluble polysaccharides were determined by colorimetric methods. Al-though SP cultivation in DW displayed nitrogen deficiency, the special growth rate and biomass concen-tration (as dry weight) after 10 days of cultivation in the DW was above 80% to the one observed in Zar-rouk medium (ZM), regardless of the light intensity. Compared to the SP grown on ZM (ZM-SP), the protein and the total lipids contents of the biomass in SP grown on KW (KW-SP) were significantly de-creased (P<0.05), regardless of the light flux. However, the water soluble polysaccharide was obvious-ly enriched in KW-SP (21.4%) at the higher light

  16. Cultivation of Chlorella vulgaris and Arthrospira platensis with recovered phosphorus from wastewater by means of zeolite sorption.

    Science.gov (United States)

    Markou, Giorgos; Depraetere, Orily; Vandamme, Dries; Muylaert, Koenraad

    2015-02-16

    In this study, zeolite was employed for the separation and recovery of P from synthetic wastewater and its use as phosphorus (P) source for the cultivation of the green microalga Chlorella vulgaris and the cyanobacterium Arthrospira (Spirulina) platensis. At P-loaded zeolite concentration of 0.15-1 g/L, in which P was limited, the two species displayed quite different behavior regarding their growth and biomass composition. C. vulgaris preferred to increase the intracellular P and did not synthesize biomass, while A. platensis synthesized biomass keeping the intracellular P as low as possible. In addition under P limitation, C. vulgaris did display some little alteration of the biomass composition, while A. platensis did it significantly, accumulating carbohydrates around 70% from about 15%-20% (control). Both species could desorb P from zeolite biologically. A. platensis could recover over 65% and C. vulgaris 25% of the P bounded onto zeolite. When P-loaded zeolite concentration increased to 5 g/L, P was adequate to support growth for both species. Especially in the case of C. vulgaris, growth was stimulated from the presence of P-loaded zeolite and produced more biomass compared to the control.

  17. Cultivation of Chlorella vulgaris and Arthrospira platensis with Recovered Phosphorus from Wastewater by Means of Zeolite Sorption

    Directory of Open Access Journals (Sweden)

    Giorgos Markou

    2015-02-01

    Full Text Available In this study, zeolite was employed for the separation and recovery of P from synthetic wastewater and its use as phosphorus (P source for the cultivation of the green microalga Chlorella vulgaris and the cyanobacterium Arthrospira (Spirulina platensis. At P-loaded zeolite concentration of 0.15–1 g/L, in which P was limited, the two species displayed quite different behavior regarding their growth and biomass composition. C. vulgaris preferred to increase the intracellular P and did not synthesize biomass, while A. platensis synthesized biomass keeping the intracellular P as low as possible. In addition under P limitation, C. vulgaris did display some little alteration of the biomass composition, while A. platensis did it significantly, accumulating carbohydrates around 70% from about 15%–20% (control. Both species could desorb P from zeolite biologically. A. platensis could recover over 65% and C. vulgaris 25% of the P bounded onto zeolite. When P-loaded zeolite concentration increased to 5 g/L, P was adequate to support growth for both species. Especially in the case of C. vulgaris, growth was stimulated from the presence of P-loaded zeolite and produced more biomass compared to the control.

  18. Antioxidant Potential of Spirulina platensis Mitigates Oxidative Stress and Reprotoxicity Induced by Sodium Arsenite in Male Rats

    Directory of Open Access Journals (Sweden)

    Samir A. E. Bashandy

    2016-01-01

    Full Text Available The present study aimed to examine the protective role of Spirulina platensis (S. platensis against arsenic-induced testicular oxidative damage in rats. Arsenic (in the form of NaAsO2 at a dose of 6.3 mg/kg body weight for 8 weeks caused a significant accumulation of arsenic in testicular tissues as well as a decrease in the levels of testicular superoxide dismutase (SOD, catalase (CAT, reduced glutathione, and zinc. Moreover, it significantly decreased plasma testosterone, luteinizing hormone (LH, triiodothyronine (T3, and thyroxine (T4 levels and reduced sperm motility and sperm count. Arsenic (AS led to a significant increase in testicular malondialdehyde (MDA, tumour necrosis factor alpha (TNF-α, nitric oxide (NO, and sperm abnormalities. S. platensis at a dose of 300 mg/kg was found to attenuate As-induced oxidative stress, testicular damage, and sperm abnormalities by its potent antioxidant activity. S. platensis may represent a potential therapeutic option to protect the testicular tissue from arsenic intoxication.

  19. Perpendicularly Aligned, Anion Conducting Nanochannels in Block Copolymer Electrolyte Films

    Energy Technology Data Exchange (ETDEWEB)

    Arges, Christopher G.; Kambe, Yu; Suh, Hyo Seon; Ocola, Leonidas E.; Nealey, Paul F.

    2016-03-08

    Connecting structure and morphology to bulk transport properties, such as ionic conductivity, in nanostructured polymer electrolyte materials is a difficult proposition because of the challenge to precisely and accurately control order and the orientation of the ionic domains in such polymeric films. In this work, poly(styrene-block-2-vinylpyridine) (PSbP2VP) block copolymers were assembled perpendicularly to a substrate surface over large areas through chemical surface modification at the substrate and utilizing a versatile solvent vapor annealing (SVA) technique. After block copolymer assembly, a novel chemical vapor infiltration reaction (CVIR) technique selectively converted the 2-vinylpyridine block to 2-vinyl n-methylpyridinium (NMP+ X-) groups, which are anion charge carriers. The prepared block copolymer electrolytes maintained their orientation and ordered nanostructure upon the selective introduction of ion moieties into the P2VP block and post ion-exchange to other counterion forms (X- = chloride, hydroxide, etc.). The prepared block copolymer electrolyte films demonstrated high chloride ion conductivities, 45 mS cm(-1) at 20 degrees C in deionized water, the highest chloride ion conductivity for anion conducting polymer electrolyte films. Additionally, straight-line lamellae of block copolymer electrolytes were realized using chemoepitaxy and density multiplication. The devised scheme allowed for precise and accurate control of orientation of ionic domains in nanostructured polymer electrolyte films and enables a platform for future studies that examines the relationship between polymer electrolyte structure and ion transport.

  20. Bacterias halotolerantes/alcalofilas productoras de acido indol acético (AIA asociadas a Arthrospira platensis (Cyanophyceae

    Directory of Open Access Journals (Sweden)

    Liliana Cecilia Gómez Gómez

    2012-08-01

    Full Text Available Título en ingles: Halotolerant alkalophilic and indolacetic acid producing acid producing bacteria associated with Arthrospira platensis (Cyanophyceae Resumen: Este trabajo tuvo como propósito contribuir al conocimiento de la interacción entre la cianobacteria alcalófila Arthrospira platensis y las bacterias que crecen asociadas a su mucilago. Se desarrolló un  medio de cultivo heterotrófico en el cual se aislaron cinco cepas bacterianas asociadas a un monocultivo de A. platensis. Se determinó la capacidad de estas cinco cepas para producir ácido 3- indol acético (AIA. La tipificación molecular de los aislamientos bacterianos permitió identificarlos como Exiguobacterium aurantiacum str. DSM 20416, Xanthomonas sp. ML-122, Halomonas sp. Ap-5, Bacillus okhensis str.  Kh10-101, Indibacter alkaliphilus, type str. LW1T; todas las cepas bacterianas obtenidas  son halotolerantes, alcalófilas y productoras de AIA. Los resultados aportan evidencia para sugerir una interacción benéfica entre A. platensis y sus bacterias asociadas,  quizá como estrategia evolutiva  de cooperación para desarrollarse en  un ambiente hipersalino.    Palabras claves: Bacillus okhensis, Exiguobacterium aurantiacum, Halomonas sp., Indibacter alkaliphilus. Xanthomonas sp. Abstract: The aim of this study was contribute to knowledge over alkalophilic cianobacteryum  Arthrospira platensis  and their  interaction with some associated bacteria growing in their mucilage. Heterotrophic culture medium was designed, in this medium were isolated five bacterial strains associated to single culture of A. platensis. It was measured the 3-indol acetic acid (IAA production by these bacterial strains. Molecular typing allowed identify these bacterial strains like Exiguobacterium aurantiacum str. DSM 20416, Xanthomonas sp. ML-122, Halomonas sp. Ap-5, Bacillus okhensis str. Kh10-101, Indibacter alkaliphilus, type str. LW1T; all these bacteria are halotolerant

  1. Nutritional and Physicochemical Characteristics of Bread Enriched with Microalgae Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Burcu Ak

    2016-12-01

    Full Text Available The aim of this study was to increase the nutrient content of bread prepared with white flour, using the valuable metabolites included in Spirulina platensis. In this study, conventional breads were added 10% of Spirulina. The nutrient composition, protein and lipid content were evaluated and microbiological and sensory analyses were conducted in the breads with microalgal biomass. The addition of microalgal biomass resulted in protein content increase, ranging from 7.40% to 11.63%. While Calcium, Magnesium and Iron contents of bread with S. platensis were 721.2, 336.6, 41.12ppm, conventional bread contained 261.7ppm Calcium, 196ppm Magnesium, and 8.72ppm Iron. Enrichment with Spirulina had significant influence on the volatile compounds of bread. By using the HS/SPME/GC/MS technique, fourteen volatile compounds were detected in control group and ten compounds were detected in bread with Spirulina. The results for the sensory assessment of bread enriched with Spirulina were considered satisfactory even if some algae flavor in the samples were perceived. Besides, bread with Spirulina stored at room conditions was observed to have a positive effect on the inhibition of mold growth. According to these results, the use of microalgae can enhance nutritional quality of bread without a negative impact on the shelf life of bread.

  2. Antibacterial and anticancerous biocompatible silver nanoparticles synthesised from the cold-tolerant strain of Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Selvaraj Karthick Raja Namasivayam

    2015-04-01

    Full Text Available Objective: To synthesize silver nanoparticles from the biomass of cold tolerant strain of Spirulina platensis and evalute the synthesized nanoparticles against antibacterial and anticancer activity. Methods: Silver nanoparticles were synthesized by the algal culture and characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and X ray diffraction studies. Antibacterial activity has been studied with free nanoparticles adopting agar diffusion assay, biofilm inhibition assay and nanoparticles fabricated wound dressing against representative Gram-negative organism Pseudomonas aeruginosa and Gram-positive organism Staphylococcus aureus respectively. The in vitro anticancer activity of silver nanoparticles were screened against human Hep2 cell lines by means of MTT assay. Results: Reduction of silver ions by the algal culture was observed during 72 h of incubation and the synthesized nanoparticles were further characterized. Antibacterial study reveals both the strains were susceptible to free nanoparticles and fabricated wound dressing treatment. The in vitro anticancer activity of silver nanoparticles were screened against human Hep 2 cell lines by means of MTT assay which reveals that cell viability has been reduced as dose dependent manner. Conclusions: The observed results imply that silver nanoparticles synthesized from Spirulina platensis cold tolerant strain can be used as potential antibacterial and anticancerous agent.

  3. Biological Synthesis of Silver Nanoparticles by Cell-Free Extract of Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Gaurav Sharma

    2015-01-01

    Full Text Available The present study explores biological synthesis of silver nanoparticles (AgNPs using the cell-free extract of Spirulina platensis. Biosynthesised AgNPs were characterised by UV-Vis spectroscopy, SEM, TEM, and FTIR analysis and finally evaluated for antibacterial activity. Extracellular synthesis using aqueous extract of S. platensis showed the formation of well scattered, highly stable, spherical AgNPs with an average size of 30–50 nm. The size and morphology of the nanoparticles were confirmed by SEM and TEM analysis. FTIR and UV-Vis spectra showed that biomolecules, proteins and peptides, are mainly responsible for the formation and stabilisation of AgNPs. Furthermore, the synthesised nanoparticles exhibited high antibacterial activity against pathogenic Gram-negative, that is, Escherichia coli, MTCC-9721; Proteus vulgaris, MTCC-7299; Klebsiella pneumoniae, MTCC-9751, and Gram-positive, that is, Staphylococcus aureus, MTCC-9542; S. epidermidis, MTCC-2639; Bacillus cereus, MTCC-9017, bacteria. The AgNPs had shown maximum zone of inhibition (ZOI that is 31.3±1.11 in P. vulgaris. Use of such a microalgal system provides a simple, cost-effective alternative template for the biosynthesis of nanomaterials of silver in a large scale that could be of great use in biomedical applications.

  4. Phycocyanin Extraction from Spirulina platensis and Its Antimalarial Activity In-Vitro

    Directory of Open Access Journals (Sweden)

    Diah Anggraini Wulandari

    2016-04-01

    Full Text Available Phycocyanin is a pigment-protein complex from the light-harvesting phycobiliprotein family which isoften found in cyanobacteria. The product phycocyanin produced by phanizomenon flos-aquae and Spirulinasp. The aim of this study were to determine the best solvents purification phycocanin from Spirulina platensisin three solvents, phosphate buffer, water and aceton ammonium sulphate and to evaluate the antimalarialactivity in vitro of phycocyanin in the best solvent extraction from S. platensis. The method of this study wasusing in-vitro antimalarial method. The result showed C- phycocyanin (C-PC, yield, and protein contentsof phycocyanin were 8 mg/mL, 20.22%, 1.88% extracted and purified by phosphate buffer, 6.63 mg/mL,16.58 %, 3.51% extracted and purified by water, 2.86 mg/mL, 7.15%, 8.4% extracted and purified by acetoneammonium sulphate respectively. Phosphate buffer was the best solvent of phycocyanin extraction from S.platensis. Antimalarial activity in vitro of phycocyanin in hosphate buffer against Plasmodium falciparumstrains 3D7 with IC50 was 158,489 μg/mL. The possible mechanism might be relied on the destruction ofpolymerization of Haemozoin by binding of C-PC with ferriprotoporphyrin-IX at the water surface of theplasma membrane.

  5. Photoregulation of morphological structure and its physiological relevance in the cyanobacterium Arthrospira (Spirulina) platensis.

    Science.gov (United States)

    Ma, Zengling; Gao, Kunshan

    2009-07-01

    The spiral structure of the cyanobacterium Arthrospira (Spirulina) platensis (Nordst.) Gomont was previously found to be altered by solar ultraviolet radiation (UVR, 280-400 nm). However, how photosynthetic active radiation (PAR, 400-700 nm) and UVR interact in regulating this morphological change remains unknown. Here, we show that the spiral structure of A. platensis (D-0083) was compressed under PAR alone at 30 degrees C, but that at 20 degrees C, the spirals compressed only when exposed to PAR with added UVR, and that UVR alone (the PAR was filtered out) did not tighten the spiral structure, although its presence accelerated morphological regulation by PAR. Their helix pitch decreased linearly as the cells received increased PAR doses, and was reversible when they were transferred back to low PAR levels. SDS-PAGE analysis showed that a 52.0 kDa periplasmic protein was more abundant in tighter filaments, which may have been responsible for the spiral compression. This spiral change together with the increased abundance of the protein made the cells more resistant to high PAR as well as UVR, resulting in a higher photochemical yield.

  6. Chlorophylls, proteins and fatty acids amounts of arthrospira platensis growing under saline conditions.

    Science.gov (United States)

    Ayachi, Samah; El Abed, Amor; Dhifi, Wissal; Marzouk, Brahim

    2007-07-15

    Spirulina platensis (Arthrospira platensis) is a Tunisian strain isolated for the first time, in Tunisia, in Oued Essed (Sidi Bou Ali, in Sousse region). Evolution of biomass, proteins, chlorophylls and fatty acids (FA) has been followed during Spirulina growth. Experiments were carried out by varying sodium chloride concentrations in the culture medium in a range from 1 g L(-1) (natural environment) to 60 g L(-1). Results analysis showed an increase in chlorophyll amounts at 15 g L(-1) NaCl in 10 days old cultures but a decrease at high NaCl concentrations. Optimal proteins amounts was observed at 15 g L(-1) NaCl in young cultures (5 and 10 days). FA composition was modified by NaCl and depended on culture age. Cultures exposed to high salinity concentrations showed not only a decrease in growth rate but also a loss in total fatty acids TFA quantities. Samples cultured over 15 days at 30 g L(-1) NaCl rendered optimal quantities of lipids and gamma-linolenic acid.

  7. Antibacterial and anticancerous biocompatible silver nanoparticles synthesised from the cold-tolerant strain of Spirulina platensis

    Institute of Scientific and Technical Information of China (English)

    Duraisamy Jayakumar; Ramesh Kumar; Rajan SowriArvind Bharani

    2015-01-01

    Objective: To synthesize silver nanoparticles from the biomass of cold tolerant strain of Spirulina platensis and evalute the synthesized nanoparticles against antibacterial and anticancer activity. Methods: Silver nanoparticles were synthesized by the algal culture and characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and X ray diffraction studies. Antibacterial activity has been studied with free nanoparticles adopting agar diffusion assay, biofilm inhibition assay and nanoparticles fabricated wound dressing against representative Gram-negative organism Pseudomonas aeruginosa and Gram-positive organism Staphylococcus aureus respectively. The in vitro anticancer activity of silver nanoparticles were screened against human Hep2 cell lines by means of MTT assay. Results: Reduction of silver ions by the algal culture was observed during 72 h of incubation and the synthesized nanoparticles were further characterized. Antibacterial study reveals both the strains were susceptible to free nanoparticles and fabricated wound dressing treatment. The in vitro anticancer activity of silver nanoparticles were screened against human Hep 2 cell lines by means of MTT assay which reveals that cell viability has been reduced as dose dependent manner. Conclusions: The observed results imply that silver nanoparticles synthesized from Spirulina platensis cold tolerant strain can be used as potential antibacterial and anticancerous agent.

  8. Behavioral and Histopathological Study of Changes in Spinal Cord Injured Rats Supplemented with Spirulina platensis

    Science.gov (United States)

    Che Ramli, Muhammad Danial

    2014-01-01

    Spinal cord injury (SCI) is a devastating disease that leads to permanent disability and causes great suffering. The resulting neurological dysfunction and paralysis is proportional to the severity of the trauma itself. Spirulina is widely used as a nutritional supplement due to its high protein and antioxidant content. In the present study, the protective effect of the Spirulina treatment on locomotor function and morphological damage after SCI was investigated. Seventy Sprague-Dawley (SD) rats were divided into three groups: Sham (laminectomy alone), Control (laminectomy with SCI), and Experimental (laminectomy with SCI +180 mg/kg per day Spirulina platensis). A laminectomy was performed at T12 and an Inox No.2 modified forceps was used to perform a partial crush injury on the spinal cord. The rats were then perfused at 3, 7, 14, 21, and 28 days after injury for morphological investigations. The injured rat spinal cord indicated a presence of hemorrhage, cavity, and necrosis. Pretreatment with Spirulina significantly improved the locomotor function and showed a significant reduction on the histological changes. The experimental results observed in this study suggest that treatment with Spirulina platensis possesses potential benefits in improving hind limb locomotor function and reducing morphological damage to the spinal cord. PMID:25152764

  9. Effect of pH on the functional properties of Arthrospira (Spirulina) platensis protein isolate.

    Science.gov (United States)

    Benelhadj, Sonda; Gharsallaoui, Adem; Degraeve, Pascal; Attia, Hamadi; Ghorbel, Dorra

    2016-03-01

    In the present study, a protein isolate extracted from Arthrospira platensis by isoelectric precipitation was evaluated for its functional properties. The maximum nitrogen solubility was 59.6±0.7% (w/w) at pH 10. The A. platensis protein isolate (API) showed relatively high oil (252.7±0.3g oil/100g API) and water (428.8±15.4g of water/100g of API at pH 10) absorption capacities. The protein zeta potential, the emulsifying capacity, the emulsion ageing stability, the emulsion microstructure and the emulsion opacity as well as the foaming capacity and the foam stability were shown to be greatly affected by pH. Especially, emulsifying and foaming capacities were positively correlated to the protein solubility. Moreover, the API was able to form films when sorbitol (30% (w/w)) was used as plasticizer and to form gels when the API concentration exceeded 12% (w/w).

  10. Behavioral and Histopathological Study of Changes in Spinal Cord Injured Rats Supplemented with Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Izzuddin Aziz

    2014-01-01

    Full Text Available Spinal cord injury (SCI is a devastating disease that leads to permanent disability and causes great suffering. The resulting neurological dysfunction and paralysis is proportional to the severity of the trauma itself. Spirulina is widely used as a nutritional supplement due to its high protein and antioxidant content. In the present study, the protective effect of the Spirulina treatment on locomotor function and morphological damage after SCI was investigated. Seventy Sprague-Dawley (SD rats were divided into three groups: Sham (laminectomy alone, Control (laminectomy with SCI, and Experimental (laminectomy with SCI +180 mg/kg per day Spirulina platensis. A laminectomy was performed at T12 and an Inox No.2 modified forceps was used to perform a partial crush injury on the spinal cord. The rats were then perfused at 3, 7, 14, 21, and 28 days after injury for morphological investigations. The injured rat spinal cord indicated a presence of hemorrhage, cavity, and necrosis. Pretreatment with Spirulina significantly improved the locomotor function and showed a significant reduction on the histological changes. The experimental results observed in this study suggest that treatment with Spirulina platensis possesses potential benefits in improving hind limb locomotor function and reducing morphological damage to the spinal cord.

  11. Purification and Identification of Antioxidant Peptides from Enzymatic Hydrolysate of Spirulina platensis.

    Science.gov (United States)

    Yu, Jie; Hu, Yuanliang; Xue, Mingxiong; Dun, Yaohao; Li, Shenao; Peng, Nan; Liang, Yunxiang; Zhao, Shumao

    2016-07-28

    The aim of this study was to isolate antioxidant peptides from an enzymatic hydrolysate of Spirulina platensis. A novel antioxidant peptide was obtained by ultrafiltration, gel filtration chromatography, and reverse-phase high-performance liquid chromatography, with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay used to measure the antioxidant activity, and the sequence was determined to be Pro-Asn-Asn (343.15 Da) by electrospray ionization tandem mass spectrometry. This peptide was synthesized to confirm its antioxidant properties, and it exhibited 81.44 ± 0.43% DPPH scavenging activity at 100 µg/ml, which was similar to that of glutathione (82.63 ± 0.56%). Furthermore, the superoxide anion and hydroxyl free-radical scavenging activities and the SOD activity of the peptide were 47.84 ± 0.49%, 54.01 ± 0.82%, and 12.55 ± 0.75%, respectively, at 10 mg/ml. These results indicate that S. platensis is a good source of antioxidant peptides, and that its hydrolysate may have important applications in the pharmaceutical and food industries.

  12. Isolation and identification of anti-proliferative peptides from Spirulina platensis using three-step hydrolysis.

    Science.gov (United States)

    Wang, Zhujun; Zhang, Xuewu

    2017-02-01

    Spirulina platensis is an excellent source of proteins (>60%) that can be hydrolyzed into bioactive peptides. In this study, whole proteins of Spirulina platensis were extracted and hydrolyzed using three gastrointestinal endopeptidases (pepsin, trypsin and chymotrypsin). Subsequently, gel filtration chromatography was employed to separate hydrolysates, and four fractions (Tr1-Tr4) were obtained. Among them, Tr2 showed the strongest anti-proliferation activities on three cancer cells (MCF-7, HepG-2 and SGC-7901), with IC50 values of <31.25, 36.42 and 48.25 µg mL(-1) , respectively. Furthermore, a new peptide, HVLSRAPR, was identified from fraction Tr1. This peptide exhibited strong inhibition on HT-29 cancer cells with an IC50 value of 99.88 µg mL(-1) . Taken together, these peptides possessed anti-proliferation activities on cancer cells and low cytotoxicity on normal cells, suggesting that they might serve as a natural anticancer agent for nutraceutical and pharmaceutical industries. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  13. Cultivation of Arthrospira (Spirulina) platensis in olive-oil mill wastewater treated with sodium hypochlorite.

    Science.gov (United States)

    Markou, Giorgos; Chatzipavlidis, Iordanis; Georgakakis, Dimitris

    2012-05-01

    The subject of this paper is the cultivation of the cyanobacterium Arthrospira (Sprirulina) platensis in olive-oil mill wastewater (OMWW) treated with sodium hypochlorite (NaOCl). The main positive effect of NaOCl on the OMWW characteristics is the decrease of the phenol concentration and turbidity, rendering the OMWW suitable for A. platensis growth. Maximum biomass production (1696 mg/l) was obtained when the concentration of OMWW in the cultivation medium was 10% with the supplementation of 1g/l NaNO(3) and 5 g/l NaHCO(3). However, the addition of NaHCO(3) has no significant effect, indicating that the only limited nutrient in this wastewater is nitrogen, while carbon is provided by the organic compounds of the wastewater. The maximum of the removals of chemical oxygen demand (COD) and carbohydrates was 73.18% and 91.19%, respectively, while phenols, phosphorus and nitrates in some runs was completely removed.

  14. Protective effect of Spirulina platensis against cell damage and apoptosis in hepatic tissue caused by high fat diet.

    Science.gov (United States)

    Yigit, F; Gurel-Gurevin, E; Isbilen-Basok, B; Esener, O B B; Bilal, T; Keser, O; Altiner, A; Yilmazer, N; Ikitimur-Armutak, E I

    2016-01-01

    Spirulina platensis is a microalga that may be a source of antioxidants that can reduce body fat deposition. Consumption of a high fat diet produces elevated blood lipid levels, inflammation and apoptosis. We investigated the possible effects of S. platensis on the blood lipid profile, and liver inflammation and apoptosis in rats fed a high fat diet. Sixty-four young male rats were divided into eight equal groups. The control group was fed a basic diet. The experimental groups were fed a diet for 60 days that was prepared by mixing variable amounts of 43% vegetable oil and 10% cholesterol with or without 3% S. platensis mixed with the basal diet. Blood and liver tissue samples were collected from each animal. Serum samples were used to analyze lipid parameters, total antioxidant status and total oxidant status. iNOS and eNOS were determined by immunohistochemistry. TUNEL staining was used to detect apoptosis to investigate a possible connection between inflammation and apoptosis in the liver tissue. The relations between fat deposition and liver degeneration were assessed by Sirius red staining and alpha-smooth muscle actin immunostaining. S. platensis reduced serum HDL-C, LDL-C and triglyceride, increased HDL-C levels in rats fed a high fat diet to near control levels, and reduced iNOS levels and increased eNOS levels in the liver tissue compared to vegetable oil and cholesterol treated groups. The apoptotic index was reduced in the groups that were fed a high fat or a basic diet when supplemented with S. platensis.

  15. The AplI restriction-modification system in an edible cyanobacterium, Arthrospira (Spirulina) platensis NIES-39, recognizes the nucleotide sequence 5'-CTGCAG-3'.

    OpenAIRE

    2013-01-01

    The degradation of foreign DNAs by restriction enzymes in an edible cyanobacterium, Arthrospira platensis, is a potential barrier for gene-transfer experiments in this economically valuable organism. We overproduced in Escherichia coli the proteins involved in a putative restriction-modification system of A. platensis NIES-39. The protein produced from the putative type II restriction enzyme gene NIES39_K04640 exhibited an endonuclease activity that cleaved DNA within the sequence 5'-CTGCAG-3...

  16. Nanopatterned CoPt alloys with perpendicular magnetic anisotropy

    Science.gov (United States)

    Makarov, D.; Bermúdez-Ureña, E.; Schmidt, O. G.; Liscio, F.; Maret, M.; Brombacher, C.; Schulze, S.; Hietschold, M.; Albrecht, M.

    2008-10-01

    CoPt alloy films with perpendicular magnetic anisotropy were grown on SiO2 nanoparticle arrays with particle sizes as small as 10 nm. In order to induce perpendicular magnetic anisotropy in the CoPt film, a MgO seed layer was sputter deposited. Despite the fact that neighboring CoPt film caps are interconnected, individual caps appear as single domain and for most of them their magnetization orientation can be reversed individually. This behavior might be caused by domain wall nucleation and pinning preferentially at the rim of each cap. Thus, arrays of magnetic caps with defined pinning sites can be considered as a percolated perpendicular medium.

  17. Pão sem gluten enriquecido com a microalga Spirulina platensis Elaboration of gluten-free bread enriched with the microalgae Spirulina platensis

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    Felipe da Silva Figueira

    2011-12-01

    Full Text Available Com a finalidade de oferecer pão sem glúten para consumidores com síndrome celíaca, em razão da intolerância ao glúten, elaboraram-se produtos com farinha de arroz em substituição à farinha de trigo. Para aumentar o conteúdo proteico dos pães adicionou-se a microalga Spirulina platensis seca, na faixa de 2 a 5% (base farinha. Os pães foram avaliados pelo volume específico, dureza do miolo uma e 24h após o forneamento e a cor do miolo. Verificou-se que o volume específico e a dureza dos pães não sofreram alteração com a adição de até 4% da alga, porem mostraram redução de 22% nos valores de volume e aumento de 113% na dureza quando se adicionou-se 5% (em base de farinha. Quando comparados ao pão não enriquecido, a adição de Spiriulina platensis provocou uma melhoria da qualidade nutricional dos pães, confirmada pelo aumento significativo de 39,04% do conteúdo protéico, alem de vários aminoácidos essenciais (treonina, metionina, isoleucina e leucina. Com relação a cor, os pães com Spirulina apresentaram redução de luminosidade com o aumento de adição de microalga, sendo também observada tendência de aumento de tonalidade verde. Na avaliação sensorial, não se verificou diferença significativa quanto a preferência entre os pães adicionados com 3% e 5% de Spirulina na formulação.With the objective of offering a product for people with celiac disease, due to their gluten intolerance, gluten-free bread made with rice flour was elaborated, in substitution of the wheat flour. To increase the protein content of the bread, dried Spirulina platensis, a microalga, was added to the products in the range from 2 to 5% (flour basis. The bread samples were evaluated according to their specific volume (V/W, crumb hardness, measured with a texturometer, and the crumb color. It was shown that the specific volume and crumb hardness were not affected by the addition of up to 4% of alga, but a decrease of 22% in the

  18. Spirulina platensis effects on the levels of total cholesterol, HDL and triacylglycerols in rabbits fed with a hypercholesterolemic diet

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    Luciane Maria Colla

    2008-04-01

    Full Text Available In this work, hypercholesterolemia was induced in rabbits by feeding them a high cholesterol diet (CD, 350 mg/d and the effects of supplementing this diet with 0.5 g/d Spirulina platensis was evaluated by measuring the levels of serum total-cholesterol (TC, triacylglycerols (TAG and high-density lipoprotein (HDL-cholesterol at the start of the experiment and after 30 d and 60 d. It was found that the levels of serum cholesterol decreased from 1,054±101 mg.dL-1 in the rabbits fed a CD without S. platensis to 516±163 mg.dL-1 to those fed with a high cholesterol diet supplemented with S. platensis (significant at p A microalga Spirulina é cultivada e comercializada no mundo devido a suas características nutricionais (elevada concentração de proteínas, em torno de 65%, vitaminas e sais minerais e ao seu potencial terapêutico no tratamento de inúmeras doenças, inclusive a hipercolesterolemia. Neste trabalho foi avaliada a inibição da hipercolesterolemia induzida em coelhos por uma dieta adicionada de colesterol (350 mg.d-1, pela suplementação de 0,5 g.dia-1 de biomassa de Spirulina platensis, sendo avaliados os níveis de colesterol total, triglicerídeos e HDL nos tempos de 0 d, 30 d e 60 d de tratamento. Os resultados indicaram que a adição de Spirulina platensis na dieta ocasionou decréscimo nos níveis de colesterol total de 1054±101 mg.dL-1 para 516±163 mg.dL-1 (p<0,0001, para os coelhos alimentados com a dieta colesterolêmica em comparação com os que receberam a dieta adicionada de Spirulina platensis. A adição de Spirulina a dieta colesterolêmica não ocasionou decréscimo significativo nos níveis de triglicerídios dos coelhos. Os valores de HDL aumentaram de 73±31 mg.dL-1 para 91,0±15,7 mg.dL-1, comparando-se os coelhos alimentados com a dieta colesterolêmica e os alimentados com a dieta adicionada de Spirulina, estatisticamente diferentes a um nível de significância maior que 0,1533.

  19. Improvement of mercuric chloride-induced testis injuries and sperm quality deteriorations by Spirulina platensis in rats.

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    Gaber E El-Desoky

    Full Text Available The present study was undertaken to investigate the protective effect of the filamentous cyanobacterium Spirulina platensis (S. platensis on mercury (II chloride (HgCl(2-induced oxidative damages and histopathological alterations in the testis of Wistar albino rats. The animals were divided into four equal groups, i control, ii HgCl(2, iii S. platensis and iv combination of HgCl(2+S. platensis. Oxidative stress, induced by a single dose of HgCl(2 (5 mg/kg, bw; subcutaneously, s.c., substantially decreased (P<0.01 the activity level of testicular key enzymatic antioxidant biomarkers (superoxide dismutase, SOD; catalase, CAT and glutathione peroxidase, GPx, oxidative stress makers (blood hydroperoxide; testicular reduced glutathione, GSH and malondialdehyde, MDA, and testicular mercury levels. Moreover, HgCl(2 administration resulted in a significant (P<0.01 increase in the number of sperms with abnormal morphology and decrease in epididymal sperm count, motility, plasma testosterone level and testicular cholesterol. Furthermore, HgCl(2 exposure induced histopathological changes to the testis including morphological alterations of the seminiferous tubules, and degeneration and dissociation of spermatogenic cells. Notably, oral pretreatment of animals with Spirulina (300 mg/kg, bw lowered the extent of the observed HgCl(2-mediated toxicity, whereby significantly reducing the resulting lipid peroxidation products, mercury accumulation in the testis, histopathological changes of the testes and spermatozoal abnormalities. In parallel, the pretreatment with Spirulina also completely reverted the observed Hg-Cl(2-induced inhibition in enzymatic activities of antioxidant biomarkers (SOD, CAT and GPx back to control levels. The pretreatment of rats with S. platensis significantly recovered the observed HgCl(2-mediated decrease in the weight of accessory sex organs. Taken together, our findings clearly highlight the role of S. platensis as a protective

  20. Improvement of Mercuric Chloride-Induced Testis Injuries and Sperm Quality Deteriorations by Spirulina platensis in Rats

    Science.gov (United States)

    El-Desoky, Gaber E.; Bashandy, Samir A.; Alhazza, Ibrahim M.; Al-Othman, Zeid A.; Aboul-Soud, Mourad A. M.; Yusuf, Kareem

    2013-01-01

    The present study was undertaken to investigate the protective effect of the filamentous cyanobacterium Spirulina platensis (S. platensis) on mercury (II) chloride (HgCl2)-induced oxidative damages and histopathological alterations in the testis of Wistar albino rats. The animals were divided into four equal groups, i) control, ii) HgCl2, iii) S. platensis and iv) combination of HgCl2+S. platensis. Oxidative stress, induced by a single dose of HgCl2 (5 mg/kg, bw; subcutaneously, s.c.), substantially decreased (P<0.01) the activity level of testicular key enzymatic antioxidant biomarkers (superoxide dismutase, SOD; catalase, CAT and glutathione peroxidase, GPx), oxidative stress makers (blood hydroperoxide; testicular reduced glutathione, GSH and malondialdehyde, MDA), and testicular mercury levels. Moreover, HgCl2 administration resulted in a significant (P<0.01) increase in the number of sperms with abnormal morphology and decrease in epididymal sperm count, motility, plasma testosterone level and testicular cholesterol. Furthermore, HgCl2 exposure induced histopathological changes to the testis including morphological alterations of the seminiferous tubules, and degeneration and dissociation of spermatogenic cells. Notably, oral pretreatment of animals with Spirulina (300 mg/kg, bw) lowered the extent of the observed HgCl2-mediated toxicity, whereby significantly reducing the resulting lipid peroxidation products, mercury accumulation in the testis, histopathological changes of the testes and spermatozoal abnormalities. In parallel, the pretreatment with Spirulina also completely reverted the observed Hg-Cl2-induced inhibition in enzymatic activities of antioxidant biomarkers (SOD, CAT and GPx) back to control levels. The pretreatment of rats with S. platensis significantly recovered the observed HgCl2-mediated decrease in the weight of accessory sex organs. Taken together, our findings clearly highlight the role of S. platensis as a protective modulator of HgCl2

  1. The fifth dimension of the taste in Spirulina platensis feed. Study on the influence of monosodium glutamate in the development and composition of the Spirulina platensis algae

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    Ştefan MANEA

    2010-12-01

    Full Text Available Food additives have become a way of life, creating pleasure and food request. But from the point of view of health promotion, it is necessary to demonstrate the risks and find out new possibilities for a good sensorial aspect of the food. This would apply especially in the case of long-term consumption, or in some particular conditions (allergies to different ingredients which appear more often to consumers. Cheap products are manufactured by using E-dangerous. The explanation is simple: the natural E extracted from various fruits and vegetables are very expensive. The study wants to demonstrate that the monosodium glutamate (MSG into the culture medium of plantscan affect their healthiness. Spirulina platensis has the same type of amino acids as humans and this is why it has been chosen as an experiment plant. Four samples obtained from the Spirulina’s culturemedium were studied: one blank and three with 0.2%, 0.4% and respectively 0.6% MSG in the culture medium. The mineral content was evaluated using the Atomic Absorption Spectroscopy (AAS and a rapid increase of calcium and magnesium content was registered for the sample with the biggest amount of MSG. The structure of the filaments and the cells appearance were evaluated microscopically. There were changes identified in the structure after three days of cultivating. Also, the sample with 0.6% MSG presented dead cells and the ones which were still alive had profound changes in form and structure.

  2. Dinâmica populacional de Aegla platensis Schmitt (Crustácea, Decapoda, Aeglidae Population's dynaniics of Aegla platensis Schmitt (Crustácea, Decapoda, Aeglidae

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    Alessandra Angélica de Pádua Bueno

    2000-03-01

    Full Text Available The crustaceans of the genus Aegla Leach, 1820, are found in streams, rivers of caves, current rivers and lagoons, from Franca, São Paulo, Brazil (20º60'S, 47º40'W, to Ilha Madre de Dios (5uº01'10"S, 75º18'45"W, Chile in South America. The crabs (Aegla plalensis Schmitt, 1942 were monthly sampled by hand fromjuly 1997 to september 1998 in Arroio do Mineiro, Taquara (29º46'S, 50º53'W, Rio Grande do Sul, Brazil. The sex, the length and width of the carapace were registered. After being collected the animais were returned to the stream. The repro-ductive period, the size at the first maturation and the sex-ratio were identifred. The reproductive period of A. platensis lasts the whole year. The percentage of ovigerous females is higher in july. The size at the first maturation is from 14,40 to 15,60 mm of carapace length. The sex-ratio is 1,08 male to 1 female. The annual population's density is 12 animais per square meter.

  3. Supplementation of Spirulina (Arthrospira platensis) Improves Lifespan and Locomotor Activity in Paraquat-Sensitive DJ-1β(Δ93) Flies, a Parkinson's Disease Model in Drosophila melanogaster.

    Science.gov (United States)

    Kumar, Ajay; Christian, Pearl K; Panchal, Komal; Guruprasad, B R; Tiwari, Anand K

    2017-09-03

    Spirulina (Arthrospira platensis) is a cyanobacterium (blue-green alga) consumed by humans and other animals because of its nutritional values and pharmacological properties. Apart from high protein contents, it also contains high levels of antioxidant and anti-inflammatory compounds, such as carotenoids, β-carotene, phycocyanin, and phycocyanobilin, indicating its possible pharmaco-therapeutic utility. In the present study using DJ-1β(Δ93) flies, a Parkinson's disease model in Drosophila, we have demonstrated the therapeutic effect of spirulina and its active component C-phycocyanin (C-PC) in the improvement of lifespan and locomotor behavior. Our findings indicate that dietary supplementation of spirulina significantly improves the lifespan and locomotor activity of paraquat-fed DJ-1β(Δ93) flies. Furthermore, supplementation of spirulina and C-PC individually and independently reduced the cellular stress marked by deregulating the expression of heat shock protein 70 and Jun-N-terminal kinase signaling in DJ-1β(Δ93) flies. A significant decrease in superoxide dismutase and catalase activities in spirulina-fed DJ-1β(Δ93) flies tends to indicate the involvement of antioxidant properties associated with spirulina in the modulation of stress-induced signaling and improvement in lifespan and locomotor activity in Drosophila DJ-1β(Δ93) flies. Our results suggest that antioxidant boosting properties of spirulina can be used as a nutritional supplement for improving the lifespan and locomotor behavior in Parkinson's disease.

  4. Hallazgo de Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae en el estado brasileño de "Rio Grande do Sul" Finding of Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae in the Brazilian State of "Rio Grande do Sul"

    Directory of Open Access Journals (Sweden)

    Roberto Salvatella

    1991-02-01

    Full Text Available Triatoma platensis Neiva 1913 (Hemiptera, Triatominae, especie ornitófila, con área de dispersión conocida en Argentina, Bolivia, Paraguay y Uruguay es notificada en un primer registro para Brasil. Hallada en el municipio de Uruguaiana (Río Grande do Sul en nidos de Anumbius annumbi (Vieillot, 1817 (Passeriformes, Furnariidae donde cohabitaba con cricétidos de la especie Orizomys flavescens. Ningún ejemplar de los siete colectados se presentó infectado por Trypanosoma cruzi.Triatoma platensis, an ornitophilic species, found in Argentina, Bolivia, Paraguay and Uruguay is reported for the first time in Brazil. It was found in the county of Uruguaiana (Rio Grande do Sul in nests of Anumbius annumbi (Vieillot, 1817 (Passeriformes, Furnariidae where it cohabited with cricetids belonging to the species Orizomys flavescens. None of the seven individuals collected were infected by Trypanosoma cruzi.

  5. Inhibitory effects of small molecular peptides from Spirulina (Arthrospira) platensis on cancer cell growth.

    Science.gov (United States)

    Wang, Zhujun; Zhang, Xuewu

    2016-02-01

    In this study, the whole proteins of Spirulina (Arthrospira) platensis were extracted, hydrolysis with three proteases (trypsin, alcalase and papain) was performed, and gel filtration chromatography was employed to separate hydrolysates. Totally, 15 polypeptides were isolated, which showed anti-proliferation activities on five cancer cells (HepG-2, MCF-7, SGC-7901, A549 and HT-29), with the IC50 values between <31.25 and 336.57 μg mL(-1). Moreover, a new peptide YGFVMPRSGLWFR was identified from papain-digested hydrolysates. It also exhibited inhibitory activities on cancer cells, and the best activity was observed on A549 cancer cells (IC50 values 104.05 μg mL(-1)). In other words, these polypeptides exhibited anti-proliferation activities on cancer cells, and low toxicity or stimulatory activity on normal cells, suggesting that they are promising ingredients in food and pharmaceutical applications.

  6. Protective Role of Spirulina platensis against Acute Deltamethrin-Induced Toxicity in Rats

    Science.gov (United States)

    Abdel-Daim, Mohamed M.; Abuzead, Said M. M.; Halawa, Safaa M.

    2013-01-01

    Deltamethrin is a broad-spectrum synthetic pyrethroid insecticide and acaricide widely used for agricultural and veterinary purposes. However, its human and animal exposure leads to hepatonephrotoxicity. Therefore, the present study was undertaken to examine the hepatonephroprotective and antioxidant potential of Spirulina platensis against deltamethrin toxicity in male Wistar albino rats. Deltamethrin treated animals revealed a significant increase in serum biochemical parameters as well as hepatic and renal lipid peroxidation but caused an inhibition in antioxidant biomarkers. Spirulina normalized the elevated serum levels of AST, ALT, APL, uric acid, urea and creatinine. Furthermore, it reduced deltamethrin-induced lipid peroxidation and oxidative stress in a dose dependent manner. Therefore, it could be concluded that spirulina administration able to minimize the toxic effects of deltamethrin by its free radical-scavenging and potent antioxidant activity. PMID:24039839

  7. Studies on the proteins of mass-cultivated, blue-green alga (Spirulina platensis)

    Energy Technology Data Exchange (ETDEWEB)

    Annusuyadevi, M.; Subbulakshmi, G.; Madhair' devi, K.; Venkalaramein, L.V.

    1981-05-01

    The characteristics of the protein of fresh-water, mass-cultured Spirulina platensis have been studied. The solubility of this algal protein in water and various aqueous solvents has been estimated. The total protein content of the blue-green algae was approximately 50-55% of which nearly 9.9% was nonprotein nitrogen. About 80% of the total protein nitrogen can be extracted by three successive extractions with water. Ths isoelectric point of this algal protein is found to be 3.0. The total proteins were characterized physicochemically by standard techniques. In the ultracentrifuge total proteins resolve into two major components with S20w values of 2.6 and 4.7 S. The polyacrylamide gel electrophoretic pattern of the total protein showed seven bands including three prominent ones. The in vitro digestibility of the total protein of fresh algae was found to be 85% when assayed with a pepsin-pancreatin system.

  8. Experimental and modelling of Arthrospira platensis cultivation in open raceway ponds.

    Science.gov (United States)

    Ranganathan, Panneerselvam; Amal, J C; Savithri, S; Haridas, Ajith

    2017-10-01

    In this study, the growth of Arthrospira platensis was studied in an open raceway pond. Furthermore, dynamic model for algae growth and CFD modelling of hydrodynamics in open raceway pond were developed. The dynamic behaviour of the algal system was developed by solving mass balance equations of various components, considering light intensity and gas-liquid mass transfer. A CFD modelling of the hydrodynamics of open raceway pond was developed by solving mass and momentum balance equations of the liquid medium. The prediction of algae concentration from the dynamic model was compared with the experimental data. The hydrodynamic behaviour of the open raceway pond was compared with the literature data for model validation. The model predictions match the experimental findings. Furthermore, the hydrodynamic behaviour and residence time distribution in our small raceway pond were predicted. These models can serve as a tool to assess the pond performance criteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Impact of natural light on growth and biopigment profile of cyanobacteria Spirulina platensis.

    Science.gov (United States)

    Sharma, Gaurav; Kumar, Manoj; Ali, Mohammad Irfan; Saran, Suman; Jasuja, Nakuleshwar Dut

    2015-11-01

    Cyanobacteria are economically important microorganisms and good source of natural pigments such as chlorophyll, carotenoids and phycobilliproteins. The present research work showed the optimum combination of photophase and scotophase of Spirulina platensis on biomass and chlorophyll-a, carotenoids, phycocyanin, allophycocyanin, and phycoerythrin contents. The study revealed that among all six light conditions tested, the cultures placed at west facing window, receiving natural day light at temperature 30°C showed extremely significant higher biomass (O.D. 3.46 ± 0.17%) and biopigment accumulation Chlorophyll a 8.94 ± 0.43%, Carotenoid 1.62 ± 0.18%, phycocyanin 2.26 ± 0.14%, allophycocyanin 2.66 ± 0.18% and phycoerythrin 1.32 ± 0.31% as compared to the standard (Full day natural light), which might be beneficial for large scale production of biopigment.

  10. Calcium spirulan, an inhibitor of enveloped virus replication, from a blue-green alga Spirulina platensis.

    Science.gov (United States)

    Hayashi, T; Hayashi, K; Maeda, M; Kojima, I

    1996-01-01

    Bioactivity-directed fractionation of a hot H2O extract from a blue-green alga Spirulina platensis led to the isolation of a novel sulfated polysaccharide named calcium spirulan (Ca-SP) as an antiviral principle. This polysaccharide was composed of rhamnose, ribose, mannose, fructose, galactose, xylose, glucose, glucuronic acid, galacturonic acid, sulfate, and calcium. Ca-SP was found to inhibit the replication of several enveloped viruses, including Herpes simplex virus type 1, human cytomegalovirus, measles virus, mumps virus, influenza A virus, and HIV-1. It was revealed that Ca-SP selectively inhibited the penetration of virus into host cells. Retention of molecular conformation by chelation of calcium ion with sulfate groups was suggested to be indispensable to its antiviral effect.

  11. Study on the Structure of C-Phycocyanin in Spirulina platensis with Scanning Tunneling Microscope.

    Science.gov (United States)

    Zhang, Yu-Zhong; Shi, Dong-Xia; Zhou, Bai-Cheng; Zeng, Cheng-Kui; Pang, Shi-Jin

    1997-01-01

    The C-phycocyanin (C-PC) trimmer was isolated from the blue-green alga Spirulina platensis, and scanning tunneling microscope (STM) was used to investigate its structure. High resolution STM images of C-PC were obtained. From the STM images, it could be observed that the C-PC molecules were disk-like in shape and the subunits of C-PC arranged in ring-like pattern with a channel in the center. After filter treatment, the folding of the polypeptide chains could be seen clearly. This is the first time to observe directly the topography of phycobiliprotein, and the results showed STM to be a powerful tool for the structural study of phycobiliproteins.

  12. Proteomic analysis and qRT-PCR verification of temperature response to Arthrospira (Spirulina platensis.

    Directory of Open Access Journals (Sweden)

    Wang Huili

    Full Text Available Arthrospira (Spirulina platensis (ASP is a representative filamentous, non-N2-fixing cyanobacterium that has great potential to enhance the food supply and possesses several valuable physiological features. ASP tolerates high and low temperatures along with highly alkaline and salty environments, and can strongly resist oxidation and irradiation. Based on genomic sequencing of ASP, we compared the protein expression profiles of this organism under different temperature conditions (15°C, 35°Cand 45°C using 2-DE and peptide mass fingerprinting techniques. A total of 122 proteins having a significant differential expression response to temperature were retrieved. Of the positively expressed proteins, the homologies of 116 ASP proteins were found in Arthrospira (81 proteins in Arthrospira platensis str. Paraca and 35 in Arthrospira maxima CS-328. The other 6 proteins have high homology with other microorganisms. We classified the 122 differentially expressed positive proteins into 14 functions using the COG database, and characterized their respective KEGG metabolism pathways. The results demonstrated that these differentially expressed proteins are mainly involved in post-translational modification (protein turnover, chaperones, energy metabolism (photosynthesis, respiratory electron transport, translation (ribosomal structure and biogenesis and carbohydrate transport and metabolism. Others proteins were related to amino acid transport and metabolism, cell envelope biogenesis, coenzyme metabolism and signal transduction mechanisms. Results implied that these proteins can perform predictable roles in rendering ASP resistance against low and high temperatures. Subsequently, we determined the transcription level of 38 genes in vivo in response to temperature and identified them by qRT-PCR. We found that the 26 differentially expressed proteins, representing 68.4% of the total target genes, maintained consistency between transcription and

  13. Stable Isolation of Phycocyanin from Spirulina platensis Associated with High-Pressure Extraction Process

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    Kyung-Hwan Jung

    2013-01-01

    Full Text Available A method for stably purifying a functional dye, phycocyanin from Spirulina platensis was developed by a hexane extraction process combined with high pressure. This was necessary because this dye is known to be very unstable during normal extraction processes. The purification yield of this method was estimated as 10.2%, whose value is 3%–5% higher than is the case from another conventional separation method using phosphate buffer. The isolated phycocyanin from this process also showed the highest purity of 0.909 based on absorbance of 2.104 at 280 nm and 1.912 at 620 nm. Two subunits of phycocyanin namely α-phycocyanin (18.4 kDa and β-phycocyanin (21.3 kDa were found to remain from the original mixtures after being extracted, based on SDS-PAGE analysis, clearly demonstrating that this process can stably extract phycocyanin and is not affected by extraction solvent, temperature, etc. The stability of the extracted phycocyanin was also confirmed by comparing its DPPH (α,α-diphenyl-β-picrylhydrazyl scavenging activity, showing 83% removal of oxygen free radicals. This activity was about 15% higher than that of commercially available standard phycocyanin, which implies that the combined extraction method can yield relatively intact chromoprotein through absence of degradation. The results were achieved because the low temperature and high pressure extraction effectively disrupted the cell membrane of Spirulina platensis and degraded less the polypeptide subunits of phycocyanin (which is a temperature/pH-sensitive chromoprotein as well as increasing the extraction yield.

  14. Ethyl Formate: A Potential Disinfestation Treatment for Eucalyptus Weevil (Gonipterus platensis) (Coleoptera: Curculionidae) in Apples.

    Science.gov (United States)

    Agarwal, Manjree; Ren, Yonglin; Newman, James; Learmonth, Stewart

    2015-12-01

    Export of Pink Lady apples from Australia has been significantly affected by infestations of adult eucalyptus weevils (Gonipterus platensis Marelli). These weevils cling tenaciously to the pedicel of apple fruit when selecting overwintering sites. As a result, apples infested with live G. platensis adults lead to rejection for export. Since the Montreal Protocol restricted use of methyl bromide as postharvest treatment, it was necessary to consider alternative safer fumigants for disinfestation of eucalyptus weevil. Laboratory experiments were conducted using concentrations of 5, 10, 15, 20, 25, 30, 40, and 80 mg/liter of ethyl formate. Complete control (100% mortality) was achieved at 25-30 mg/liter of ethyl formate at 22-24°C for 24-h exposure without apples. However, with 90-95% of the volume full of apples, complete control was achieved at 40 mg/liter of ethyl formate at 22-24°C for 24-h exposure. No phytotoxicity was observed and after one day aeration, residue of ethyl formate declined to natural levels (0.05-0.2 mg/kg). Five ethyl formate field trials were conducted in cool storages (capacity from 250-900 tons) and 100% kill of eucalyptus weevils were achieved at 50-55 mg/liter at 7-10°C for 24 h. Ethyl formate has great potential for preshipment treatment of apples. Its use is considerably cheaper and safer than already existing fumigants like methyl bromide and phosphine.

  15. Proteomic analysis and qRT-PCR verification of temperature response to Arthrospira (Spirulina) platensis.

    Science.gov (United States)

    Huili, Wang; Xiaokai, Zhao; Meili, Lin; Dahlgren, Randy A; Wei, Chen; Jaiopeng, Zhou; Chengyang, Xu; Chunlei, Jin; Yi, Xu; Xuedong, Wang; Li, Ding; Qiyu, Bao

    2013-01-01

    Arthrospira (Spirulina) platensis (ASP) is a representative filamentous, non-N2-fixing cyanobacterium that has great potential to enhance the food supply and possesses several valuable physiological features. ASP tolerates high and low temperatures along with highly alkaline and salty environments, and can strongly resist oxidation and irradiation. Based on genomic sequencing of ASP, we compared the protein expression profiles of this organism under different temperature conditions (15°C, 35°Cand 45°C) using 2-DE and peptide mass fingerprinting techniques. A total of 122 proteins having a significant differential expression response to temperature were retrieved. Of the positively expressed proteins, the homologies of 116 ASP proteins were found in Arthrospira (81 proteins in Arthrospira platensis str. Paraca and 35 in Arthrospira maxima CS-328). The other 6 proteins have high homology with other microorganisms. We classified the 122 differentially expressed positive proteins into 14 functions using the COG database, and characterized their respective KEGG metabolism pathways. The results demonstrated that these differentially expressed proteins are mainly involved in post-translational modification (protein turnover, chaperones), energy metabolism (photosynthesis, respiratory electron transport), translation (ribosomal structure and biogenesis) and carbohydrate transport and metabolism. Others proteins were related to amino acid transport and metabolism, cell envelope biogenesis, coenzyme metabolism and signal transduction mechanisms. Results implied that these proteins can perform predictable roles in rendering ASP resistance against low and high temperatures. Subsequently, we determined the transcription level of 38 genes in vivo in response to temperature and identified them by qRT-PCR. We found that the 26 differentially expressed proteins, representing 68.4% of the total target genes, maintained consistency between transcription and translation levels. The

  16. Role of pH on antioxidants production by Spirulina (Arthrospira platensis

    Directory of Open Access Journals (Sweden)

    Mostafa Mahmoud Sami Ismaiel

    2016-06-01

    Full Text Available Abstract Algae can tolerate a broad range of growing conditions but extreme conditions may lead to the generation of highly dangerous reactive oxygen species (ROS, which may cause the deterioration of cell metabolism and damage cellular components. The antioxidants produced by algae alleviate the harmful effects of ROS. While the enhancement of antioxidant production in blue green algae under stress has been reported, the antioxidant response to changes in pH levels requires further investigation. This study presents the effect of pH changes on the antioxidant activity and productivity of the blue green alga Spirulina (Arthrospira platensis. The algal dry weight (DW was greatly enhanced at pH 9.0. The highest content of chlorophyll a and carotenoids (10.6 and 2.4 mg/g DW, respectively was recorded at pH 8.5. The highest phenolic content (12.1 mg gallic acid equivalent (GAE/g DW was recorded at pH 9.5. The maximum production of total phycobiliprotein (159 mg/g DW was obtained at pH 9.0. The antioxidant activities of radical scavenging activity, reducing power and chelating activity were highest at pH 9.0 with an increase of 567, 250 and 206% compared to the positive control, respectively. Variation in the activity of the antioxidant enzymes superoxide dismutase (SOD, catalase (CAT and peroxidase (POD was also reported. While the high alkaline pH may favor the overproduction of antioxidants, normal cell metabolism and membrane function is unaffected, as shown by growth and chlorophyll content, which suggests that these conditions are suitable for further studies on the harvest of antioxidants from S. platensis.

  17. Proteomic Analysis and qRT-PCR Verification of Temperature Response to Arthrospira (Spirulina) platensis

    Science.gov (United States)

    Huili, Wang; Xiaokai, Zhao; Meili, Lin; Dahlgren, Randy A.; Wei, Chen; Jaiopeng, Zhou; Chengyang, Xu; Chunlei, Jin; Yi, Xu; Xuedong, Wang; Li, Ding; Qiyu, Bao

    2013-01-01

    Arthrospira (Spirulina) platensis (ASP) is a representative filamentous, non-N2-fixing cyanobacterium that has great potential to enhance the food supply and possesses several valuable physiological features. ASP tolerates high and low temperatures along with highly alkaline and salty environments, and can strongly resist oxidation and irradiation. Based on genomic sequencing of ASP, we compared the protein expression profiles of this organism under different temperature conditions (15°C, 35°Cand 45°C) using 2-DE and peptide mass fingerprinting techniques. A total of 122 proteins having a significant differential expression response to temperature were retrieved. Of the positively expressed proteins, the homologies of 116 ASP proteins were found in Arthrospira (81 proteins in Arthrospira platensis str. Paraca and 35 in Arthrospira maxima CS-328). The other 6 proteins have high homology with other microorganisms. We classified the 122 differentially expressed positive proteins into 14 functions using the COG database, and characterized their respective KEGG metabolism pathways. The results demonstrated that these differentially expressed proteins are mainly involved in post-translational modification (protein turnover, chaperones), energy metabolism (photosynthesis, respiratory electron transport), translation (ribosomal structure and biogenesis) and carbohydrate transport and metabolism. Others proteins were related to amino acid transport and metabolism, cell envelope biogenesis, coenzyme metabolism and signal transduction mechanisms. Results implied that these proteins can perform predictable roles in rendering ASP resistance against low and high temperatures. Subsequently, we determined the transcription level of 38 genes in vivo in response to temperature and identified them by qRT-PCR. We found that the 26 differentially expressed proteins, representing 68.4% of the total target genes, maintained consistency between transcription and translation levels. The

  18. Thermal and photo-stability of the antioxidant potential of Spirulina platensis powder.

    Science.gov (United States)

    Colla, L M; Bertol, C D; Ferreira, D J; Bavaresco, J; Costa, J A V; Bertolin, T E

    2016-09-26

    This work aimed to evaluate the thermal and photo stability of the antioxidant potential (AP) of the Spirulina platensis biomass. Thermal stability was established at 25ºC, 40ºC and 50ºC for 60 days, in the dark, protected from light. Photo stability was evaluated using UV (15 W, λ = 265 nm) and fluorescent (20 W, 0.16 A, power factor FP > 0.5, 50/60 Hz, 60 lm/w, 1200 lm) light for 90 days in capsules, glass and Petri dishes, at room temperature. The AP of the biomass in these conditions was determined at intervals (every 7 and 30 days in the studies of thermal and photo stability, respectively) using the induction of the oxidation of a lipid system by heat and aeration. In this lipid system, the biomass submitted to degradation was used as an antioxidant. The kinetics of the reaction was determined by the Arrhenius method. Thermal degradation was found to follow zero order kinetics, whereas photo degradation followed first order kinetics. The AP decreased 50% after 50 days at 25°C. At 40°C and 50°C, the AP decreased more than 50% after 35 and 21 days of exposition, respectively. The decrease of the AP of Spirulina was more sensible to UV and fluorescence light. After 30 days of exposition, the AP decreased more than 50% in all storage conditions tested. The antioxidant potential of Spirulina platensis is easily degraded when the biomass is exposed to heat and light, indicating the need for care to be taken in its storage.

  19. Stable Isolation of Phycocyanin from Spirulina platensis Associated with High-Pressure Extraction Process

    Science.gov (United States)

    Seo, Yong Chang; Choi, Woo Seok; Park, Jong Ho; Park, Jin Oh; Jung, Kyung-Hwan; Lee, Hyeon Yong

    2013-01-01

    A method for stably purifying a functional dye, phycocyanin from Spirulina platensis was developed by a hexane extraction process combined with high pressure. This was necessary because this dye is known to be very unstable during normal extraction processes. The purification yield of this method was estimated as 10.2%, whose value is 3%–5% higher than is the case from another conventional separation method using phosphate buffer. The isolated phycocyanin from this process also showed the highest purity of 0.909 based on absorbance of 2.104 at 280 nm and 1.912 at 620 nm. Two subunits of phycocyanin namely α-phycocyanin (18.4 kDa) and β-phycocyanin (21.3 kDa) were found to remain from the original mixtures after being extracted, based on SDS-PAGE analysis, clearly demonstrating that this process can stably extract phycocyanin and is not affected by extraction solvent, temperature, etc. The stability of the extracted phycocyanin was also confirmed by comparing its DPPH (α,α-diphenyl-β-picrylhydrazyl) scavenging activity, showing 83% removal of oxygen free radicals. This activity was about 15% higher than that of commercially available standard phycocyanin, which implies that the combined extraction method can yield relatively intact chromoprotein through absence of degradation. The results were achieved because the low temperature and high pressure extraction effectively disrupted the cell membrane of Spirulina platensis and degraded less the polypeptide subunits of phycocyanin (which is a temperature/pH-sensitive chromoprotein) as well as increasing the extraction yield. PMID:23325046

  20. Supercritical Carbon Dioxide and Microwave-Assisted Extraction of Functional Lipophilic Compounds from Arthrospira platensis

    Directory of Open Access Journals (Sweden)

    Diego A. Esquivel-Hernández

    2016-05-01

    Full Text Available Arthrospira platensis biomass was used in order to obtain functional lipophilic compounds through green extraction technologies such as supercritical carbon dioxide fluid extraction (SFE and microwave-assisted extraction (MAE. The temperature (T factor was evaluated for MAE, while for SFE, pressure (P, temperature (T, and co-solvent (ethanol (CS were evaluated. The maximum extraction yield of the obtained oleoresin was (4.07% ± 0.14% and (4.27% ± 0.10% for SFE and MAE, respectively. Extracts were characterized by gas chromatography mass spectrometry (GC-MS and gas chromatography flame ionization detector (GC-FID. The maximum contents of functional lipophilic compounds in the SFE and MAE extracts were: for carotenoids 283 ± 0.10 μg/g and 629 ± 0.13 μg/g, respectively; for tocopherols 5.01 ± 0.05 μg/g and 2.46 ± 0.09 μg/g, respectively; and for fatty acids 34.76 ± 0.08 mg/g and 15.88 ± 0.06 mg/g, respectively. In conclusion, the SFE process at P 450 bar, T 60 °C and CS 53.33% of CO2 produced the highest yield of tocopherols, carotenoids and fatty acids. The MAE process at 400 W and 50 °C gives the best extracts in terms of tocopherols and carotenoids. For yield and fatty acids, the MAE process at 400 W and 70 °C produced the highest values. Both SFE and MAE showed to be suitable green extraction technologies for obtaining functional lipophilic compounds from Arthrospira platensis.

  1. Supercritical Carbon Dioxide and Microwave-Assisted Extraction of Functional Lipophilic Compounds from Arthrospira platensis

    Science.gov (United States)

    Esquivel-Hernández, Diego A.; López, Víctor H.; Rodríguez-Rodríguez, José; Alemán-Nava, Gibrán S.; Cuéllar-Bermúdez, Sara P.; Rostro-Alanis, Magdalena; Parra-Saldívar, Roberto

    2016-01-01

    Arthrospira platensis biomass was used in order to obtain functional lipophilic compounds through green extraction technologies such as supercritical carbon dioxide fluid extraction (SFE) and microwave-assisted extraction (MAE). The temperature (T) factor was evaluated for MAE, while for SFE, pressure (P), temperature (T), and co-solvent (ethanol) (CS) were evaluated. The maximum extraction yield of the obtained oleoresin was (4.07% ± 0.14%) and (4.27% ± 0.10%) for SFE and MAE, respectively. Extracts were characterized by gas chromatography mass spectrometry (GC-MS) and gas chromatography flame ionization detector (GC-FID). The maximum contents of functional lipophilic compounds in the SFE and MAE extracts were: for carotenoids 283 ± 0.10 μg/g and 629 ± 0.13 μg/g, respectively; for tocopherols 5.01 ± 0.05 μg/g and 2.46 ± 0.09 μg/g, respectively; and for fatty acids 34.76 ± 0.08 mg/g and 15.88 ± 0.06 mg/g, respectively. In conclusion, the SFE process at P 450 bar, T 60 °C and CS 53.33% of CO2 produced the highest yield of tocopherols, carotenoids and fatty acids. The MAE process at 400 W and 50 °C gives the best extracts in terms of tocopherols and carotenoids. For yield and fatty acids, the MAE process at 400 W and 70 °C produced the highest values. Both SFE and MAE showed to be suitable green extraction technologies for obtaining functional lipophilic compounds from Arthrospira platensis. PMID:27164081

  2. Role of pH on antioxidants production by Spirulina (Arthrospira) platensis.

    Science.gov (United States)

    Ismaiel, Mostafa Mahmoud Sami; El-Ayouty, Yassin Mahmoud; Piercey-Normore, Michele

    2016-01-01

    Algae can tolerate a broad range of growing conditions but extreme conditions may lead to the generation of highly dangerous reactive oxygen species (ROS), which may cause the deterioration of cell metabolism and damage cellular components. The antioxidants produced by algae alleviate the harmful effects of ROS. While the enhancement of antioxidant production in blue green algae under stress has been reported, the antioxidant response to changes in pH levels requires further investigation. This study presents the effect of pH changes on the antioxidant activity and productivity of the blue green alga Spirulina (Arthrospira) platensis. The algal dry weight (DW) was greatly enhanced at pH 9.0. The highest content of chlorophyll a and carotenoids (10.6 and 2.4mg/g DW, respectively) was recorded at pH 8.5. The highest phenolic content (12.1mg gallic acid equivalent (GAE)/g DW) was recorded at pH 9.5. The maximum production of total phycobiliprotein (159mg/g DW) was obtained at pH 9.0. The antioxidant activities of radical scavenging activity, reducing power and chelating activity were highest at pH 9.0 with an increase of 567, 250 and 206% compared to the positive control, respectively. Variation in the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) was also reported. While the high alkaline pH may favor the overproduction of antioxidants, normal cell metabolism and membrane function is unaffected, as shown by growth and chlorophyll content, which suggests that these conditions are suitable for further studies on the harvest of antioxidants from S. platensis. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  3. Cultivation of Arthrospira (Spirulina platensis using confectionary wastes for aquaculture feeding

    Directory of Open Access Journals (Sweden)

    Hala Y. El-Kassas

    2015-12-01

    Full Text Available The microalga biomass production from confectionary effluent is a possible solution for the urgent need for a live food in aquaculture. Arthrospira (Spirulina platensis was the dominant alga in effluent of “Biscomisr a confectionary factory”, in Alexandria–Egypt. Therefore, it was isolated from the effluent samples and used throughout the study. The cyanobacterium, A. platensis was grown on the effluent using 22 Central Composite Design (22 CCD. This work addresses the best effluent dilution (WC, % as well as sodium bicarbonate concentration (SBC on the alga growth and biochemical composition. Total protein, carbohydrate, lipid contents and fatty acid profiles of the produced algal biomass were highly improved. The statistical analyses suggested that the main effect of (WC, % is significant negative influences on the algal contents of proteins, lipids and carbohydrates (p > 0.01. Although it had a significant positive influence on chlorophyll (p > 0.01, no significant effect on algal β carotenes (p > 0.05 had been reported. The inter action effect of SBC together with WC, % exerted a significant negative influence on the algal proteins (p > 0.01 and no significant effect on the other responses (p > 0.05. The produced alga biomass was used for feeding the rotifer, Brachionus plicatilis for further application in aquaculture. Growth rate, reproductive rate and fecundity attributes, fatty acid content of B. plicatilis were amended. The Pearson correlation test indicated that β carotenes displayed a highly positive significant correlation with the growth rate of B. plicatilis (r = 0.733, p < 0.01 and the carbohydrates showed significant positive correlations with Egg % (r = 0.657, p < 0.05.

  4. Effects of dietary Spirulina platensis on growth performance, humoral and mucosal immune responses and disease resistance in juvenile great sturgeon (Huso huso Linnaeus, 1754).

    Science.gov (United States)

    Adel, Milad; Yeganeh, Sakineh; Dadar, Maryam; Sakai, Masahiro; Dawood, Mahmoud A O

    2016-09-01

    Dietary supplementation of Spirulina platensis at different levels (0% control, 2.5%, 5% and 10%) was evaluated to find out the effects on growth performance, digestive enzyme activities, humoral and skin innate immune responses and disease resistance in the great sturgeon (Huso huso). After 8 weeks of experimental trial, growth parameters, intestinal lactic acid bacteria count, protease and lipase activities were significantly high in 10% S. platensis fed group (P < 0.05). Similarly, in this group, respiratory burst activity of leucocytes and total protein of serum were also significantly high. Furthermore, supplementation of S. platensis at 5 or 10% exhibited higher serum IgM and lysozyme activity than the other experimental groups (P < 0.05). On the contrary, serum triglycerides and number of blood lymphocytes were lower in experimental groups than that of control group. Total proteins, lysozyme, protease and esterase, as well as in vitro bactericidal activity (against Streptococcus iniae, Yersinia ruckeri, Aeromonas hydrophila and Lactococcus garviea) were significantly high in skin mucus from fish fed 5% and 10% S. platensis, while, alkaline phosphatase was significantly high in fish fed 10% S. platensis (P < 0.05). Further, fish infected with Streptococcus iniae bacteria increased mortality, but it was alleviated by a diet supplemented with S. platensis. The present results demonstrate that this dietary supplementation with S. platensis (mainly at 10% level) could be useful for maintaining the overall health status of great sturgeon.

  5. Uptake of uranyl ions from uranium ores and sludges by means of Spirulina platensis, Porphyridium cruentum and Nostok linckia alga.

    Science.gov (United States)

    Cecal, Alexandru; Humelnicu, Doina; Rudic, Valeriu; Cepoi, Liliana; Ganju, Dumitru; Cojocari, Angela

    2012-08-01

    In this paper was studied the uranyl ions biosorption on three types of alga: Nostok linckia, Porphyridium cruentum and Spirulina platensis. These ions were supplied either from a pure solution of uranyl nitrate, or after leaching process of uranium ore, or from the sludge resulting in the output of pure UO(2) technology. It was investigated the retention degree versus contact time and afterwards the Langmuir and Freundlich biosorption isotherms of uranyl ions on the three alga types. The retention of UO(2)(2+) ions on alga was proved through FTIR spectra plotted before and after biosorption processes. From the experimental data it was found that regardless of origin of uranyl ions, the retention degree on alga decreased in the series. Spirulina platensis > Porphyridium cruentum ≥ Nostok linckia.

  6. Improved Performance of the Piezoelectric Monomorph with Perpendicular Electrode Connections for Sensing and Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Ming Ma

    2013-01-01

    Full Text Available Piezoelectric monomorph, which has only one element, is a potential structure for piezoelectric applications in some extreme conditions. But as the restriction of the strain neutral layer, the traditional parallel electrode connection is not effective for sensing and energy harvesting. In this paper, perpendicular electrode connections were designed to utilize the nonuniform shear piezoelectric effect in the cross section of the monomorph, which made the monomorph avoid the restriction of the strain neutral layer. The PZT5 ceramic monomorph was preliminarily studied in this experiment. By comparing seven forms of perpendicular electrode connections with the traditional parallel electrode connection, the whole superposed perpendicular electrode connection is considered as the optimal output way for the monomorph. It can produce 13 V peak-to-peak (pk-pk voltage in open circuit and 14.56 μW maximum power with the matching resistance, which are much more than the parallel electrode connection 0.78 V and 0.14 μW.

  7. Thermally robust Mo/CoFeB/MgO trilayers with strong perpendicular magnetic anisotropy.

    Science.gov (United States)

    Liu, T; Zhang, Y; Cai, J W; Pan, H Y

    2014-07-31

    The recent discovery of perpendicular magnetic anisotropy (PMA) at the CoFeB/MgO interface has accelerated the development of next generation high-density non-volatile memories by utilizing perpendicular magnetic tunnel junctions (p-MTJs). However, the insufficient interfacial PMA in the typical Ta/CoFeB/MgO system will not only complicate the p-MTJ optimization, but also limit the device density scalability. Moreover, the rapid decreases of PMA in Ta/CoFeB/MgO films with annealing temperature higher than 300°C will make the compatibility with CMOS integrated circuits a big problem. By replacing the Ta buffer layer with a thin Mo film, we have increased the PMA in the Ta/CoFeB/MgO structure by 20%. More importantly, the thermal stability of the perpendicularly magnetized (001)CoFeB/MgO films is greatly increased from 300°C to 425°C, making the Mo/CoFeB/MgO films attractive for a practical p-MTJ application.

  8. Removal of Nitrate and Phosphate from Municipal Wastewater Sludge by Chlorella vulgaris, Spirulina platensis and Scenedesmus quadricauda

    OpenAIRE

    Jalal K.C.A; Md Zahangir Alam; Matin W. A.; Kamaruzzaman B. Y.; Akbar J.; and Tofazzel Hossain

    2011-01-01

    Nitrate and phosphorus in wastewater contribute to health and environmental threats as they are linked to illnesses as well as ecosystem disruption via algal blooms in contaminated water bodies. Based on above perspectives a comparative study was conducted on three local freshwater microalgae:Chlorella vulgaris, Spirulina platensis and Scenedesmus quadricauda to evaluate their effects on nitrate and phosphorus removal from municipal wastewater sludge (MWS). Algae performance in removing nitra...

  9. Antioxidant and Angiostatic Effect of Spirulina platensis Suspension in Complete Freund’s Adjuvant-Induced Arthritis in Rats

    OpenAIRE

    Ali, Eman A. I.; Barakat, Bassant M.; Ranya Hassan

    2015-01-01

    Background Currently, natural products have built a well-recognized role in the management of many degenerative diseases, mainly rheumatoid arthritis. Recent studies suggest that Spirulina, a unicellular blue-green alga, may have a variety of health benefits and curative properties and is also competent of acting as an anti-inflammatory, antioxidant and recently anti-angiogenic agent. In the present study, the antioxidant and the immunomodulatory effect of Spirulina platensis as well as its a...

  10. Fabrication of electrodeposited Co nanowire arrays with perpendicular anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Ge Shihui E-mail: zhangzz@lzu.edu.cn; Ma Xiao; Li Chao; Li Wei

    2001-05-01

    Co nanowire arrays have been electrodeposited into polycarbonate membranes with nanosized pores at different voltages. By means of X-ray diffraction, electron diffraction, vibrating sample magnetometer, their microstructures and magnetic properties were investigated at full length. The sample prepared at -1.2 V, 250 mA/cm{sup 2} shows perpendicular anisotropy, but the one deposited at -1.0V, 125 mA/cm{sup 2} has no perpendicular anisotropy. This different magnetic behavior can be explained from their different microstructures. X-ray diffraction and electron diffraction evidence that the former sample is amorphous, and the latter is polycrystalline. In the polycrystalline sample, due to the competition of shape anisotropy and magnetocrystal anisotropy, the sample does not display perpendicular anisotropy. But magnetocrystal anisotropy is very small in amorphous sample, therefore, shape anisotropy plays a dominant role which leads to strong perpendicular anisotropy because of shape anisotropy. Furthermore, applying a magnetic field during deposition, Co grains will preferentially grow with c-axis along the wire axis, which also leads to strong perpendicular anisotropy.

  11. The interaction of turbulence with parallel and perpendicular shocks

    Science.gov (United States)

    Adhikari, L.; Zank, G. P.; Hunana, P.; Hu, Q.

    2016-11-01

    Interplanetary shocks exist in most astrophysical flows, and modify the properties of the background flow. We apply the Zank et al 2012 six coupled turbulence transport model equations to study the interaction of turbulence with parallel and perpendicular shock waves in the solar wind. We model the 1D structure of a stationary perpendicular or parallel shock wave using a hyperbolic tangent function and the Rankine-Hugoniot conditions. A reduced turbulence transport model (the 4-equation model) is applied to parallel and perpendicular shock waves, and solved using a 4th- order Runge Kutta method. We compare the model results with ACE spacecraft observations. We identify one quasi-parallel and one quasi-perpendicular event in the ACE spacecraft data sets, and compute various turbulent observed values such as the fluctuating magnetic and kinetic energy, the energy in forward and backward propagating modes, the total turbulent energy in the upstream and downstream of the shock. We also calculate the error associated with each turbulent observed value, and fit the observed values by a least square method and use a Fourier series fitting function. We find that the theoretical results are in reasonable agreement with observations. The energy in turbulent fluctuations is enhanced and the correlation length is approximately constant at the shock. Similarly, the normalized cross helicity increases across a perpendicular shock, and decreases across a parallel shock.

  12. Fed-batch strategy for enhancing cell growth and C-phycocyanin production of Arthrospira (Spirulina) platensis under phototrophic cultivation.

    Science.gov (United States)

    Xie, Youping; Jin, Yiwen; Zeng, Xianhai; Chen, Jianfeng; Lu, Yinghua; Jing, Keju

    2015-03-01

    The C-phycocyanin generated in blue-green algae Arthrospira platensis is gaining commercial interest due to its nutrition and healthcare value. In this study, the light intensity and initial biomass concentration were manipulated to improve cell growth and C-phycocyanin production of A.platensis in batch cultivation. The results show that low light intensity and high initial biomass concentration led to increased C-phycocyanin accumulation. The best C-phycocyanin productivity occurred when light intensity and initial biomass concentration were 300μmol/m(2)/s and 0.24g/L, respectively. The fed-batch cultivation proved to be an effective strategy to further enhance C-phycocyanin production of A.platensis. The results indicate that C-phycocyanin accumulation not only requires nitrogen-sufficient condition, but also needs other nutrients. The highest C-phycocyanin content (16.1%), production (1034mg/L) and productivity (94.8mg/L/d) were obtained when using fed-batch strategy with 5mM medium feeding. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Adaptation of light-harvesting systems of Arthrospira platensis to light conditions, probed by time-resolved fluorescence spectroscopy.

    Science.gov (United States)

    Akimoto, Seiji; Yokono, Makio; Hamada, Fumiya; Teshigahara, Ayaka; Aikawa, Shimpei; Kondo, Akihiko

    2012-08-01

    Cyanobacteria change the quantity and/or quality of their pigment-protein complexes in response to light conditions. In the present study, we analyzed excitation relaxation dynamics in the cyanobacterium, Arthrospira (Spirulina) platensis, grown under lights exhibiting different spectral profiles, by means of steady-state absorption and picosecond time-resolved fluorescence spectroscopies. It was found that F760, which is the PSI red-chlorophyll characteristic of A. platensis, contributes to slower energy-transfer phase in the PSI of A. platensis. Excitation energy transfers in phycobilisome and those from PSII to PSI were modified depending on the light quality. Existence of quencher was suggested in PSI of the blue-light grown cells. Phycobilisomes in the green-light grown cells and the far-red-light grown cells transferred excitation energy from phycobilisome to chlorophyll without loss of energy. In these cells, excitation energy was shared between two photosystems. Fast energy transfer was established in phycobilisome under the yellow-light condition where only the phycobilisome can absorb the cultivation light. Differences in light-harvesting and energy-transfer processes under different cultivation-light conditions are discussed. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.

  14. CoTaZr/Pd multilayer with perpendicular magnetic anisotropy

    Directory of Open Access Journals (Sweden)

    Yong Chang Lau

    2013-08-01

    Full Text Available We report a novel perpendicularly magnetized thin film [Co91.5Ta4.5Zr4/Pd]5 multilayer, which exhibits strong perpendicular magnetic anisotropy when grown on 5 nm of Pd and Ru seed layers. The Pd-seeded multilayer annealed at 300 °C shows an effective uniaxial anisotropy constant, Keff = 1.1 MJ m−3, with an anisotropy field as high as 1.6 T. The perpendicular anisotropy is sustained on annealing at 400 °C for 1 h. X-ray diffraction on multilayers with 30 repeats suggests that the use of amorphous CoTaZr reduces the stress of the stack, compared to [Co/Pd] multilayer.

  15. Perpendicular magnetic anisotropy of Co85Cr15/Pt multilayers

    Institute of Scientific and Technical Information of China (English)

    Pol Hwang; Baohe Li; Tao Yang; Zhonghai Zhai; Fengwu Zhu

    2004-01-01

    The CoCr/Pt bilayers and (CoCr/Pt)20 multilayers with Pt underlayer were prepared by DC magnetron sputtering. The effects of prepared condition on perpendicular magnetic anisotropy were investigated. The results show that the thickness of Pt underlayer has a great effect on the microstructure and perpendicular magnetic anisotropy of CoCr/Pt bilayers and (CoCr/Pt)20 multilayers.When the thickness of Pt underlayer increases, Pt(111) and CoCr(002) peaks of both CoCr/Pt bilayers and (CoCr/Pt)20 multilayers increase and the bilayer periodicity of the multilayers is improved. The effective magnetic anisotropy of (CoCr/Pt)20 multilayers with Pt underlayer was much larger than that of CoCr/Pt bilayers. The (CoCr/Pt)20 multilayers has a stronger perpendicular magnetic anisotropy than that of CoCr/Pt bilayers. This is ascribed to the interface magnetic anisotropy of the multilayers.

  16. Reduction of track width in perpendicular magnetic recording

    Science.gov (United States)

    Xia, W.; Yamada, T.; Aoi, H.; Muraoka, H.; Nakamura, Y.

    2005-02-01

    In order to three dimensionally analyze perpendicular magnetic recording mechanisms, we have developed a program in which the magnetization of magnetic particles is introduced into calculations of magnetization distributions in a recording layer, based on the commercial software JMAG-Studio. Because this program was based on a FEM calculation, the head and media interactions and demagnetization during the recording process can be accurately modeled. Using this program, methods to reduce the recorded track width in perpendicular magnetic recording were investigated. Decreasing the magnetic spacing, the use of a side-shielded head structure and using media with weak exchange coupling are effective ways to reduce the track width in a single pole head and double-layer perpendicular media recording system.

  17. NANO-MULTILAYERS WITH HIGH PERPENDICULAR ANISOTROPY FOR MAGNETIC RECORDING

    Institute of Scientific and Technical Information of China (English)

    T. Yang; B.H. Li; K. Kang; T. Suzuki

    2003-01-01

    (FePt/Ag)n nano-multilayers were deposited on MgO (100) single crystal with laser ablation and then subjected to annealing. FePt L1o grains with (001) texture and thus a large perpendicular magnetic anisotropy constant Ku of the order of 106J/m3 were formed. A thick Ag layer is found to be favorable for decreasing the dispersion of the easy axis for magnetization. The measurement of time decay of magnetization gave rise to a small activation volume of the order of 10-25 m3, showing the promising of being the recording medium for future high density perpendicular recording.

  18. Influence of desalinator wastewater for the cultivation of Arthrospira platensis. Fatty acids profile

    Directory of Open Access Journals (Sweden)

    Volkmann, Harriet

    2007-12-01

    Full Text Available The need for a desalination processes in northeastern Brazil is due to the salinity of its water sources. However, these processes produce residues with high saline concentrations and a significant environmental impact. These wastewaters can be used for Arthrospira platensis cultivation. This work aimed to cultivate Arthrospira platensis in three different media: Paoletti Synthetic Medium (PSM, Salinated Water Medium (SWM and Desalinator Wastewater Médium (DWWM. Microalgae were cultivated under controlled conditions, in 4 L photobioreactors, 30±1°C, 12 hours of light/dark photoperiod provided by fluorescent lamps at a light intensity of 140 μmol• m–2•s–1 and constant bubbling of air (0.5 L•L–1 •min–1. The effect of different media on cell concentration, productivity, total content of lipids and fatty acids profile was verified. Higher cell concentration, as well as higher productivity was observed in DWWM: 4.954 (±0.554 g•L–1 and 0.225 (±0.042 g•L–1 •day–1, respectively. Concerning total lipids, the contents of 4.54% and 4.69% were observed in DWWM and SWM, respectively. High levels of saturated fatty acids were observed in both treatments. Concerning γ-linolenic acid, the contents of 13.09% (DWWM and 11.95% (SWM were found.En la región nordeste de Brasil, debido a la elevada salinidad de los acuíferos, existe la necesidad de utilizar procesos de desalación. Sin embargo, estos procesos generan residuos con alta concentración salina, con significativo impacto ambiental. El objetivo de este trabajo fue el cultivo de Arthrospira platensis en tres medios de cultivo diferentes: medio de Paoletti, medio de agua salinizada y medio de agua de desecho obtenida en el proceso de desalación de acuíferos. Las microalgas fueron cultivadas en laboratorio, con condiciones controladas, en fotobiorreactores de 4 L, a 30±1°C y periodos de 12 horas de claridad/oscuridad con iluminación de 140 μmol•m–2•s–1 e

  19. Quantitative proteomics analysis by iTRAQ revealed underlying changes in thermotolerance of Arthrospira platensis.

    Science.gov (United States)

    Chang, Rong; Lv, Bingxin; Li, Bosheng

    2017-08-08

    Growth temperature is a critical factor that affects cultivation of Arthrospira platensis which is a type of cyanobacterium widely known as Spirulina that has significant commercial value. To investigate the molecular mechanism underlying the thermotolerance of Spirulina, differential protein expression profiling was carried out using iTRAQ-based quantitative proteomic analysis. This study only analyzed changes in thylakoids. Among the 2085 proteins quantified, 43 differentially expressed proteins were selected based on the fold change cutoff scores of ≥2 or ≤0.5 for up-regulation or down-regulation, respectively. An analysis of these 43 proteins found that 23% of them are photosynthetic system proteins which include photosynthetic enzymes and pigment proteins. The dynamic change of these proteins indicates that photosynthetic system functions were profoundly affected under heat stress and the light-dependent reactions were probably the most sensitive to temperature changes. Meanwhile, to cope with the low energy production due to impaired photosynthesis there was a considerable down-shift in protein synthesis which is a very energy demanding process. The impaired photosynthesis led to low energy generation that was compensated by a down-shift in translation (the most energy-demanding process) and an up-shift of glycolysis. The reduction of many ribosome proteins may lead to a loss in translation efficiency; therefore, Spirulina may adopted a different mechanism to increase translational elongation under heat stress to compensate for this loss, such as elevate L7/L12 proteins. Changes were also found in the classical heat shock proteins, the ROS scavenging system, DNA-binding proteins, and some membrane proteins. In conclusion, this research demonstrate that heat stress induces profound changes in cellular physiology and shed light on the mechanism of the heat stress response and thermotolerance of Arthrospira platensis. Arthrospira platensis, widely known as

  20. Reversal mechanism in perpendicular media with columnar structure

    NARCIS (Netherlands)

    Wielinga, T.; Lodder, J.C.

    1986-01-01

    A contribution is given to the discussion concerning the nature of the magnetization reversal process in sputtered CoCr recording media with columnar morphology. The paper is restricted to the additional effects on the total perpendicular anisotropy by studying the columnar shape anisotropy and the

  1. Quantum pumping in graphene with a perpendicular magnetic field

    NARCIS (Netherlands)

    Tiwari, R.P.; Blaauboer, M.

    2010-01-01

    We consider quantum pumping of Dirac fermions in a monolayer of graphene in the presence of a perpendicular magnetic field in the central pumping region. The two external pump parameters are electrical voltages applied to the graphene sheet on either side of the pumping region. We analyze this pump

  2. Quantitative magnetic force microscopy on perpendicularly magnetised samples

    NARCIS (Netherlands)

    Hug, Hans J.; Stiefel, B.; van Schendel, P.J.A.; Schendel, P.J.A.; Moser, A.; Hofer, R.; Martin, S.; Guntherodt, H.J.; Porthun, S.; Porthun, Steffen; Abelmann, Leon; Lodder, J.C.; Bochi, Gabriel; O'handley, R.C.

    1998-01-01

    We present a transfer-function approach to calculate the force on a magnetic force microscope tip and the stray field due to a perpendicularly magnetized medium having an arbitrary magnetization pattern. Under certain conditions, it is possible to calculate the magnetization pattern from the

  3. Pinning of written bits in perpendicular recording media

    Energy Technology Data Exchange (ETDEWEB)

    Greaves, S.J.; Muraoka, H. E-mail: muraoka@riec.tohoku.ac.jp; Sonobe, Y.; Schabes, M.; Nakamura, Y

    2001-10-01

    A perpendicular medium comprising two distinct magnetic layers is described. One layer has a granular structure with isolated, exchange-decoupled grains and the other is a continuous, exchange-coupled layer. In the combined structure domain wall movement is restricted and reversed grains within written bits are eliminated. The S/N ratio is improved compared with single layers of either type alone.

  4. SOILS, FERTILIZATION AND MANAGEMENT OF WATER Halotolerant/alkalophilic bacteria associated with the cyanobacterium Arthrospira platensis (Nordstedt Gomont that promote early growth in Sorghum bicolor (L. Moench

    Directory of Open Access Journals (Sweden)

    Liliana Gómez G

    2012-01-01

    Full Text Available Arthrospira platensis associated bacteria (APAB identified through molecuar biology like Bacillus okhensis, Indibacter alkaliphilus and Halomonas sp., are also producing 3-indol acetic acid (IAA, these bacteria was used in early plant growth promotion tests over Sorghum bicolor, these bioassay was considered indirect evidence to suggest that APAB also may have stimulatory effects over A. platensis growth naturally. I. alkaliphilus and B. okhensis enhanced early germination of S. bicolor seads, with better results than that achieved by Azospirillum brasilense, bacterium used like reference as a common plant growth promoting rizobacteria. The three APAB enhanced significative differences (P≤0.05 over morphoagronomic parameters, I. alkaliphilus and B. okhensis exhibith better resoults in elongation stimulation and root and foliage dry weight. Above evidence suggest this bacteria like plant growth promoting and it recomended testing with A. platensis axenic cultures and its associated bactteri for understanding true interaction between them.

  5. Induction of ovarian growth in Aegla platensis (Crustacea, Aeglidae by means of neuroregulators incorporated to food

    Directory of Open Access Journals (Sweden)

    Alejandra V Cahansky

    2008-09-01

    Full Text Available The freshwater crab Aegla platensis was used as a model to induce ovarian growth by adding different neuroregulators to a pellet food formulation. Added compounds were the dopaminergic inhibitor spiperone or the enkephalinergic inhibitor naloxone, both of them at a dose of 10-8 mol/animal. Animals were fed on the enriched pellets twice a week. After 7 wk, the gonadosomatic index (GI was calculated as (gonad fresh weight / body fresh weight x 100. GI significantly increased only for those females fed on spiperone pellets, compared to a control group receiving pellets with no compound added. During the assayed period, spiperone would be reverting the arrest exerted by dopamine on the neuroendocrine stimulation of ovarian growth. On the other hand, for both spiperone and naloxone a higher GI was correlated to a higher lipid content of both gonads and/or hepatopancreas, suggesting an increased energetic demand in accordance with an active investment in reproduction. Rev. Biol. Trop. 56 (3: 1201-1207. Epub 2008 September 30.Se utilizó al anomuro de agua dulce Aegla platensis como modelo para inducir el crecimiento ovárico mediante el agregado de diferentes neuroreguladores a una formulación de alimento pelleteado. Los compuestos agregados fueron el inhibidor dopaminergico spiperona ó el inhibidor encefalinérgico naloxone, ambos a una dosis de 10-8 moles/animal. Los animales fueron alimentados dos veces a la semana con pellets enriquecidos con alguno de los neuroreguladores. Luego de 7 semanas, se calculó el índice gonadomático (IG como (peso gonadal fresco/ peso corporal fresco x 100. El IG mostró un incremento significativamente sólo en aquellas hembras alimentadas con pellets enriquecidos con spiperona, en comparación con un grupo control que recibió pellets sin agregado alguno. Durante el período ensayado, la spiperona estaría revirtiendo el arresto ejercido por la dopamina sobre la estimulación neuroendocrina del crecimiento ov

  6. Fabrication of L1{sub 0}-MnAl perpendicularly magnetized thin films for perpendicular magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Hosoda, Masaki; Oogane, Mikihiko; Kubota, Miho; Saruyama, Haruaki; Iihama, Satoshi; Naganuma, Hiroshi; Ando, Yasuo [Department of Applied Physics, Graduate school of Engineering, Tohoku University, Aza-aoba 6-6-05, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Kubota, Takahide [WPI Advanced Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan)

    2012-04-01

    Structural and magnetic properties of MnAl thin films with different composition, growth temperature, and post-annealing temperature were investigated. The optimum condition for fabrication of L1{sub 0}-MnAl perpendicularly magnetized thin film deposited on Cr-buffered MgO single crystal substrate was revealed. The results of x ray diffraction indicated that the MnAl films annealed at proper temperature had a (001)-orientation and L1{sub 0}-ordered structure. The L1{sub 0}-ordered films were perpendicularly magnetized and had a large perpendicular anisotropy. In addition, low surface roughness was achieved. For the optimized fabrication condition, the saturation magnetization M{sub s} of 600 emu/cm{sup 3} and perpendicular magnetic anisotropy K{sub u} of 1.0 x 10{sup 7} erg/cm{sup 3} was obtained using the Mn{sub 48}Al{sub 52} target at deposition temperature of 200 deg. C and post-annealing temperature of 450 deg. C.

  7. Magnetoelastically induced perpendicular magnetic anisotropy and perpendicular exchange bias of CoO/CoPt multilayer films

    Science.gov (United States)

    Guo, Lei; Wang, Yue; Wang, Jian; Muraishi, Shinji; Sannomiya, Takumi; Nakamura, Yoshio; Shi, Ji

    2015-11-01

    The effects of magnetoelastically induced perpendicular magnetic anisotropy (PMA) on perpendicular exchange bias (PEB) have been studied in [CoO5nm/CoPt5nm]5 multilayer films. After deposition at room temperature, [CoO5nm/CoPt5nm]5 multilayer films were post-annealed at 100 °C, 250 °C, 300 °C and 375 °C for 3 h. In-plane tensile stress of CoPt layer was calculated by sin2 φ method, and we found it increased gradually upon annealing from 0.99 GPa (as-deposited) up to 3.02 GPa (300 °C-annealed). As to the magnetic property, significant enhancement of PMA was achieved in [CoO5nm/CoPt5nm]5 multilayer films after annealing due to the increase of CoPt layer in-plane tensile stress. With the enhancement of magnetoelastically induced PMA, great improvement of PEB was also achieved in [CoO5nm/CoPt5nm]5 multilayer films, which increased from 130 Oe (as-deposited) up to 1060 Oe (300 °C-annealed), showing the same change tendency as PMA and the strong correlation with CoPt layer in-plane tensile stress. We consider it is the increase of CoPt layer in-plane tensile stress that leads to the enhancement of CoPt layer PMA, which is favorable for the spins in CoPt layer aligning to a more perpendicular direction. And thus the enhanced PMA with more perpendicular spins alignment in CoPt layer results in the improved PEB in [CoO5nm/CoPt5nm]5 multilayer films through enhanced perpendicular spins coupling at CoO/CoPt interfaces.

  8. Langmuir-Blodgett Film of Phycobilisomes from Blue-Green Alga Spirulina platensis%钝顶螺旋藻(Spirulina platensis)藻胆体Langmuir-Blodgett膜

    Institute of Scientific and Technical Information of China (English)

    陈超; 张玉忠; 陈秀兰; 周百成; 高鸿钧

    2003-01-01

    The phycobilisomes were isolated from blue-green alga Spirulina platensis, and could form monolayer film at air/water interface. The monolayer film of phycobilisomes was transferred to newly cleaved mica, and coated with gold. Scanning tunneling microscope was used to investigate the structure of the Langmuir-Blodgett film of phycobilisomes. It was shown that phycobilisomes in the monolayer arrayed in rows with core attaching on the substrate surface and rods radiating towards the air phase, this phenomenon was similar to the arrangement of phycobilisomes on cytoplasmic surface of thylakoid membrane in vivo. The possible applications of the Langmuir-Blodgett film of phycobilisomes were also discussed.%从钝顶螺旋藻中分离制备完整藻胆体, 然后滴加于空气/水界面上, 应用LB膜技术制备藻胆体LB膜. 结果表明, 藻胆体在空气/水界面上具有很好的成膜性能. 将藻胆体LB单层膜转移到刚揭开的云母表面, 喷一层金, 然后用扫描隧道显微镜观察. 结果表明, 藻胆体在Langmuir-Blodgett膜中的排列方式与其在体内类囊体膜表面的排列方式类似, 一排排聚集在一起, 然后排列成膜. 藻胆体的"核"吸附在云母表面, 而藻胆体的"杆"伸向外面. 由于钝顶螺旋藻易于规模化培养, 藻胆体容易批量制备, 加之藻胆体具有的独特的光物理、光化学特性和良好的成膜性能, 以及本身就是纳米量级的颗粒(50~70 nm), 预示着藻胆体在纳米光电子器件中具有很好的应用前景.

  9. Kinetics and adsorption isotherm of C-phycocyanin from Spirulina platensis on ion-exchange resins

    Directory of Open Access Journals (Sweden)

    L. Sala

    2014-12-01

    Full Text Available C-phycocyanin is a natural blue dye extracted from Spirulina platensis, which has many applications in the food and pharmaceutical industries. In this paper the effect of pH and temperature on the adsorption of C-phycocyanin onto two different ion exchange resins (Streamline DEAE and Streamline Q XL for expanded bed adsorption chromatography was investigated. Moreover, the kinetics and adsorption isotherm were evaluated. The equilibrium for the Q XL matrix was reached after 60 min, while for DEAE it was only reached after 140 min. C-phycocyanin showed the highest partition coefficient at pH 7.5 for both resins at 25 ºC. The C-phycocyanin adsorption isotherm was very well represented by the Langmuir, Freundlich and Langmuir-Freundlich models, where the estimated values for Qm and Kd obtained by the Langmuir isotherm were, respectively, 33.92 mg.mL-1 and 0.123 mg.mL-1 for DEAE, and 28.12 mg.mL-1 and 0.082 mg.mL-1 for the Q XL matrix. A negative cooperativity was observed for C-phycocyanin binding when the Q XL matrix was used, while the cooperativity was purely independent using the DEAE matrix.

  10. A method to estimate the biomass of Spirulina platensis cultivated on a solid medium

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Pelizer

    2014-09-01

    Full Text Available This paper presents a method to estimate the biomass of Spirulina cultivated on solid medium with sugarcane bagasse as a support, in view of the difficulty in determining biomass concentrations in bioprocesses, particularly those conducted in semi-solid or solid media. The genus Spirulina of the family Oscillatoriaceae comprises the group of multicellular filamentous cyanobacteria (blue-green microalgae. Spirulina is used as fish feed in aquaculture, as a food supplement, a source of vitamins, pigments, antioxidants and fatty acids. Therefore, its growth parameters are extremely important in studies of the development and optimization of bioprocesses. For studies of biomass growth, Spirulina platensis was cultured on solid medium using sugarcane bagasse as a support. The biomass thus produced was estimated by determining the protein content of the material grown during the process, based on the ratio of dry weight to protein content obtained in the surface growth experiments. The protein content of the biomass grown in Erlenmeyer flasks on surface medium was examined daily to check the influence of culture time on the protein content of the biomass. The biomass showed an average protein content of 42.2%. This methodology enabled the concentration of biomass adhering to the sugarcane bagasse to be estimated from the indirect measurement of the protein content associated with cell growth.

  11. Protein production by Arthrospira (Spirulina platensis in solid state cultivation using sugarcane bagasse as support

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Pelizer

    2015-03-01

    Full Text Available The genus Arthrospira comprises a group of filamentous multicellular cyanobacteria and can be used for animal feed and human food. Solid state fermentation or cultivation (SSF involves the use of a culture medium composed of solid material with given moisture content. No studies have been published about the cultivation of microalgae or cyanobacteria on solid medium. Furthermore, although sugar-cane bagasse is used as source of energy in alcohol distilleries in Brazil, the excess could be a support to photosynthetic microorganism growth. The experimental design methodology was used to evaluate the protein production by Arthrospira platensis under SSF using sugarcane bagasse as support, taking into account the moisture content of the medium, light intensity and inoculum concentration. Moisture was found to have a strong influence on the performance of the process. The best conditions were: moisture of 98.8%; inoculum concentration of 0.15 g biomass·kg wet culture medium−1 and light intensity of 6.0 klx.

  12. Modulating Effects of Spirulina platensis against Tilmicosin-Induced Cardiotoxicity in Mice

    Directory of Open Access Journals (Sweden)

    Abdelaziz E. Ibrahim

    2015-04-01

    Full Text Available Objective: Tilmicosin (TIL is a long-acting macrolide antibiotic used to treat cattle for pathogens that cause bovine respiratory disease. However, overdoses of this medication have been reported to induce cardiac damage. Our experimental objective was to evaluate the protective effects of Spirulina platensis (SP administration against TIL-induced cardiotoxicity in mice. Materials and Methods: Our experimental in vivo animal study used 40 male albino mice that were divided into five groups of eight mice per group. The first group served as a control group and was injected with saline. The second group received SP at dose of 1000 mg/kg body weight for five days. The third group received a single dose of TIL (75 mg/kg, subcutaneously. Groups 4 and 5 were given SP at doses of 500 and 1000 mg/kg body weight for five consecutive days just before administration of TIL at the same dose and regimen used for group 3. Results: TIL treated animals showed a significant increase in serum cardiac injury biomarkers as well as cardiac lipid peroxidation, however they had evidence of an inhibition in antioxidant biomarkers. SP normalized elevated serum levels of lactate dehydrogenase (LDH, creatine kinase (CK, and CK-MB. Furthermore, SP reduced TIL-induced lipid peroxidation and oxidative stress in a dose-dependent manner. Conclusion: Administration of SP minimized the toxic effects of TIL by its free radicalscavenging and potent antioxidant activity.

  13. Ultra-sensitive conductometric detection of pesticides based on inhibition of esterase activity in Arthrospira platensis.

    Science.gov (United States)

    Tekaya, Nadèje; Saiapina, Olga; Ben Ouada, Hatem; Lagarde, Florence; Ben Ouada, Hafedh; Jaffrezic-Renault, Nicole

    2013-07-01

    Enzymatic conductometric biosensor, using immobilized Arthrospira platensis cells on gold interdigitated electrodes, for the detection of pesticides in water, was elaborated. Cholinesterase activity (AChE) was inhibited by pesticides and a variation of the local conductivity was measured after addition of the substrate acetylthiocholine chloride (AChCl). The Michaelis-Menten constant (Km) was evaluated to be 1.8 mM through a calibration curve of AChCl. Inhibition of AChE was observed with paraoxon-methyl, parathion-methyl, triazine and diuron with a detection limit of 10(-18) M, 10(-20) M, 10(-20) M and 10(-12) M, respectively and the half maximal inhibitory concentration (IC50) was determined at 10(-16) M, 10(-20) M, 10(-18) M and 10(-06) M, respectively. An important decrease of response time τ90% was recorded for AChE response towards AChCl after 30 min cell exposure to pesticides. Scanning electron microscopy images revealed a degradation of the cell surface in presence of pesticides at 10(-06) M.

  14. Probing the connection of PBSs to the photosystems in Spirulina platensis by artificially induced fluorescence fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Li Heng [Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Yang Shuzhen [Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Xie Jie [Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Zhao Jingquan [Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)]. E-mail: zhaojq@iccas.ac.cn

    2007-01-15

    The molecular architecture and the structural connections of phycobilisomes (PBSs) to the photosystems in the intact cells of Spirulina platensis were studied by taking advantage of glycerol- and betaine-induced fluorescence fluctuations. Generally, with a selective excitation of C-phycocyanin (C-PC), glycerol could induce not only decoupling of PBSs from the photosystems but also of C-PC rods from allophycocyanin (APC) cores, while betaine could strengthen the connection of PBSs to the thylakoid membrane but induce a partial dissociation of PBS. On the other hand, glycerol did not exert an influence on the fluorescence spectra of the photosystems in isolated thylakoid membrane. Therefore, it was deduced that glycerol could provide a molecular environment to weaken the hydrophobic interactions of not only the L{sub CM} with the membrane but also the linker polypeptides to the water-soluble phycobiliproteins (C-PC and APC), while the betaine could strengthen the hydrophobic interaction of L{sub CM} with the membrane but weaken the electrostatic interaction of linker polypeptides to C-PC and/or APC.

  15. Subcellular proteomic characterization of the high-temperature stress response of the cyanobacterium Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Cheevadhanarak Supapon

    2009-09-01

    Full Text Available Abstract The present study examined the changes in protein expression in Spirulina platensis upon exposure to high temperature, with the changes in expression analyzed at the subcellular level. In addition, the transcriptional expression level of some differentially expressed proteins, the expression pattern clustering, and the protein-protein interaction network were analyzed. The results obtained from differential expression analysis revealed up-regulation of proteins involved in two-component response systems, DNA damage and repair systems, molecular chaperones, known stress-related proteins, and proteins involved in other biological processes, such as capsule formation and unsaturated fatty acid biosynthesis. The clustering of all differentially expressed proteins in the three cellular compartments showed: (i the majority of the proteins in all fractions were sustained tolerance proteins, suggesting the roles of these proteins in the tolerance to high temperature stress, (ii the level of resistance proteins in the photosynthetic membrane was 2-fold higher than the level in two other fractions, correlating with the rapid inactivation of the photosynthetic system in response to high temperature. Subcellular communication among the three cellular compartments via protein-protein interactions was clearly shown by the PPI network analysis. Furthermore, this analysis also showed a connection between temperature stress and nitrogen and ammonia assimilation.

  16. Influence of ammonium chloride feeding time and light intensity on the cultivation of Spirulina (Arthrospira) platensis.

    Science.gov (United States)

    Bezerra, Raquel Pedrosa; Matsudo, Marcelo Chuei; Converti, Attilio; Sato, Sunao; de Carvalho, João Carlos Monteiro

    2008-06-01

    This study dealt with the influence of both the feeding time and light intensity on the fed-batch culture of the cyanobacterium Spirulina (Arthrospira) platensis using ammonium chloride as a nitrogen source. For this purpose, a 2(2) plus star central composite experimental design combined with response surface methodology was employed, and the maximum cell concentration (X(m)), the cell productivity (P(X)), and the yield of biomass on nitrogen (Y(X/N)) were selected as the response variables. The optimum values of X(m) (1,833 mg L(-1)) and Y(X/N) (5.9 g g(-1)) estimated by the model at light intensity of 13 klux and feeding time of 17.2 days were very close to those obtained experimentally under these conditions (X(m) = 1,771 +/- 41 mg L(-1); Y(X/N) = 5.7 +/- 0.17 g g(-1)). The cell productivity was a decreasing function of the ammonium chloride feeding time and a quadratic function of the light intensity. The protein and lipid contents of dry biomass collected at the end of cultivations were shown to decrease with increasing light intensity.

  17. Bioethanol Production by Carbohydrate-Enriched Biomass of Arthrospira (Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Dimitris Georgakakis

    2013-08-01

    Full Text Available In the present study the potential of bioethanol production using carbohydrate-enriched biomass of the cyanobacterium Arthrospira platensis was studied. For the saccharification of the carbohydrate-enriched biomass, four acids (H2SO4, HNO3, HCl and H3PO4 were investigated. Each acid were used at four concentrations, 2.5 N, 1 N, 0.5 N and 0.25 N, and for each acid concentration the saccharification was conducted under four temperatures (40 °C, 60 °C, 80 °C and 100 °C. Higher acid concentrations gave in general higher reducing sugars (RS yields (%, gRS/gTotal sugars with higher rates, while the increase in temperature lead to higher rates at lower acid concentration. The hydrolysates then were used as substrate for ethanolic fermentation by a salt stress-adapted Saccharomyces cerevisiae strain. The bioethanol yield (%, gEtOH/gBiomass was significantly affected by the acid concentration used for the saccharification of the carbohydrates. The highest bioethanol yields of 16.32% ± 0.90% (gEtOH/gBiomass and 16.27% ± 0.97% (gEtOH/gBiomass were obtained in hydrolysates produced with HNO3 0.5 N and H2SO4 0.5 N, respectively.

  18. Inf luence of Spirulina platensis exudates on the endocrine and nervous systems of a mammalian model

    Institute of Scientific and Technical Information of China (English)

    Samah; Mamdouh; Mohamed; Fathy; Ashraf; Mohamed; Mohamed; Essa

    2015-01-01

    Objective: To investigate the ef ect of intra-peritoneal injection of purii ed exudates of axenic Spirulina platensis on the mammalian endocrine and nervous systems. Methods: The intra-peritoneal injection of the cyanobacterial exudates in mice was applied. Sex hormonal levels of testosterone and progesterone were measured using radioimmunoassay while the follicular stimulating hormone and luteinizing hormone were evaluated by direct chemiluminescence. In addition, superoxide dismutase, catalase and glutathione peroxidase were monitored in the hippocampus region using spectrophotometric method. The levels of the hippocampal monoamines, dopamine, noradrenaline and serotonin were analyzed by high performance liquid chromatography while the acetyl choline neurotransmitter was measured by colorimetric method using choline/acetylcholine assay kit. Results: A sharp disruption in the sex hormones levels of testosterone, progesterone, follicular stimulating hormone and luteinizing hormone was demonstrated in the serum of the treated mice. At the same time, a signii cant reduction in the endogenous antioxidant defense enzymes, superoxide dismutase, catalase and glutathione peroxidase was observed in the hippocampus region of the injected mice. Moreover, levels of dopamine, noradrenaline, serotonin and acetyl choline neurotransmitter in the same region were signii cantly af ected as a result of the treatment with Spirulina i ltrate. The gas chromatography-mass spectrometer and liquid chromatography mass spectrometry/mass spectrometry analysis showed the presence of some sterol-like compounds in the cyanobacterial i ltrate. Conclusions: This study demonstrated the capability of Spirulina to release detrimental bioactive metabolites into their surrounding that can disrupt the mammalian endocrine and nervous systems.

  19. Antiviral effect of polysaccharide from Spirulina platensis (PSP) on HSV-2 in vitro

    Institute of Scientific and Technical Information of China (English)

    HONG YU; XIAO ZHU; WEN QING ZHANG; RUI L(U)

    2006-01-01

    To explore the antiviral effect and mechanism of polysaccharide from Spirulina platensis(PSP) on herpes simplex virus type 2 (HSV-2), a standard strain of HSV-2 (333 strain) was used to investigate the antiviral effect of PSP in vitro. PSP in various concentrations was applied to different stages of HSV-2 replication cycle. Finally, the virus infectivity (TCID50), cytopathic effect (CPE),and MTT staining method for viable cells (MTT assay) were used as markers to evaluate the effect of PSP on HSV-2. The quantity of HSV-DNA was detected by real-time fluorescence quantitative PCR(FQ-PCR). The HSV-2 infected Vero cell ultrastructures were observed by transmission electron microscopy (TEM). The results showed that PSP had little cytotoxic effect on Vero cells, it could not directly inactivate HSV-2 infectivity. PSP not only interfered in adsorption of HSV-2 to Vero cells but also inhibited HSV-2 biosynthesis in the cells. FQ-PCR results showed that the inhibitory rate on HSVDNA also increased in a dose-dependent and time-dependent manner. TEM also confirmed that PSP exhibited pronounced inhibitory effect on HSV-2. In conclusion, the antiviral effect of PSP on HSV-2 may be attributed to the inhibition of virus adsorption, virus replication and synthesis in cells.

  20. A method to estimate the biomass of Spirulina platensis cultivated on a solid medium.

    Science.gov (United States)

    Pelizer, Lúcia Helena; Moraes, Iracema de Oliveira

    2014-01-01

    This paper presents a method to estimate the biomass of Spirulina cultivated on solid medium with sugarcane bagasse as a support, in view of the difficulty in determining biomass concentrations in bioprocesses, particularly those conducted in semi-solid or solid media. The genus Spirulina of the family Oscillatoriaceae comprises the group of multicellular filamentous cyanobacteria (blue-green microalgae). Spirulina is used as fish feed in aquaculture, as a food supplement, a source of vitamins, pigments, antioxidants and fatty acids. Therefore, its growth parameters are extremely important in studies of the development and optimization of bioprocesses. For studies of biomass growth, Spirulina platensis was cultured on solid medium using sugarcane bagasse as a support. The biomass thus produced was estimated by determining the protein content of the material grown during the process, based on the ratio of dry weight to protein content obtained in the surface growth experiments. The protein content of the biomass grown in Erlenmeyer flasks on surface medium was examined daily to check the influence of culture time on the protein content of the biomass. The biomass showed an average protein content of 42.2%. This methodology enabled the concentration of biomass adhering to the sugarcane bagasse to be estimated from the indirect measurement of the protein content associated with cell growth.

  1. Antioxidative activity of ethanol extracts from Spirulina platensis and Nostoc linckia measured by various methods

    Directory of Open Access Journals (Sweden)

    Liliana CEPOI

    2009-11-01

    Full Text Available The goal of this work is to determine the level of antioxidative activity of various ethanol extracts from Spirulina platensis and Nostoc linckia biomass, and also to demonstrate the possibility to select suitable methods for evaluation of these characteristics. The methods for determination of antioxidative activity were selected concerning their possible use for complex preparations: phosphomolybdenum method for evaluation of antioxidant capacity (PMRC, radical-scavenging activity by DPPH method (DPPH, antioxidant activity by the ABTS+ radical cation assay (ABTS, Folin-Ciocalteu reducing capacity (FCRC. We showed the presence of antioxidative substances in ethanol extractions from 2 species of cyanobacteria, and possibility to increase their activity varying ethanol concentration. It facilitates the extraction both water- and lipid-soluble components from biomass. Regarding used methods for antioxidative activity determination, we have used only those based on reaction of electrons return (which widely used nowadays in vitro. Obtained in different ways results demonstrate high reduction capacity of the extracts and possibility to select suitable analytical methods for each case.

  2. Aminopyridine modified Spirulina platensis biomass for chromium(VI) adsorption in aqueous solution.

    Science.gov (United States)

    Bayramoglu, Gulay; Akbulut, Aydin; Arica, M Yakup

    Chemical modification of Spirulina platensis biomass was realized by sequential treatment of algal surface with epichlorohydrin and aminopyridine. Adsorptive properties of Cr(VI) ions on native and aminopyridine modified algal biomass were investigated by varying pH, contact time, ionic strength, initial Cr(VI) concentration, and temperature. FTIR and analytical analysis indicated that carboxyl and amino groups were the major functional groups for Cr(VI) ions adsorption. The optimum adsorption was observed at pH 3.0 for native and modified algal biomasses. The adsorption capacity was found to be 79.6 and 158.7 mg g(-1), for native and modified algal biomasses, respectively. For continuous system studies, the experiments were conducted to study the effect of important design parameters such as flow rate and initial concentration of metal ions, and the maximum sorption capacity was observed at a flow rate of 50 mL h(-1), and Cr(VI) ions concentration 200 mg L(-1) with modified biomass. Experimental data fitted a pseudo-second-order equation. The regeneration performance was observed to be 89.6% and 94.3% for native and modified algal biomass, respectively.

  3. Photosynthetic performance of a helical tubular photobioreactor incorporating the cyanobacterium Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshitomo; Hall, D.O. [Univ. of London (United Kingdom); Nouee, J. De La [Univ. Laval, Quebec City, Quebec (Canada). Dept. of Food Science and Technology

    1995-07-20

    The photosynthetic performance of a helical tubular photobioreactor (``Biocoil``), incorporating the filamentous cyanobacterium Spirulina platensis, was investigated. The photobioreactor was constructed in a cylindrical shape with a 0.25-m{sup 2} basal area and a photostage comprising 60 m of transparent PVC tubing of 1.6-cm inner diameter. The inner surface of the cylinder was illuminated with cool white fluorescent lamps; the energy input of photosynthetically active radiation into the photobioreactor was 2,920 kJ per day. An air-lift system incorporating 4% CO{sub 2} was used to circulate the growth medium in the tubing. The maximum productivity achieved in batch culture was 7.18 g dry biomass per day which corresponded to a photosynthetic (PAR) efficiency of 5.45%. The CO{sub 2} was efficiently removed from the gaseous stream; monitoring the CO{sub 2} in the outlet and inlet gas streams showed a 70% removal of CO{sub 2} from the inlet gas over an 8-h period with almost maximum growth rate.

  4. Ultraviolet-B induced damage to photosystem II in intact filaments of Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Kolli, B.K.; Tiwari, S.; Mohanty, P. [Jawaharlal Nehru Univ., New Delhi (India). Schoof of Life Sciences

    1998-05-01

    When Spirulina platensis filaments were exposed to 0.75 mW x m{sup -2} x s{sup -1} of ultraviolet-B radiation (the ultraviolet-B radiation under clear sky condition is {proportional_to}1.0 mW x m{sup -2} x s{sup -1}), an inhibition in photosystem II activity was observed, the inhibition being 90% after 90 min exposure. Upon exposure to ultraviolet-B, the room temperature emission characteristics of Spirulina cells were altered when excited with light primarily absorbed by chlorophyll a or phycobilisomes. When the cells were exposed for 3 h the emission at 685 nm (F{sub 685}), when excited at 440 nm (primarily chlorophyll a absorption), was enhanced compared to 715 nm (F{sub 715}) band of photosystem I suggesting a decrease in energy transfer from photosystem II to photosystem I. Similarly, when the cells were excited at 580 nm (primarily the phycobilisomes), the ratio of emission intensity at 685 nm (F{sub 685}) to that of 655 nm (F{sub 655}) was decreased in the exposed cells. This change in emission characteristics seems to be linked with the uncoupling of the energy transfer from all phycocyanin to chlorophyll a of photosystem II. A small shift in emission peak positions was also indicated when excited either at 440 nm or 580 nm. (orig./AJ)

  5. Continuous cultures of spirulina platensis under photoautotrophic conditions with change in light intensity

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, S. [Osaka Univ., Suita (Japan)532600; Taya, M.; Tone, S. [Kawasaki Heavy Industries Ltd., Kobe (Japan)

    1998-08-01

    In continuous cultures of Spirulina platensis under photoautotrophic conditions, the operation mode to maintain constant cell concentration is examined using culture apparatuses with light path lengths of 0.02 and 0.156 m. The values of dilution rates in the continuous cultures are determined by employing specific growth rates of the cells corresponding to light intensity distribution in liquid medium. When incident light intensity is fixed at 25, 50 or 400 W m{sup minus2}, it is found that the cell concentration in the continuous culture is kept almost constant, and agrees fairly well with the prescribed value of the cell concentration in the range of 0.09 to 2.43 kg m{sup minus3}. It is also demonstrated that the operation mode is valid to obtain stable cell concentrations in the continuous cultures associated with the change in incident light intensity ranging from 25 to 400 W m{sup minus2} during the cultures. 7 refs., 3 figs., 1 tabs.

  6. A method to estimate the biomass of Spirulina platensis cultivated on a solid medium

    Science.gov (United States)

    Pelizer, Lúcia Helena; Moraes, Iracema de Oliveira

    2014-01-01

    This paper presents a method to estimate the biomass of Spirulina cultivated on solid medium with sugarcane bagasse as a support, in view of the difficulty in determining biomass concentrations in bioprocesses, particularly those conducted in semi-solid or solid media. The genus Spirulina of the family Oscillatoriaceae comprises the group of multicellular filamentous cyanobacteria (blue-green microalgae). Spirulina is used as fish feed in aquaculture, as a food supplement, a source of vitamins, pigments, antioxidants and fatty acids. Therefore, its growth parameters are extremely important in studies of the development and optimization of bioprocesses. For studies of biomass growth, Spirulina platensis was cultured on solid medium using sugarcane bagasse as a support. The biomass thus produced was estimated by determining the protein content of the material grown during the process, based on the ratio of dry weight to protein content obtained in the surface growth experiments. The protein content of the biomass grown in Erlenmeyer flasks on surface medium was examined daily to check the influence of culture time on the protein content of the biomass. The biomass showed an average protein content of 42.2%. This methodology enabled the concentration of biomass adhering to the sugarcane bagasse to be estimated from the indirect measurement of the protein content associated with cell growth. PMID:25477928

  7. Modulating Effects of Spirulina platensis against Tilmicosin-Induced Cardiotoxicity in Mice

    Science.gov (United States)

    Ibrahim, Abdelaziz E.; Abdel-Daim, Mohamed Mohamed

    2015-01-01

    Objective Tilmicosin (TIL) is a long-acting macrolide antibiotic used to treat cattle for pathogens that cause bovine respiratory disease. However, overdoses of this medication have been reported to induce cardiac damage. Our experimental objective was to evaluate the protective effects of Spirulina platensis (SP) administration against TIL-induced cardiotoxicity in mice. Materials and Methods Our experimental in vivo animal study used 40 male albino mice that were divided into five groups of eight mice per group. The first group served as a control group and was injected with saline. The second group received SP at dose of 1000 mg/kg body weight for five days. The third group received a single dose of TIL (75 mg/kg, subcutaneously). Groups 4 and 5 were given SP at doses of 500 and 1000 mg/kg body weight for five consecutive days just before administration of TIL at the same dose and regimen used for group 3. Results TIL treated animals showed a significant increase in serum cardiac injury biomarkers as well as cardiac lipid peroxidation, however they had evidence of an inhibition in antioxidant biomarkers. SP normalized elevated serum levels of lactate dehydrogenase (LDH), creatine kinase (CK), and CK-MB. Furthermore, SP reduced TIL-induced lipid peroxidation and oxidative stress in a dose-dependent manner. Conclusion Administration of SP minimized the toxic effects of TIL by its free radicalscavenging and potent antioxidant activity. PMID:25870843

  8. The hypolipidaemic effects of Spirulina (Arthrospira platensis) supplementation in a Cretan population: a prospective study.

    Science.gov (United States)

    Mazokopakis, Elias E; Starakis, Ioannis K; Papadomanolaki, Maria G; Mavroeidi, Niki G; Ganotakis, Emmanuel S

    2014-02-01

    Spirulina (Arthrospira platensis) is a filamentous cyanobacterium used as a food supplement. The objective of the study was to determine the lipid-lowering effects of Spirulina in Cretan Greek dyslipidaemic patients, and to document its effectiveness as a possible alternative treatment for dyslipidaemia. Fifty-two adultCretan outpatients (32 men, 20 women), median age 47 (range, 37-61) years, with recently diagnosed dyslipidaemia, consumed orally 1 g Spirulina (Greek production) per day for 12 weeks. The full lipid profile was measured in fasting blood samples at the beginning and end of the study period. Anthropometric measurements including systolic and diastolic blood pressure, height, weight and body mass index were also recorded. At the end of the 3-month intervention period the mean levels of triglycerides, low density lipoprotein-cholesterol, total cholesterol, non-high density lipoprotein-cholesterol levels, and the ratio of total cholesterol to high-density lipoproteincholesterol were significantly decreased: 16.3% (P Spirulina supplementation at a dose of 1 g daily has powerful hypolipidaemic effects, especially on the triglyceride concentration in dyslipidaemic Cretan outpatients. © 2013 Society of Chemical Industry.

  9. Arsenic-induced genotoxicity in Nile tilapia (Orechromis niloticus); the role of Spirulina platensis extract.

    Science.gov (United States)

    Sayed, Alaa El-Din H; Elbaghdady, Heba Allah M; Zahran, Eman

    2015-12-01

    Arsenic (As) is one of the most relevant environmental global single substance toxicants that have long been regarded as a carcinogenic and genotoxic potential. In this respect, we evaluated the cytogenetic effect of arsenic exposure in Nile tilapia (Oreochromis niloticus), in terms of erythrocyte alteration, apoptosis, and induction of micronuclei. Spirulina platensis (SP) is a filamentous cyanobacterium microalgae with potent dietary phytoantioxidant, anti-inflammatory, and anti-cancerous properties supplementation. The protective role of Spirulina as supplementary feeds was studied in Nile tilapia (O. niloticus) against arsenic-induced cytogenotoxicity. Four groups were assigned as control group (no SP or As), As group (exposed to water-born As in the form of NaAsO2 at 7 ppm), SP1 (SP at 7.5% + As at the same level of exposure), and SP2 (SP at 10% + As at the same level of exposure). As-treated group had a significant increase in all cytogenetic analyses including erythrocyte alteration, apoptosis, and induction of micronuclei after 2 weeks with continuous increase in response after 3 weeks. The combined treatment of Spirulina at two different concentrations of 7.5 and 10% had significantly declined the induction of erythrocyte alteration, apoptosis, and micronuclei formation induced by arsenic intoxication.

  10. Anti-Inflammatory Effects of Spirulina platensis Extract via the Modulation of Histone Deacetylases.

    Science.gov (United States)

    Pham, Tho X; Park, Young-Ki; Lee, Ji-Young

    2016-06-21

    We previously demonstrated that the organic extract of Spirulina platensis (SPE), an edible blue-green alga, possesses potent anti-inflammatory effects. In this study, we investigated if the regulation of histone deacetylases (HDACs) play a role in the anti-inflammatory effect of SPE in macrophages. Treatment of macrophages with SPE rapidly and dose-dependently reduced HDAC2, 3, and 4 proteins which preceded decreases in their mRNA levels. Degradation of HDAC4 protein was attenuated in the presence of inhibitors of calpain proteases, lysosomal acidification, and Ca(2+)/calmodulin-dependent protein kinase II, respectively, but not a proteasome inhibitor. Acetylated histone H3 was increased in SPE-treated macrophages to a similar level as macrophages treated with a pan-HDAC inhibitor, with concomitant inhibition of inflammatory gene expression upon LPS stimulation. Knockdown of HDAC3 increased basal and LPS-induced pro-inflammatory gene expression, while HDAC4 knockdown increased basal expression of interleukin-1β (IL-1β), but attenuated LPS-induced inflammatory gene expression. Chromatin immunoprecipitation showed that SPE decreased p65 binding and H3K9/K14 acetylation at the Il-1β and tumor necrosis factor α (Tnfα) promoters. Our results suggest that SPE increased global histone H3 acetylation by facilitating HDAC protein degradation, but decreases histone H3K9/K14 acetylation and p65 binding at the promoters of Il-1β and Tnfα to exert its anti-inflammatory effect.

  11. Biosorption of copper ions from aqueous solutions by Spirulina platensis biomass

    Directory of Open Access Journals (Sweden)

    Ali A. Al-Homaidan

    2014-01-01

    Full Text Available In this study, the economically important micro-alga (cyanobacterium Spirulina platensis was used as biosorbent for the removal of copper from aqueous solutions. The cyanobacterium was exposed to various concentrations of copper and adsorption of copper by the biomass was evaluated under different conditions that included pH, contact time, temperature, concentration of adsorbate and the concentration of dry biomass. Increased adsorption of copper by the non-living biomass was recorded with gradually increasing pH, and a maximal uptake by the biomass was observed at pH 7. The adsorption of copper was found to increase gradually along with decrease in biomass concentration. Biosorption was found to be at a maximum (90.6%, in a solution containing 100 mg copper/L, at pH 7, with 0.050 g dry biomass and at 37 °C with 90 min of contact time. Analysis of the spectrum obtained with atomic absorption spectrophotometer (AAS, indicated that the adsorbent has a great potential to remove copper from aqueous media contributing to an eco-friendly technology for efficient bioremediation in the natural environment.

  12. Biomass Production and Ester Synthesis by In Situ Transesterification/Esterification Using the Microalga Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Tatiana Rodrigues da Silva Baumgartner

    2013-01-01

    Full Text Available The increasing energy demand and reduction in the availability of nonrenewable energy sources, allied with an increase in public environmental awareness, have stimulated a search for alternative energy sources. The present study was aimed at producing biomass from the microalga Spirulina platensis and at assessing in situ synthesis of alkyl esters via acid transesterification/esterification of biomass to produce biodiesel. Two alcohols (ethanol and methanol and two cosolvents (hexane and chloroform were tested, at different temperatures (30, 45, 60, 75, and 90°C and reaction times (10, 20, 30, 60, and 120 min. The factorial analysis of variance detected an interaction between the factors (: temperature, reaction time, alcohol, and cosolvent. The best yields were obtained with the combination ethanol and chloroform at 60°C, after 30 min of reaction, and with hexane at 45°C, after 10 min of reaction. In situ transesterification/esterification of alga biomass to form esters for biodiesel production adds unconventional dynamics to the use of this feedstock.

  13. Inactive corrinoid-compound significantly decreases in Spirulina platensis grown in a cobalt-deficient medium.

    Science.gov (United States)

    Watanabe, F; Miyamoto, E; Nakano, Y

    2001-11-01

    Spirulina platensis NIES-39 was grown under open culture system in the presence or absence of CoSO(4) (12 microg/L) and/or vitamin B(12) (10 microg/L) to confirm whether CoSO(4) and/or vitamin B(12) stimulate or are essential for growth of the algal cells and for accumulation of vitamin B(12). The addition of CoSO(4) and/or vitamin B(12) could not affect both cell growth and cell yield of the alga. The amount of corrinoid-compound was increased significantly by the addition of CoSO(4) but not by vitamin B(12). A C18 reversed-phase HPLC pattern of the Spirulina corrinoid-compound increased by the addition of CoSO(4) was identical to that of authentic pseudovitamin B(12), which is inactive for human. These results indicate that the algal cells grown in the absence of CoSO(4) are suitable for use of human health foods because the inactive corrinoid-compound can be reduced significantly.

  14. Effects of phosphorus concentration and light intensity on the biomass composition of Arthrospira (Spirulina) platensis.

    Science.gov (United States)

    Markou, Giorgos; Chatzipavlidis, Iordanis; Georgakakis, Dimitris

    2012-08-01

    This paper presents the effects of various phosphorus concentrations (10, 50, 250 and 500 mg l(-1) K(2)HPO(4)) on the biomass production and composition of Arthrospira (Spirulina) platensis in relation to light intensity (24, 42 and 60 μE m(-2) s(-1)). The maximum biomass production was 3,592 ± 392 mg l(-1) and this was observed in 250 mg l(-1) K(2)HPO(4) at 60 μE m(-2) s(-1) light intensity after 32 days of cultivation. A maximum specific growth rate (μ(max)) of 0.55 d(-1) was obtained in 500 mg l(-1) K(2)HPO(4) at 60 μE m(-2) s(-1). The protein, lipid and chlorophyll contents of the biomass varied from 33.59 to 60.57 %, 5.34 to 13.33 % and 0.78 to 2.00 %, respectively. The most significant finding was that phosphorus limitation (10 mg l(-1) K(2)HPO(4)) caused a drastic increase of the carbohydrate content (59.64 %). The effect of phosphorus limitation on the carbohydrate content was independent of the light intensity. The accumulated carbohydrates are proposed to be used as substrate for biofuel generation via one of the appropriate biomass energy conversion technologies. Also, it was observed that phosphorus removal is a function of biomass density, phosphorus concentration and light intensity.

  15. Phycocyanin and phycocyanobilin from Spirulina platensis protect against diabetic nephropathy by inhibiting oxidative stress.

    Science.gov (United States)

    Zheng, Jing; Inoguchi, Toyoshi; Sasaki, Shuji; Maeda, Yasutaka; McCarty, Mark F; Fujii, Masakazu; Ikeda, Noriko; Kobayashi, Kunihisa; Sonoda, Noriyuki; Takayanagi, Ryoichi

    2013-01-15

    We and other investigators have reported that bilirubin and its precursor biliverdin may have beneficial effects on diabetic vascular complications, including nephropathy, via its antioxidant effects. Here, we investigated whether phycocyanin derived from Spirulina platensis, a blue-green algae, and its chromophore phycocyanobilin, which has a chemical structure similar to that of biliverdin, protect against oxidative stress and renal dysfunction in db/db mice, a rodent model for Type 2 diabetes. Oral administration of phycocyanin (300 mg/kg) for 10 wk protected against albuminuria and renal mesangial expansion in db/db mice, and normalized tumor growth factor-β and fibronectin expression. Phycocyanin also normalized urinary and renal oxidative stress markers and the expression of NAD(P)H oxidase components. Similar antioxidant effects were observed following oral administration of phycocyanobilin (15 mg/kg) for 2 wk. Phycocyanobilin, bilirubin, and biliverdin also inhibited NADPH dependent superoxide production in cultured renal mesangial cells. In conclusion, oral administration of phycocyanin and phycocyanobilin may offer a novel and feasible therapeutic approach for preventing diabetic nephropathy.

  16. 螺旋藻的磁处理培养%Cultivation of Spirulina Platensis with a Magnetic Field Treatment

    Institute of Scientific and Technical Information of China (English)

    郭祀远; 李志勇; 李琳; 蔡妙颜; 郑必胜

    2002-01-01

    The enhancement of cultivation of Spirulina platensis with a magnetic field treatment technology was investigated. It was found that the cultivation of Spirulina platensis could be obviously promoted by a suitable magnetic field treatment. When microalgae Spirulina platensis were cultured under an extraneous magnetic field with intensity of 200~320 kA/m, the maximum dry weight of cells was 2.76 g/L on the sixth growth day, which was 46.8% more than the control. Meanwhile the specific growth rate increased from 0.4 to 0.6 d-1, and the cultural period could be cut down for 2~3 d. At the same time, the content of proteins in Spirulina platensis increased by 5.2 mg/g, the total amino acids (except tryptophan) in Spirulina platensis increased by 0.71 mg/g, where essential amino acids increased by 3.15 mg/g. In addition, the contents of trace elements such as Sr, Ni, Cu, Mn and Zn also increased sharply, e.g., Sr and Ni were 22.3 and 5.1 times more than the controls respectively. Finally, the paper presents a brief discussion on the stimulation of magnetic field treatment of the culture of Spirulina platensis and points out that it is relative to the promotion of photosynthesis and the enhancement of nutritional assimilation.%就磁场处理技术对螺旋藻培养过程的强化进行了研究,发现螺旋藻的培养能明显地被适当的磁场处理所刺激.在强度为200~320 kA/m的外加磁场作用下培养至第6天,螺旋藻最大细胞干重达2.76 g/L, 比同等条件下的空白对照试样多46.8 %;其比生长率由0.4 d-1增至0.6 d-1,培养周期可缩短2~3 d.同时,螺旋藻中蛋白质的含量增加了5.2 mg/g;氨基酸总含量(除色氨酸外)增加了0.71 mg/g,其中必需氨基酸增加了 3.15 mg/g.此外,微量元素 Sr、Ni、Cu、Mn和Zn等均有显著增加,其中Sr和Ni分别增加了22.3和5.1倍.文中最后讨论了磁场处理对螺旋藻培养的强化机制,指出这种刺激作用与磁场处理加速了螺旋藻的光合

  17. Tuning giant anomalous Hall resistance ratio in perpendicular Hall balance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. Y.; Yang, G. [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, S. G., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, J. L. [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Wang, R. M. [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Amsellem, E.; Kohn, A. [Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Yu, G. H., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-04-13

    Anomalous Hall effect at room temperature in perpendicular Hall balance with a core structure of [Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4} has been tuned by functional CoO layers, where [Pt/Co]{sub 4} multilayers exhibit perpendicular magnetic anisotropy. A giant Hall resistance ratio up to 69 900% and saturation Hall resistance (R{sub S}{sup P}) up to 2590 mΩ were obtained in CoO/[Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4}/CoO system, which is 302% and 146% larger than that in the structure without CoO layers, respectively. Transmission electron microscopy shows highly textured [Co/Pt]{sub 4} multilayers and oxide layers with local epitaxial relations, indicating that the crystallographic structure has significant influence on spin dependent transport properties.

  18. Variable variance Preisach model for multilayers with perpendicular magnetic anisotropy

    Science.gov (United States)

    Franco, A. F.; Gonzalez-Fuentes, C.; Morales, R.; Ross, C. A.; Dumas, R.; Åkerman, J.; Garcia, C.

    2016-08-01

    We present a variable variance Preisach model that fully accounts for the different magnetization processes of a multilayer structure with perpendicular magnetic anisotropy by adjusting the evolution of the interaction variance as the magnetization changes. We successfully compare in a quantitative manner the results obtained with this model to experimental hysteresis loops of several [CoFeB/Pd ] n multilayers. The effect of the number of repetitions and the thicknesses of the CoFeB and Pd layers on the magnetization reversal of the multilayer structure is studied, and it is found that many of the observed phenomena can be attributed to an increase of the magnetostatic interactions and subsequent decrease of the size of the magnetic domains. Increasing the CoFeB thickness leads to the disappearance of the perpendicular anisotropy, and such a minimum thickness of the Pd layer is necessary to achieve an out-of-plane magnetization.

  19. Influence of pH, temperature, and urea molar flowrate on Arthrospira platensis fed-batch cultivation: a kinetic and thermodynamic approach.

    Science.gov (United States)

    Sánchez-Luna, Luis Dante; Bezerra, Raquel Pedrosa; Matsudo, Marcelo Chuei; Sato, Sunao; Converti, Attilio; de Carvalho, João Carlos Monteiro

    2007-03-01

    Arthrospira platensis was cultivated photoautotrophically at 6.0 klux light intensity in 5.0-L open tanks, using a mineral medium containing urea as nitrogen source. Fed-batch experiments were performed at constant flowrate. A central composite factorial design combined to response surface methodology (RSM) was utilized to determine the relationship between the selected response variables (cell concentration after 10 days, X(m), cell productivity, P(X), and nitrogen-to-cell conversion factor, Y(X/N)) and codified values of the independent variables (pH, temperature, T, and urea flowrate, K). By applying the quadratic regression analysis, the equations describing the behaviors of these responses as simultaneous functions of the selected independent variables were determined, and the conditions for X(m) and P(X) optimization were estimated (pH 9.5, T = 29 degrees C, and K = 0.551 mM/day). The experimental data obtained under these conditions (X(m) = 749 mg/L; P(X) = 69.9 mg/L.day) were very close to the estimated ones (X(m) = 721 mg/L; P(X) = 67.1 mg/L.day). Additional cultivations were carried out under the above best conditions of pH control and urea flowrate at variable temperature. Consistently with the results of RSM, the best growth temperature was 29 degrees C. The maximum specific growth rates at different temperatures were used to estimate the thermodynamic parameters of growth (DeltaH* = 59.3 kJ/mol; DeltaS* = -0.147 kJ/mol.K; DeltaG* = 103 kJ/mol) and its thermal inactivation (DeltaH(D) (o) = 72.0 kJ/mol; DeltaS(D) (o) = 0.144 kJ/mol.K; DeltaG(D) (o) = 29.1 kJ/mol).

  20. Effect of Supercritical Carbon Dioxide Extraction Parameters on the Biological Activities and Metabolites Present in Extracts from Arthrospira platensis

    Science.gov (United States)

    Esquivel-Hernández, Diego A.; Rodríguez-Rodríguez, José; Cuéllar-Bermúdez, Sara P.; García-Pérez, J. Saúl; Mancera-Andrade, Elena I.; Núñez-Echevarría, Jade E.; Ontiveros-Valencia, Aura; Rostro-Alanis, Magdalena; García-García, Rebeca M.; Torres, J. Antonio; Chen, Wei Ning; Parra-Saldívar, Roberto

    2017-01-01

    Arthrospira platensis was used to obtain functional extracts through supercritical carbon dioxide extraction (SFE-CO2). Pressure (P), temperature (T), co-solvent (CX), static extraction (SX), dispersant (Di) and dynamic extraction (DX) were evaluated as process parameters through a Plackett–Burman design. The maximum extract yield obtained was 7.48 ± 0.15% w/w. The maximum contents of bioactive metabolites in extracts were 0.69 ± 0.09 µg/g of riboflavin, 5.49 ± 0.10 µg/g of α-tocopherol, 524.46 ± 0.10 µg/g of β-carotene, 1.44 ± 0.10 µg/g of lutein and 32.11 ± 0.12 mg/g of fatty acids with 39.38% of palmitic acid, 20.63% of linoleic acid and 30.27% of γ-linolenic acid. A. platensis extracts had an antioxidant activity of 76.47 ± 0.71 µg GAE/g by Folin–Ciocalteu assay, 0.52 ± 0.02, 0.40 ± 0.01 and 1.47 ± 0.02 µmol TE/g by DPPH, FRAP and TEAC assays, respectively. These extracts showed antimicrobial activity against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Overall, co-solvent was the most significant factor for all measured effects (p < 0.05). Arthrospira platensis represents a sustainable source of bioactive compounds through SFE using the following extraction parameters P: 450 bar, CX: 11 g/min, SX: 15 min, DX: 25 min, T: 60 °C and Di: 35 g. PMID:28604646

  1. Bioaccumulation of Pb2+ and Its Effects on Growth, Morphology and Pigment Contents of Spirulina (Arthrospira)platensis

    Institute of Scientific and Technical Information of China (English)

    K. K. I. U. Arunakumara; ZHANG Xuecheng; SONG Xiaojin

    2008-01-01

    A laboratory experiment was conducted to assess the bioaccumulation of Pb2+ and its effects on growth,morphology andpigment contents of Spirulina (Arthrospira) platensis.The specimen cultured in Zarrouk liquid medium was treated with variousinitial metal concentrations (0,5,10,30,50 and 100 μgmL-1).The growth of S.platensis was adversely affected by Pb2+ at high con-centrations (30,50 and 100 μg mL-1).However,at low concentrations (5 μg mL-1),Pb2+ could stimulate its growth slightly.The pig-ment contents (chlorophyll α and β carotene) were decreased in a dose-dependent manner.The highest reductions (67% and 53%respectively in chlorophyll α and β carotene) were observed in 100 μg mL-1 treatment group.The LC50 (96 h) of Pb2+ was measured as75.34μg mL-1.Apart from a few cases of filament breakages at elevated concentrations (50 and 100μg mL-1),morphological abnor-malities are not specific.Metal bioaccumulation increased with Pb2+ concentrations,but decreased with exposure time.The maxi-mum accumulated amount was 188 mgg-1 dry weight.The bioconcentration factor (BCF) reached to a peak at day 2,followed by agradual reduction for all the exposure concentrations.S.platensis is able to tolerate considerably high Pb2+ concentrations.Conse-quently it can be used as a potential species to remove heavy metal from contaminated waters.

  2. Bioaccumulation of Pb2+ and its effects on growth, morphology and pigment contents of Spirulina ( Arthrospira) platensis

    Science.gov (United States)

    Arunakumara, K. K. I. U.; Zhang, Xuecheng; Song, Xiaojin

    2008-11-01

    A laboratory experiment was conducted to assess the bioaccumulation of Pb2+ and its effects on growth, morphology and pigment contents of Spirulina (Arthrospira) platensis. The specimen cultured in Zarrouk liquid medium was treated with various initial metal concentrations (0, 5, 10, 30, 50 and 100 μg mL-1). The growth of S. platensis was adversely affected by Pb2+ at high concentrations (30, 50 and 100 μg mL-1). However, at low concentrations (5 μg mL-1), Pb2+ could stimulate its growth slightly. The pigment contents (chlorophyll α and β carotene) were decreased in a dose-dependent manner. The highest reductions (67% and 53% respectively in chlorophyll α and β carotene) were observed in 100 μg mL-1 treatment group. The LC50 (96 h) of Pb2+ was measured as 75.34 μg mL-1. Apart from a few cases of filament breakages at elevated concentrations (50 and 100 μg mL-1), morphological abnormalities are not specific. Metal bioaccumulation increased with Pb2+ concentrations, but decreased with exposure time. The maximum accumulated amount was 188 mg g-1 dry weight. The bioconcentration factor (BCF) reached to a peak at day 2, followed by a gradual reduction for all the exposure concentrations. S. platensis is able to tolerate considerably high Pb2+ concentrations. Consequently it can be used as a potential species to remove heavy metal from contaminated waters.

  3. Selenium-induced Changes in Activities of Antioxidant Enzymes and Content of Photosynthetic Pigments in Spirulina platensis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Spirulina platensis exposed to various selenium (Se) concentrations (0,10,20, 40, 80, 150, 175, 200, 250 mglL) accumulated high amounts of Se in a dose- and time-dependent manner. Under low Se concentrations (≤150 mg/L), Se induced increases in biomass concentration, content of photosynthetic pigments, and activities of glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT) and Gua-dep peroxidases (POD), which indicates that antioxidant enzymes play an important role in protecting cells from Se stress. Higher Se concentrations (≥ 175 mg/L) led to higher Se accumulation and increases in activities of GPX, SOD, CAT and POD, but also induced lipid peroxidation (LPO) coupled with potassium leakage and decreases in biomass concentration and contents of photosynthetic pigment. The results indicate that increases in activities of the antioxidant enzymes were not sufficient to protect cell membranes against Se stress. Time-dependent variations in the activities of antioxidant enzymes, contents of chlorophyll a and carotenoid and the LPO level were also investigated under representative Se concentrations of 40 and 200 mg/L. Opposite variation trends between SOD-CAT activities, and GPX-POD-APX activities were observed during the growth cycles. The results showed that the prevention of damage to cell membranes of S. platensis cells could be achieved by cooperative effects of SOD-CAT and GPX-POD-APX enzymes. This study concludes that S. platensis possessed tolerance to Se and could protect itself from phytotoxicity induced by Se by altering various metabolic processes.

  4. Effect of Supercritical Carbon Dioxide Extraction Parameters on the Biological Activities and Metabolites Present in Extracts from Arthrospira platensis

    Directory of Open Access Journals (Sweden)

    Diego A. Esquivel-Hernández

    2017-06-01

    Full Text Available Arthrospira platensis was used to obtain functional extracts through supercritical carbon dioxide extraction (SFE-CO2. Pressure (P, temperature (T, co-solvent (CX, static extraction (SX, dispersant (Di and dynamic extraction (DX were evaluated as process parameters through a Plackett–Burman design. The maximum extract yield obtained was 7.48 ± 0.15% w/w. The maximum contents of bioactive metabolites in extracts were 0.69 ± 0.09 µg/g of riboflavin, 5.49 ± 0.10 µg/g of α-tocopherol, 524.46 ± 0.10 µg/g of β-carotene, 1.44 ± 0.10 µg/g of lutein and 32.11 ± 0.12 mg/g of fatty acids with 39.38% of palmitic acid, 20.63% of linoleic acid and 30.27% of γ-linolenic acid. A. platensis extracts had an antioxidant activity of 76.47 ± 0.71 µg GAE/g by Folin–Ciocalteu assay, 0.52 ± 0.02, 0.40 ± 0.01 and 1.47 ± 0.02 µmol TE/g by DPPH, FRAP and TEAC assays, respectively. These extracts showed antimicrobial activity against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Overall, co-solvent was the most significant factor for all measured effects (p < 0.05. Arthrospira platensis represents a sustainable source of bioactive compounds through SFE using the following extraction parameters P: 450 bar, CX: 11 g/min, SX: 15 min, DX: 25 min, T: 60 °C and Di: 35 g.

  5. Optimised extraction of β-carotene from Spirulina platensis and hypoglycaemic effect in streptozotocin-induced diabetic mice.

    Science.gov (United States)

    Ma, Qiu-Yue; Fang, Ming; Zheng, Jia-Hui; Ren, Di-Feng; Lu, Jun

    2016-03-30

    Spirulina platensis is rich in β-carotene, which possesses many important biological activities. This study investigated the ultrasound-assisted extraction and purification of β-carotene from Spirulina platensis by using response surface methodology (RSM), determined its antioxidant capacity in vitro and explored its hypoglycaemic effect in diabetic mice. The raw β-carotene extract with a concentration of 1942.14 ± 10.03 µg mL(-1) was obtained at the optimised condition by RSM (0.40 of the solid-liquid ratio, 51% of the extraction power, and 17 min of the extraction time), and the purity of evaporated β-carotene extract reached 816.32 ± 10.57 mg g(-1) after purified by a NKA-9 resin with a sampling and elution rate of 1 mL min(-1) . The β-carotene extract scavenged 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radicals with the highest ratios of 44 ± 0.26% and 35 ± 0.45% respectively, and exhibited strong inhibiting capacity on anti-lipid peroxidation. The blood glucose level of streptozotocin-induced diabetic mice was significantly reduced from 15.81 ± 1.71 mmol L(-1) to 8.10 ± 0.88 mmol L(-1) after 10 d administration of the β-carotene extract [100 mg kg(-1) body weight (BW)], and the increased food and water intakes in the diabetic mice were also significantly relieved after β-carotene treatment. Our results suggested that extraction of β-carotene from Spirulina platensis had potential prospects in scaled-up industrialisation and healthcare applications. © 2015 Society of Chemical Industry.

  6. Harmonic measures of slit sides perpendicular to the domain boundary

    CERN Document Server

    Prokhorov, Dmitri

    2012-01-01

    The article is devoted to the geometry of solutions to the chordal Loewner equation which is based on comparison of singular solutions and harmonic measures for the sides of a slit in domains generated by a driving term. It is proved that harmonic measures of two sides of a slit in the upper half-plane which is perpendicular to the real axis are asymptotically equal to each other.

  7. Artificially engineered Heusler ferrimagnetic superlattice exhibiting perpendicular magnetic anisotropy

    OpenAIRE

    Ma, Q.L.; X. M. Zhang; Miyazaki, T.; Mizukami, S.

    2015-01-01

    To extend density limits in magnetic recording industry, two separate strategies were developed to build the storage bit in last decade, introduction of perpendicular magnetic anisotropy (PMA) and adoption of ferrimagnetism/antiferromagnetism. Meanwhile, these properties significantly improve device performance, such as reducing spin-transfer torque energy consumption and decreasing signal-amplitude-loss. However, materials combining PMA and antiferromagnetism rather than transition-metal/rar...

  8. Perpendicular magnetic anisotropy of CoSiB/Pt multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. S.; Yim, H. I. [Sookmyung Women' s University, Seoul (Korea, Republic of); Hwang, J. Y.; Lee, S. B. [Hanyang University, Seoul (Korea, Republic of); Kim, T. W. [Sejong University, Seoul (Korea, Republic of)

    2010-12-15

    We have investigated the perpendicular magnetic anisotropy of [CoSiB t{sub CoSiB}/Pt t{sub Pt}]{sub n} multilayers as a function of the CoSiB and the Pt thicknesses and the number of repetition of the CoSiB/Pt bilayers. The coercivity (H{sub c}) and the saturation magnetization (M{sub s}) of the amorphous ferromagnetic material Co{sub 75}Si{sub 15}B{sub 10} were taken to be 1.6 Oe and 407 emu/cm{sup 3}, respectively. The H{sub c} in [CoSiB t{sub CoSiB}/Pt 14 A]{sub 5} multilayers increases with increasing t{sub CoSiB} to reach a maximum at t{sub CoSiB} = 3 A and then decreases for t{sub CoSiB} > 3 A. The highest H{sub c} of 224 Oe and the highest perpendicular magnetic anisotropy K{sub u} of 2 x 10{sup 6} erg/cm{sup 3} were obtained in the [CoSiB 3 A/Pt 14 A]{sub 5} multilayer. Additional Pt layers do not contribute to the perpendicular magnetic anisotropy. The single-domain structure evolves into a striped multidomain structure as the bilayer repetition number n increases above 6.

  9. Hallazgo de Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae) en el estado brasileño de "Rio Grande do Sul"

    OpenAIRE

    Salvatella,Roberto; Basmadjián,Yester; Rosa,Raquel; Martínez, María; Mendaro,Gabriela; Civila,Eduardo

    1991-01-01

    Triatoma platensis Neiva 1913 (Hemiptera, Triatominae), especie ornitófila, con área de dispersión conocida en Argentina, Bolivia, Paraguay y Uruguay es notificada en un primer registro para Brasil. Hallada en el municipio de Uruguaiana (Río Grande do Sul) en nidos de Anumbius annumbi (Vieillot, 1817) (Passeriformes, Furnariidae) donde cohabitaba con cricétidos de la especie Orizomys flavescens. Ningún ejemplar de los siete colectados se presentó infectado por Trypanosoma cruzi.

  10. Investigation of the Structure and Element Composition of C-Phycocyanin Extracted from the Microalgae Spirulina platensis

    CERN Document Server

    Mosulishvili, L M; Kirkesali, E I; Khizanishvili, A I; Frontasyeva, M V; Pavlov, S S; Gundorina, S F

    2002-01-01

    The structure and element composition of C-phycocyanin (C-PC) extracted from the blue-green alga Spirulina platensis were studied. The behavior of structural subunits forming phycobilisomes in the purification process was studied by capillary electrophoresis. Their proportion in high-purity C-PC was determined. The element composition of C-PC of different purity was studied by means of epithermal neutron activation analysis, and metals which may form macromolecular complexes with C-PC were determined (Zn, Cr, Ni, Co, As, Sr, Mo, Ag, Hg). It was shown that contents of toxic metals did not exceed accepted permissible levels for the human organism.

  11. Application of Epithermal Neutron Activation Analysis to Investigate Accumulation and Adsorption of Mercury by Spirulina platensis Biomass

    CERN Document Server

    Mosulishvili, L M; Khizanishvili, A I; Frontasyeva, M V; Kirkesali, E I; Aksenova, N G

    2004-01-01

    Epithermal neutron activation analysis was used to study interaction of blue-green alga Spirulina platensis with toxic metal mercury. Various concentrations of Hg(II) were added to cell cultures in a nutrient medium. The dynamics of accumulation of Hg was investigated over several days in relation to Spirulina biomass growth. The process of Hg adsorption by Spirulina biomass was studied in short-time experiments. The isotherm of adsorption was carried out in Freindlich coordinates. Natural Spirulina biomass has potential to be used in the remediation of sewage waters at Hg concentrations \\sim 100 {\\mu}g/l.

  12. Cultivation of Arthrospira (spirulina) platensis in desalinator wastewater and salinated synthetic medium: protein content and amino-acid profile

    OpenAIRE

    2008-01-01

    Arthrospira (Spirulina) platensis was cultivated in laboratory under controlled conditions (30ºC, photoperiod of 12 hours light/dark provided by fluorescent lamps at a light intensity of 140 µmol photons.m-2.s-1 and constant bubbling air) in three different culture media: (1) Paoletti medium (control), (2) Paoletti supplemented with 1 g.L-1 NaCl (salinated water) and (3) Paoletti medium prepared with desalinator wastewater. The effects of these treatments on growth, protein content and amino ...

  13. Temperature Influences on the Expression of GFP Promoted by the Upstream Sequence of cpcB from Arthrospira platensis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to investigate the regulation mechanism of the phycocyanin gene, a series of functional analyses of the upstream sequence of cpcB gene from Arthrospira platensis were conducted in E. coli with green fluorescent protein encoding gene (gfp) as the reporter. Results showed that the gfp gene could express at a high level under the promotion of the upstream sequence, suggesting the existence of some strong promoter elements in it. The expression of GFP was influenced by temperature. Higher temperature led to higher expression level. The bioinformatics analyses followed by mutation analyses on the secondary structure of translation initiation region (TIR) revealed that RNA thermosensor might account for the temperature regulation.

  14. Temperature influences on the expression of GFP promoted by the upstream sequence of cpcB from Arthrospira platensis

    Science.gov (United States)

    Lu, Yongzhong; Zhang, Xuecheng

    2007-07-01

    In order to investigate the regulation mechanism of the phycocyanin gene, a series of functional analyses of the upstream sequence of cpcB gene from Arthrospira platensis were conducted in E. coli with green fluorescent protein encoding gene (gfp) as the reporter. Results showed that the gfp gene could express at a high level under the promotion of the upstream sequence, suggesting the existence of some strong promoter elements in it. The expression of GFP was influenced by temperature. Higher temperature led to higher expression level. The bioinformatics analyses followed by mutation analyses on the secondary structure of translation initiation region (TIR) revealed that RNA thermosensor might account for the temperature regulation.

  15. Fluorescence Quenching Property of C-Phycocyanin from Spirulina platensis and its Binding Efficacy with Viable Cell Components.

    Science.gov (United States)

    Paswan, Meenakshi B; Chudasama, Meghna M; Mitra, Madhusree; Bhayani, Khushbu; George, Basil; Chatterjee, Shruti; Mishra, Sandhya

    2016-03-01

    Phycocyanin is a natural brilliant blue colored, fluorescent protein, which is commonly present in cyanobacteria. In this study, C-phycocyanin was extracted and purified from Spirulina platensis, which are multicellular and filamentous cyanobacteria of greater importance because of its various biological and pharmacological potential. It was analyzed for its binding affinity towards blood cells, algal cells, genomic DNA of microalgae, and bacteria at different temperature and incubation time. It showed good binding affinity with these components even at low concentration of 2.5 μM. The purpose of this study was to evaluate the applicability of C-phycocyanin as a green fluorescent dye substituting carcinogenic chemical dyes.

  16. Cultivo de Arthrospira platensis (Spirulina en fotobiorreactor tubular doblemente curvado a condiciones ambientales en el sur del Perú

    Directory of Open Access Journals (Sweden)

    Ronald Eleazar Huarachi Olivera

    2015-05-01

    Full Text Available Título en ingles: Cultivation of Arthrospira platensis (Spirulina in curved doubly tubular photobioreactor to environmental conditions in the South of the PeruTítulo corto: Cultivo de Arthrospira platensis (Spirulina en fotobiorreactorResumen: El presente trabajo investigó el cultivo de la microalga Arthrospira platensis (Spirulina en valores de productividad cultivado en fotobiorreactor tubular doblemente curvado a condiciones ambientales con el fin de aprovechar la alta radiación solar de la región Arequipa en el sur de Perú (16°24´50´´ LS; 71°32´02´´ LO; 2344 msnm. El fotobiorreactor fue construido con un tubo transparente de policloruro de vinilo  (PVC. La productividad del cultivo fue de 13.9 g/m2 en 14 días ó 1 g/m2/día y una concentración de clorofila - “a” de 0.00785 mg/L con una máxima radiación de 1179 W/m2, y una iluminación de 121500 lux, convirtiendo sus filamentos helicoidales a morfologías anormales, tales como formas irregulares curvas e incluso lineales con fragmentaciones, demostrando que el cultivo se vio afectado por la alta radiación y las variaciones de  temperaturas de Arequipa.Palabras clave: cultivo, fotobiorreactor, productividad, sur de Perú, Spirulina.Abstract: The present work investigated the cultivation of microalgae Arthrospira platensis (Spirulina in productivity values cultivated in doubly curved tubular photobioreactor to environmental conditions in order to take advantage of the high solar radiation of the Arequipa region in southern Peru (16°24´50´´ LS; 71°32´02´´LW; 2344 msnm.. The photobioreactor was built with a transparent tube of polyvinyl chloride (PVC. The productivity of the crop was 13.9 g/m2 in 14 days or 1 g/m2/day and a concentration of chlorophyll - "a" 0.00785 mg/L with a maximum radiation of 1179 W/m2, and a 121500 lux illumination, making its helical filaments abnormal morphologies, such as curves and linear even irregular shapes with fragmentation

  17. Diseño conceptual de un proceso de cultivo y obtención de Cyanobacteria Arthrospira Platensis

    OpenAIRE

    Torres Urango, Bernardo David; Correa Trujillo, Daniel

    2008-01-01

    Se evaluó el crecimiento del alga Spirulina Platensis en la ciudad de Medellín a presión y temperatura promedio de 0.84 atm y 24°C respectivamente, en tres medios de cultivo: Medio Zarrouk, Medio Utex y Medio Urea (experimental). Las pruebas fueron realizadas a escala de laboratorio en tanques de 2 l, con aireación constante, la agitación fue proporcionada por la aireación, rango de pH entre 9-11; se realizaron mediciones diarias para controlar la variable de crecimiento mediante el cálculo d...

  18. Removal of Nitrate and Phosphate from Municipal Wastewater Sludge by Chlorella vulgaris, Spirulina platensis and Scenedesmus quadricauda

    Directory of Open Access Journals (Sweden)

    Jalal K.C.A

    2011-12-01

    Full Text Available Nitrate and phosphorus in wastewater contribute to health and environmental threats as they are linked to illnesses as well as ecosystem disruption via algal blooms in contaminated water bodies. Based on above perspectives a comparative study was conducted on three local freshwater microalgae:Chlorella vulgaris, Spirulina platensis and Scenedesmus quadricauda to evaluate their effects on nitrate and phosphorus removal from municipal wastewater sludge (MWS. Algae performance in removing nitrate and phosphorus was evaluated by measuring nitrate and phosphorus content of MWS incubated with the strains for 7 days. Instantaneous readings were taken every 48 hours to determine periodic levels of the nutrients phosphate and nitrate. BOD5 was also evaluated to identify the strain with the most robust growth that would demand for oxygen the most in the dark. Spirulina platensis was shown as the most efficient microalgae to reduce nitrate in MWS and the best-growing among the three strains, while Chlorella vulgaris removed phosphorus the most effectively. Thus Spirulina and Chlorella could be potential candidates by showing their intrinsic merit for the reduction of phosphate and nitrate in wastewater treatment.ABSTRAK: Nitrat dan fosforus dalam air sisa menggugat kesihatan dan mengancam alam sekitar memandangkan ia berkait dengan penyakit-penyakit serta gangguan terhadap ekosistem melalui pembiakan alga dalam air yang tercemar. Berdasarkan perspektif di atas, satu kajian perbandingan telah dijalankan terhadap tiga mikro alga air tawar tempatan : Chlorella vulgaris, Spirulina platensis dan Scenedesmus quadricauda untuk dinilai kesannya terhadap penyingkiran nitrat dan fosforus dari enap cemar air sisa bandaran (municipal wastewater sludge (MWS. Kebolehan alga dalam penyingkiran nitrat dan fosforus dikaji dengan menyukat kandungan nitrat dan fosforus dalam MWS yang dieramkan dengan strain ini selama 7 hari. Bacaan serta-merta diambil setiap 48 jam untuk

  19. Influence of the Systemic Application of Blue–Green Spirulina platensis Algae on the Cutaneous Carotenoids and Elastic Fibers in Vivo

    Directory of Open Access Journals (Sweden)

    Maxim E. Darvin

    2015-09-01

    Full Text Available The objective of the study was to investigate the influence of a food supplement rich in antioxidants on the antioxidant status of the skin. For this reason, the blue-green algae Spirulina platensis powder was used for oral application during eight weeks. The effect of oral application of the antioxidant-containing Spirulina platensis on characteristic skin aging parameters, e.g., concentration of cutaneous carotenoids and the collagen/elastin index (SAAID, was investigated in vivo. A significant average increase from 2.67 ± 0.86 arb. units to 3.25 ± 0.93 arb. units (p < 0.001 in the cutaneous carotenoid concentration was detected subsequent to oral application of the carotenoid-containing Spirulina platensis powder, showing a significant improvement of the antioxidant status of the skin. A slight but not significant increase (p = 0.33 in the dermal SAAID mean values was measured from −0.54 ± 0.11 to −0.51 ± 0.11 subsequent to oral intake of Spirulina platensis powder.

  20. Application of Spirulina platensis for prevention of white spot syndrome virus in post larvae and juvenile black tiger shrimp (Penaeus monodon

    Directory of Open Access Journals (Sweden)

    Hemtanon, P.

    2005-02-01

    Full Text Available In this study, the extract of Spirulina platensis were examined in vitro to inhibit white spot syndrome virus (WSSV and application of dry S. platensis in diet for prevention of white spot syndrome (WSS in post larvae and juvenile black tiger shrimp (Penaeus monodon. The results showed that the lowest concentration of the extract for inhibiting WSSV was 0.01 mg/ml, while the optimum concentration was found to be 0.1 mg/ ml in which the mortality rate of the shrimp was 4 percents and infection was not detected from survivalshrimp by the immunohistochemistry method.Furthermore, The results showed that the survival rate of the post larvae fed on steamed egg containing dry S. platensis 5 g/kg of diet was higher than that of the control (p<0.05 when challenged with WSSV and no WSSV infected shrimp examine by polymerase chain reaction (PCR assay. In the case of juvenile shrimp, the survival rate of shrimp fed pellets containing dry S. platensis 10 g/kg of diet was higher than that of the control group (p<0.05 after challenging with WSSV. Moreover percent of WSSV infection in the survival shrimp using the immunohistochemistry method was lower than that of the control group.

  1. Enhancement of human adaptive immune responses by administration of a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis

    DEFF Research Database (Denmark)

    Pedersen, Morten Løbner; Walsted, Anette; Larsen, Rune

    2008-01-01

    The effect of consumption of Immulina, a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis, on adaptive immune responses was investigated by evaluation of changes in leukocyte responsiveness to two foreign recall antigens, Candida albicans (CA) and tetanus...

  2. Protective effects of a polysaccharide from Spirulina platensis on dopaminergic neurons in an MPTP-induced Parkinson's disease model in C57BL/6J mice

    Science.gov (United States)

    Zhang, Fang; Lu, Jian; Zhang, Ji-guo; Xie, Jun-xia

    2015-01-01

    The present study aimed to determine whether a polysaccharide obtained from Spirulina platensis shows protective effects on dopaminergic neurons. A Parkinson's disease model was established through the intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in C57BL/6J mice. Prior to the MPTP injection, some mice were pretreated with intraperitoneal injections of a polysaccharide derived from Spirulina platensis once daily for 10 days. The results showed that the immunoreactive staining and mRNA expression of the dopamine transporter and tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis, in the substantia nigra, were significantly increased in mice pretreated with 800 mg/kg of the polysaccharide compared with those in MPTP-treated mice. The activities of superoxide dismutase and glutathione peroxidase in the serum and midbrain were also increased significantly in mice injected with MPTP after pretreatment with the polysaccharide from Spirulina platensis. By contrast, the activity of monoamine oxidase B in serum and midbrain maintained unchanged. These experimental findings indicate that the polysaccharide obtained from Spirulina platensis plays a protective role against the MPTP-induced loss of dopaminergic neurons in C57BL/6J mice, and that the antioxidative properties of this polysaccharide likely underlie its neuroprotective effect. PMID:25883632

  3. Protective effects of a polysaccharide from Spirulina platensis on dopaminergic neurons in an MPTP-induced Parkinson′s disease model in C57BL/6J mice

    Directory of Open Access Journals (Sweden)

    Fang Zhang

    2015-01-01

    Full Text Available The present study aimed to determine whether a polysaccharide obtained from Spirulina platensis shows protective effects on dopaminergic neurons. A Parkinson′s disease model was established through the intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP in C57BL/6J mice. Prior to the MPTP injection, some mice were pretreated with intraperitoneal injections of a polysaccharide derived from Spirulina platensis once daily for 10 days. The results showed that the immunoreactive staining and mRNA expression of the dopamine transporter and tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis, in the substantia nigra, were significantly increased in mice pretreated with 800 mg/kg of the polysaccharide compared with those in MPTP-treated mice. The activities of superoxide dismutase and glutathione peroxidase in the serum and midbrain were also increased significantly in mice injected with MPTP after pretreatment with the polysaccharide from Spirulina platensis. By contrast, the activity of monoamine oxidase B in serum and midbrain maintained unchanged. These experimental findings indicate that the polysaccharide obtained from Spirulina platensis plays a protective role against the MPTP-induced loss of dopaminergic neurons in C57BL/6J mice, and that the antioxidative properties of this polysaccharide likely underlie its neuroprotective effect.

  4. Effect of 2,4-dichlorophenoxyacetic acid on growth, protein and chlorophyll-a content of Chlorella vulgaris and Spirulina platensis cells.

    Science.gov (United States)

    Saygideger, Saadet Demirors; Okkay, Ozlem

    2008-03-01

    In this study, effect of different 2,4 -dichlorophenoxyacetic acid (2,4-D) concentrations (0.0, 9.10(-5), 9.10(-4), 9.10(-3) and 9.10(-2) mM) on growth rate, content of protein and chlorophyll-a in Chlorella vulgaris and Spirulina platensis cells was investigated. The most stimulatory effect on growth rate, protein and pigment ratio of C. vulgaris and S. platensis was observed at 9.10(-4) mM concentrations of 2,4-D. The results show that low concentrations of 2,4-D have hormonal effect due to being a synthetic auxin. Cell number protein and pigment rates were inhibited at 9.10(-2) mM concentration in C. vulgaris. Such parameters were inhibited in S. platensis, both at 9.10(-3) and 9.10(-2) mM 2,4-D concentrations. This is due to herbicidal effect of high concentrations of 2,4-D. S. platensis was found to be more sensitive than S. vulgaris to 2,4-D applications. The use of algae as bio-indicators in herbicide contaminated fresh water habitats, was discussed.

  5. Protective effect of aqueous extract from Spirulina platensis against cell death induced by free radicals

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Ammu

    2010-09-01

    Full Text Available Abstract Background Spirulina is a commercial alga well known to contain various antioxidants, especially phycocyanin. Apart from being sold as a nutraceutical, Spirulina is incorporated as a functional ingredient in food products and beverages. Most of the previous reports on antioxidant activity of Spirulina were based on chemical rather than cell-based assays. The primary objective of this study was to assess the antioxidant activity of aqueous extract from Spirulina based on its protective effect against cell death induced by free radicals. Methods The antioxidant activity of the cold water extract from food-grade Spirulina platensis was assessed using both chemical and cell-based assays. In the cell-based assay, mouse fibroblast cells (3T3 cells were incubated for 1 h in medium containing aqueous extract of Spirulina or vitamin C (positive control at 25, 125 and 250 μg/mL before the addition of 50 μM 1,1-diphenyl-2-picrylhydrazyl (DPPH or 3-ethylbenzothiazoline-6-sulfonic acid (ABTS. The cells were incubated for another 24 h before being assessed for cell death due to apoptosis using the Cell Death Detection ELISA Kit. Spectrophotometric assays based on DPPH and ABTS were also used to assess the antioxidant activity of the extract compared to vitamin C and vitamin E (positive controls. Results Spirulina extract did not cause cytotoxic effect on 3T3 cells within the range of concentrations tested (0 - 250 μg/mL. The extract reduced significantly (p Conclusions The results showed that aqueous extract of Spirulina has a protective effect against apoptotic cell death due to free radicals. The potential application of incorporating Spirulina into food products and beverages to enhance their antioxidant capacity is worth exploring.

  6. Anti-Inflammatory Effects of Spirulina platensis Extract via the Modulation of Histone Deacetylases

    Directory of Open Access Journals (Sweden)

    Tho X. Pham

    2016-06-01

    Full Text Available We previously demonstrated that the organic extract of Spirulina platensis (SPE, an edible blue-green alga, possesses potent anti-inflammatory effects. In this study, we investigated if the regulation of histone deacetylases (HDACs play a role in the anti-inflammatory effect of SPE in macrophages. Treatment of macrophages with SPE rapidly and dose-dependently reduced HDAC2, 3, and 4 proteins which preceded decreases in their mRNA levels. Degradation of HDAC4 protein was attenuated in the presence of inhibitors of calpain proteases, lysosomal acidification, and Ca2+/calmodulin-dependent protein kinase II, respectively, but not a proteasome inhibitor. Acetylated histone H3 was increased in SPE-treated macrophages to a similar level as macrophages treated with a pan-HDAC inhibitor, with concomitant inhibition of inflammatory gene expression upon LPS stimulation. Knockdown of HDAC3 increased basal and LPS-induced pro-inflammatory gene expression, while HDAC4 knockdown increased basal expression of interleukin-1β (IL-1β, but attenuated LPS-induced inflammatory gene expression. Chromatin immunoprecipitation showed that SPE decreased p65 binding and H3K9/K14 acetylation at the Il-1β and tumor necrosis factor α (Tnfα promoters. Our results suggest that SPE increased global histone H3 acetylation by facilitating HDAC protein degradation, but decreases histone H3K9/K14 acetylation and p65 binding at the promoters of Il-1β and Tnfα to exert its anti-inflammatory effect.

  7. Cultivation of Spirulina platensis by continuous process using ammonium chloride as nitrogen source

    Energy Technology Data Exchange (ETDEWEB)

    Sassano, C.E.N.; Gioielli, L.A.; Almeida, K.A.; Sato, S.; Carvalho, J.C.M. [Department of Biochemical and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes 580, Bloco 16, 05508-900 Sao Paulo-SP (Brazil); Perego, P.; Converti, A. [Department of Chemical and Process Engineering ' ' G.B. Bonino' ' , University of Genoa, via Opera Pia 15, 16145 Genoa (Italy)

    2007-08-15

    This work is focused on the influence of dilution rate (0.08{<=}D{<=}0.32 d{sup -1}) on the kinetics of continuous cultivation of Spirulina platensis at two different concentrations of ammonium chloride (N{sub 0}=1.0 and 10 mM) as nitrogen source. Cell productivity increased in both series of runs up to D{approx_equal}0.12-0.16 d{sup -1}, and then decreased. While at N{sub 0}=1.0 mM biomass washing was certainly the cause of progressive cell concentration decrease, a combination of this phenomenon with the toxic effect of excess ammonia was responsible, at N{sub 0}=10 mM and D{>=}0.20 d{sup -1}, for quick stop of cell growth just beyond the achievement of maximum cell productivity (92.4 mg l{sup -1} d{sup -1}). Similar profile was observed for protein productivity, that achieved a maximum value of 67.0 mg l{sup -1} d{sup -1}, because of the very high protein content (72.5%) of biomass produced under these conditions. The yield of nitrogen-to-biomass was much higher at the lower N{sub 0}, because of the low protein content, and reached a maximum value of 9.7 g g{sup -1} at D=0.08-0.12 d{sup -1}. The yield of nitrogen-to-protein showed less marked difference, being most of the nitrogen present in the cell as proteins or free amino-acids. (author)

  8. Neuroprotective effect of Arthrospira (Spirulina) platensis against kainic acid-neuronal death.

    Science.gov (United States)

    Pérez-Juárez, Angélica; Chamorro, Germán; Alva-Sánchez, Claudia; Paniagua-Castro, Norma; Pacheco-Rosado, Jorge

    2016-08-01

    Context Arthrospira (Spirulina) platensis (SP) is a cyanobacterium which has attracted attention because of its nutritional value and pharmacological properties. It was previously reported that SP reduces oxidative stress in the hippocampus and protects against damaging neurobehavioural effects of systemic kainic acid (KA). It is widely known that the systemic administration of KA induces neuronal damage, specifically in the CA3 hippocampal region. Objective The present study determines if the SP sub-chronic treatment has neuroprotective properties against KA. Materials and methods Male SW mice were treated with SP during 24 d, at doses of 0, 200, and 800 mg/kg, once daily, and with KA (35 mg/kg, ip) as a single dose on day 14. After the treatment, a histological analysis was performed and the number of atrophic neuronal cells in CA3 hippocampal region was quantified. Results Pretreatment with SP does not protect against seizures induced by KA. However, mortality in the SP 200 and the SP 800 groups was of 20%, while for the KA group, it was of 60%. A single KA ip administration produced a considerable neuronal damage, whereas both doses of SP sub-chronic treatment reduced the number of atrophic neurons in CA3 hippocampal region with respect to the KA group. Discussion The SP neurobehaviour improvement after KA systemic administration correlates with the capacity of SP to reduce KA-neuronal death in CA3 hippocampal cells. This neuroprotection may be related to the antioxidant properties of SP. Conclusion SP reduces KA-neuronal death in CA3 hippocampal cells.

  9. Protective effect of aqueous extract from Spirulina platensis against cell death induced by free radicals

    Science.gov (United States)

    2010-01-01

    Background Spirulina is a commercial alga well known to contain various antioxidants, especially phycocyanin. Apart from being sold as a nutraceutical, Spirulina is incorporated as a functional ingredient in food products and beverages. Most of the previous reports on antioxidant activity of Spirulina were based on chemical rather than cell-based assays. The primary objective of this study was to assess the antioxidant activity of aqueous extract from Spirulina based on its protective effect against cell death induced by free radicals. Methods The antioxidant activity of the cold water extract from food-grade Spirulina platensis was assessed using both chemical and cell-based assays. In the cell-based assay, mouse fibroblast cells (3T3) cells were incubated for 1 h in medium containing aqueous extract of Spirulina or vitamin C (positive control) at 25, 125 and 250 μg/mL before the addition of 50 μM 1,1-diphenyl-2-picrylhydrazyl (DPPH) or 3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The cells were incubated for another 24 h before being assessed for cell death due to apoptosis using the Cell Death Detection ELISA Kit. Spectrophotometric assays based on DPPH and ABTS were also used to assess the antioxidant activity of the extract compared to vitamin C and vitamin E (positive controls). Results Spirulina extract did not cause cytotoxic effect on 3T3 cells within the range of concentrations tested (0 - 250 μg/mL). The extract reduced significantly (p Spirulina has a protective effect against apoptotic cell death due to free radicals. The potential application of incorporating Spirulina into food products and beverages to enhance their antioxidant capacity is worth exploring. PMID:20858231

  10. C-phycocyanin, a very potent and novel platelet aggregation inhibitor from Spirulina platensis.

    Science.gov (United States)

    Hsiao, George; Chou, Po-Hsiu; Shen, Ming-Yi; Chou, Duen-Suey; Lin, Chien-Huang; Sheu, Joen-Rong

    2005-10-05

    The aim of this study was to systematically examine the inhibitory mechanisms of C-phycocyanin (C-PC), one of the major phycobiliproteins of Spirulina platensis (a blue-green alga), in platelet activation. In this study, C-PC concentration-dependently (0.5-10 nM) inhibited platelet aggregation stimulated by agonists. C-PC (4 and 8 nM) inhibited intracellular Ca2+ mobilization and thromboxane A2 formation but not phosphoinositide breakdown stimulated by collagen (1 microg/mL) in human platelets. In addition, C-PC (4 and 8 nM) markedly increased levels of cyclic GMP and cyclic GMP-induced vasodilator-stimulated phosphoprotein (VASP) Ser(157) phosphorylation. Rapid phosphorylation of a platelet protein of Mw 47,000 (P47), a marker of protein kinase C activation, was triggered by phorbol-12,13-dibutyrate (150 nM). This phosphorylation was markedly inhibited by C-PC (4 and 8 nM). In addition, C-PC (4 and 8 nM) markedly reduced the electron spin resonance (ESR) signal intensity of hydroxyl radicals in collagen (1 microg/mL)-activated platelets. The present study reports on a novel and very potent (in nanomolar concentrations) antiplatelet agent, C-PC, which is involved in the following inhibitory pathways: (1) C-phycocyanin increases cyclic GMP/VASP Ser157 phosphorylation and subsequently inhibits protein kinase C activity, resulting in inhibition of both P47 phosphorylation and intracellular Ca2+ mobilization, and (2) C-PC may inhibit free radicals (such as hydroxyl radicals) released from activated platelets, which ultimately inhibits platelet aggregation. These results strongly indicate that C-PC appears to represent a novel and potential antiplatelet agent for treatment of arterial thromboembolism.

  11. Construction of a Genome-Scale Metabolic Model of Arthrospira platensis NIES-39 and Metabolic Design for Cyanobacterial Bioproduction.

    Science.gov (United States)

    Yoshikawa, Katsunori; Aikawa, Shimpei; Kojima, Yuta; Toya, Yoshihiro; Furusawa, Chikara; Kondo, Akihiko; Shimizu, Hiroshi

    2015-01-01

    Arthrospira (Spirulina) platensis is a promising feedstock and host strain for bioproduction because of its high accumulation of glycogen and superior characteristics for industrial production. Metabolic simulation using a genome-scale metabolic model and flux balance analysis is a powerful method that can be used to design metabolic engineering strategies for the improvement of target molecule production. In this study, we constructed a genome-scale metabolic model of A. platensis NIES-39 including 746 metabolic reactions and 673 metabolites, and developed novel strategies to improve the production of valuable metabolites, such as glycogen and ethanol. The simulation results obtained using the metabolic model showed high consistency with experimental results for growth rates under several trophic conditions and growth capabilities on various organic substrates. The metabolic model was further applied to design a metabolic network to improve the autotrophic production of glycogen and ethanol. Decreased flux of reactions related to the TCA cycle and phosphoenolpyruvate reaction were found to improve glycogen production. Furthermore, in silico knockout simulation indicated that deletion of genes related to the respiratory chain, such as NAD(P)H dehydrogenase and cytochrome-c oxidase, could enhance ethanol production by using ammonium as a nitrogen source.

  12. Effects of oxygen and photosynthesis carbon cycle reactions on kinetics of P700 redox transients in cyanobacterium Arthrospira platensis cells.

    Science.gov (United States)

    Bolychevtseva, Yu V; Terekhova, I V; Roegner, M; Karapetyan, N V

    2007-03-01

    Effects of oxygen and photosynthesis and respiration inhibitors on the electron transport in photosystem I (PSI) of the cyanobacterium Arthrospira platensis cells were studied. Redox transients of P700 were induced by illumination at 730 nm and monitored as kinetics of the absorption changes at 810 nm; to block electron influx from PSII, the measurements were performed in the presence of 30 microM 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). Inhibitors of terminal oxidases (potassium cyanide and pentachlorophenol) insignificantly influenced the fast oxidation of P700 under aerobic conditions, whereas removal of oxygen significantly decelerated the accumulation of P700(+). In the absence of oxygen the slow oxidation of P700 observed on the first illumination was accelerated on each subsequent illumination, suggesting an activation of the carbon cycle enzymes. Under the same conditions, pentachlorophenol (an uncoupler) markedly accelerated the P700 photooxidation. Under anaerobic conditions, potassium cyanide (an inhibitor of carbon dioxide assimilation) failed to influence the kinetics of redox transients of P700, whereas iodoacetamide (an inhibitor of NADP(H)-glyceraldehyde-3-phosphate dehydrogenase) completely prevented the photooxidation of P700. Thus, the fast photooxidation of P700 in the A. platensis cells under aerobic conditions in the presence of DCMU was caused by electron transport from PSI onto oxygen, and complicated transient changes in the P700 photooxidation kinetics under anaerobic conditions (in the presence of DCMU) were due to involvement of NADP+ generated during the reducing phase of the carbon cycle.

  13. Construction of a Genome-Scale Metabolic Model of Arthrospira platensis NIES-39 and Metabolic Design for Cyanobacterial Bioproduction.

    Directory of Open Access Journals (Sweden)

    Katsunori Yoshikawa

    Full Text Available Arthrospira (Spirulina platensis is a promising feedstock and host strain for bioproduction because of its high accumulation of glycogen and superior characteristics for industrial production. Metabolic simulation using a genome-scale metabolic model and flux balance analysis is a powerful method that can be used to design metabolic engineering strategies for the improvement of target molecule production. In this study, we constructed a genome-scale metabolic model of A. platensis NIES-39 including 746 metabolic reactions and 673 metabolites, and developed novel strategies to improve the production of valuable metabolites, such as glycogen and ethanol. The simulation results obtained using the metabolic model showed high consistency with experimental results for growth rates under several trophic conditions and growth capabilities on various organic substrates. The metabolic model was further applied to design a metabolic network to improve the autotrophic production of glycogen and ethanol. Decreased flux of reactions related to the TCA cycle and phosphoenolpyruvate reaction were found to improve glycogen production. Furthermore, in silico knockout simulation indicated that deletion of genes related to the respiratory chain, such as NAD(PH dehydrogenase and cytochrome-c oxidase, could enhance ethanol production by using ammonium as a nitrogen source.

  14. A new approach to ammonium sulphate feeding for fed-batch Arthrospira (Spirulina) platensis cultivation in tubular photobioreactor.

    Science.gov (United States)

    Ferreira, Lívia S; Rodrigues, Mayla S; Converti, Attilio; Sato, Sunao; Carvalho, João Carlos M

    2010-01-01

    Arthrospira platensis was cultivated in tubular photobioreactor using different photosynthetic photon flux densities (PPFD) and protocols of (NH₄)₂SO₄ fed-batch supply. Results were evaluated by variance analysis selecting maximum cell concentration (X(m)), cell productivity (P(x)), nitrogen-to-cell conversion factor (Y(X/N)) and biomass, protein and lipid contents as responses. At PPFD of 120 and 240 μmol-photons/m² s, a parabolic profile of (NH₄)₂SO₄ addition aiming at producing biomass with 7% nitrogen content ensured X(m) values (14.1 and 12.2 g/L, respectively) comparable to those obtained with NaNO₃. At PPFD of 240 μmol-photons/m² s, P(x) (1.69 g/Ld) was 36% higher, although the photosynthetic efficiency (3.0%) was less than one-half that at PPFD of 120 μmol-photons/m² s. Biomass was shown to be constituted by about 35% proteins and 10% lipids, without any dependence on PPFD or kind of nitrogen source. These results highlight the possible use of (NH₄)₂SO₄ as alternative, cheap nitrogen source for A. platensis cultivation in tubular photobioreactors.

  15. Kinetic and growth parameters of Arthrospira (Spirulina) platensis cultivated in tubular photobioreactor under different cell circulation systems.

    Science.gov (United States)

    Ferreira, Lívia S; Rodrigues, Mayla S; Converti, Attilio; Sato, Sunao; Carvalho, João C M

    2012-02-01

    Arthrospira platensis was cultivated in tubular photobioreactor in order to evaluate growth and biomass production at variable photosynthetic photon flux density (PPFD = 60, 120, and 240 µmol photons m(-2)s(-1)) and employing three different systems for cell circulation, specifically an airlift, a motor-driven pumping and a pressurized system. The influence of these two independents variables on the maximum cell concentration (X(m)), cell productivity (P(x)), nitrogen-to-cell conversion factor (Y(X/N) ), photosynthetic efficiency (PE), and biomass composition (total lipids and proteins), taken as responses, was evaluated by analysis of variance. The statistical analysis revealed that the best combination of responses' mean values (X(m) = 4,055 mg L(-1), P(x) = 406 mg L(-1)day(-1), Y(X/N) = 5.07 mg mg(-1), total lipids = 8.94%, total proteins = 30.3%, PE = 2.04%) was obtained at PPFD = 120 µmol photons m(-2)s(-1); therefore, this light intensity should be considered as the most well-suited for A. platensis cultivation in this photobioreactor configuration. The airlift system did not exert any significant positive statistical influence on the responses, which suggests that this traditional cell circulation system could successfully be substituted by the others tested in this work.

  16. The Remedial Efficacy of Spirulina platensis versus Chromium-Induced Nephrotoxicity in Male Sprague-Dawley Rats.

    Directory of Open Access Journals (Sweden)

    M O Elshazly

    Full Text Available This study was conducted to investigate the possible protective effect of Spirulina platensis against chromium-induced nephrotoxicity. A total of 36 adult male Sprague-Dawley rats were divided into 4 equal groups (Gps. Gp1 served as control, rats of Gps 2, 3, and 4 were exposed to Spirulina platensis (300 mg/kg b.wt per os and sodium dichromate dihydrate (SDD via drinking water at concentration of 520 mg /l respectively. Chromium administration caused alterations in the renal function markers as evidenced by significant increase of blood urea and creatinine levels accompanied with significant increase in kidney's chromium residues and MDA level as well as decreased catalase activity and glutathion content in kidney tissue. Histologically, Cr provoked deleterious changes including: vascular congestion, wide spread tubular epithelium necrobiotic changes, atrophy of glomerular tuft and proliferative hyperplasia. The latter was accompanied with positive PCNA expression in kidney tissues as well as DNA ploidy interpretation of major cellular population of degenerated cells, appearance of tetraploid cells, high proliferation index and high DNA index. Morphometrical measurements revealed marked glomerular and tubular lumen alterations. On contrary, spirulina co-treatment with Cr significantly restored the histopathological changes, antioxidants and renal function markers and all the previously mentioned changes as well.

  17. The Remedial Efficacy of Spirulina platensis versus Chromium-Induced Nephrotoxicity in Male Sprague-Dawley Rats

    Science.gov (United States)

    Elshazly, M. O.; Abd El-Rahman, Sahar S.; Morgan, Ashraf M.; Ali, Merhan E.

    2015-01-01

    This study was conducted to investigate the possible protective effect of Spirulina platensis against chromium-induced nephrotoxicity. A total of 36 adult male Sprague-Dawley rats were divided into 4 equal groups (Gps). Gp1 served as control, rats of Gps 2, 3, and 4 were exposed to Spirulina platensis (300 mg/kg b.wt per os) and sodium dichromate dihydrate (SDD) via drinking water at concentration of 520 mg /l respectively. Chromium administration caused alterations in the renal function markers as evidenced by significant increase of blood urea and creatinine levels accompanied with significant increase in kidney’s chromium residues and MDA level as well as decreased catalase activity and glutathion content in kidney tissue. Histologically, Cr provoked deleterious changes including: vascular congestion, wide spread tubular epithelium necrobiotic changes, atrophy of glomerular tuft and proliferative hyperplasia. The latter was accompanied with positive PCNA expression in kidney tissues as well as DNA ploidy interpretation of major cellular population of degenerated cells, appearance of tetraploid cells, high proliferation index and high DNA index. Morphometrical measurements revealed marked glomerular and tubular lumen alterations. On contrary, spirulina co-treatment with Cr significantly restored the histopathological changes, antioxidants and renal function markers and all the previously mentioned changes as well. PMID:26029926

  18. Photosynthetic efficiency and rate of CO2 assimilation by Arthrospira (Spirulina) platensis continuously cultivated in a tubular photobioreactor.

    Science.gov (United States)

    Matsudo, Marcelo Chuei; Bezerra, Raquel Pedrosa; Sato, Sunao; Converti, Attilio; de Carvalho, João Carlos Monteiro

    2012-11-01

    Similar to other photosynthetic microorganisms, the cyanobacterium Arthrospira platensis can be used to produce pigments, single cell proteins, fatty acids (which can be used for bioenergy), food and feed supplements, and biofixation of CO(2) . Cultivation in a specifically designed tubular photobioreactor is suitable for photosynthetic biomass production, because the cultivation area can be reduced by distributing the microbial cells vertically, thus avoiding loss of ammonia and CO(2) . The aim of this study was to investigate the influence of light intensity and dilution rate on the photosynthetic efficiency and CO(2) assimilation efficiency of A. platensis cultured in a tubular photobioreactor in a continuous process. Urea was used as a nitrogen source and CO(2) as carbon source and for pH control. Steady-state conditions were achieved in most of the runs, indicating that continuous cultivation of this cyanobacterium in a tubular photobioreactor could be an interesting alternative for the large-scale fixation of CO(2) to mitigate the greenhouse effect while producing high protein content biomass.

  19. The effects of Spirulina Platensis on anthropometric indices, appetite, lipid profile and serum vascular endothelial growth factor (VEGF) in obese individuals: a randomized double blinded placebo controlled trial.

    Science.gov (United States)

    Zeinalian, Reihaneh; Farhangi, Mahdieh Abbasalizad; Shariat, Atefeh; Saghafi-Asl, Maryam

    2017-04-21

    In recent years, a great attention has been focused on Spirulina platensis as a source of potential valuable nutrients for prevention and treatment of chronic diseases. The objectives of the current study were to determine the effects of Spirulina platensis on anthropometric parameters, serum lipids, appetite and serum Vascular Endothelial Growth Factor (VEGF) in obese individuals. In the current study sixty four obese individuals aged 20-50 years were enrolled and randomly allocated into two groups of intervention and placebo. Intervention group (n = 29) received each 500 mg of the Spirulina platensis a twice-daily dosage while the control group (n = 27) received two pills daily starch for 12 weeks. Anthropometric parameters and serum VEGF and lipid profile were measured in fasting blood samples at the beginning and end of the study period. Dietary intakes were assessed by a 24-h recall method and appetite was measured using standard visual analogue scale (VAS). Body weight and body mass index (BMI) were decreased in intervention and placebo treated groups although the mean reduction in Spirulina platensis-treated group was significantly higher (P Spirulina platensis significantly reduced appetite (P = 0.008). Mean serum VEGF, low density lipoprotein-cholesterol, and triglycerides did not change significantly after intervention. Serum high density lipoprotein-cholesterol concentrations (HDL-c) significantly increased in both groups while no difference in mean difference of this change has been observed. Spirulina supplementation at a dose of 1 g/d for 12 weeks is effective in modulating body weight and appetite and partly modifies serum lipids. This can further confirm the efficacy of this herbal supplement in control and prevention of obesity and obesity- related disorders. Iranian registry of clinical trials (IRCT registration number: IRCT2015071219082N7 ; Date registered: September 12, 2015).

  20. SpirPro: A Spirulina proteome database and web-based tools for the analysis of protein-protein interactions at the metabolic level in Spirulina (Arthrospira) platensis C1

    National Research Council Canada - National Science Library

    Senachak, Jittisak; Cheevadhanarak, Supapon; Hongsthong, Apiradee

    2015-01-01

    Spirulina (Arthrospira) platensis is the only cyanobacterium that in addition to being studied at the molecular level and subjected to gene manipulation, can also be mass cultivated in outdoor ponds for commercial use as a food supplement...

  1. Scalable and thermally robust perpendicular magnetic tunnel junctions for STT-MRAM

    Science.gov (United States)

    Gottwald, M.; Kan, J. J.; Lee, K.; Zhu, X.; Park, C.; Kang, S. H.

    2015-01-01

    Thermal budget, stack thickness, and dipolar offset field control are crucial for seamless integration of perpendicular magnetic junctions (pMTJ) into semiconductor integrated circuits to build scalable spin-transfer-torque magnetoresistive random access memory. This paper is concerned with materials and process tuning to deliver thermally robust (400 °C, 30 min) and thin (i.e., fewer layers and integration-friendly) pMTJ utilizing Co/Pt-based bottom pinned layers. Interlayer roughness control is identified as a key enabler to achieve high thermal budgets. The dipolar offset fields of the developed film stacks at scaled dimensions are evaluated by micromagnetic simulations. This paper shows a path towards achieving sub-15 nm-thick pMTJ with tunneling magnetoresistance ratio higher than 150% after 30 min of thermal excursion at 400 °C.

  2. Scalable and thermally robust perpendicular magnetic tunnel junctions for STT-MRAM

    Energy Technology Data Exchange (ETDEWEB)

    Gottwald, M. [QUALCOMM Europe Incorporated, Kapeldreef 75, 3001 Heverlee (Belgium); Kan, J. J.; Lee, K.; Zhu, X.; Park, C.; Kang, S. H. [Corporate Research and Development, Qualcomm Technologies Incorporated, San Diego, California 92121-1714 (United States)

    2015-01-19

    Thermal budget, stack thickness, and dipolar offset field control are crucial for seamless integration of perpendicular magnetic junctions (pMTJ) into semiconductor integrated circuits to build scalable spin-transfer-torque magnetoresistive random access memory. This paper is concerned with materials and process tuning to deliver thermally robust (400 °C, 30 min) and thin (i.e., fewer layers and integration-friendly) pMTJ utilizing Co/Pt-based bottom pinned layers. Interlayer roughness control is identified as a key enabler to achieve high thermal budgets. The dipolar offset fields of the developed film stacks at scaled dimensions are evaluated by micromagnetic simulations. This paper shows a path towards achieving sub-15 nm-thick pMTJ with tunneling magnetoresistance ratio higher than 150% after 30 min of thermal excursion at 400 °C.

  3. Size effect in tension perpendicular to the grain

    DEFF Research Database (Denmark)

    Pedersen, Martin Bo Uhre; Clorius, Christian Odin; Damkilde, Lars;

    1999-01-01

    The strength in tension perpendicular to the grain is known to decrease with an increase in the stressed volume. Usually this size effect is explained on a stochastic basis, that is an explanation relying on an increased probability of encountering a strength reducing flaw when the volume of the ...... that the size effect can be explained on a deterministic basis. Arguments for such a simple deterministic explanation of size effect is found in finite element modelling using the orthotropic stiffness characteristics in the transverse plane of wood....

  4. Perpendicular patterned media for high density magnetic storage

    Science.gov (United States)

    Wong, Joyce Y.

    2000-11-01

    Current longitudinal thin-film media in magnetic hard- disk drives are facing an oncoming limit caused by the superparamagnetic effect, in which the individual grains in the medium become so small that they are no longer stable against thermal fluctuation. This situation is undesirable as the stored information may be lost within an unexpectedly short time frame. There have been several proposed solutions in addressing the superparamagnetic limit, and one of them is perpendicular patterned media. In this approach, a periodic array of magnetic pillars is defined lithographically on a non-magnetic substrate. Binary data of ``1'' or ``0'' can be stored in each of these elements, which have two possible magnetization directions perpendicular to the plane of the medium. In our perpendicular patterned media design, Ni columns of 150-230nm diameter with a 6:1 aspect ratio are embedded in an (AlGa)2O 3/GaAs substrate. The fabrication procedure uses a combination of high resolution electron beam lithography, dry etching, and electroplating. The high aspect ratio in the column is achieved by taking advantage of the high etching rate and selectivity of AlGaAs/GaAs over (AlGa)2O 3 in the Cl2 chemically assisted ion beam etching process. In addition to being a robust etching mask, the (AlGa)2O3 layer also plays an important role in the chemical mechanical polishing procedure to remove the overplated Ni mushrooms. Once the Ni columns are fabricated, magnetic characterization is performed using magnetic force microscopy and scanning magnetoresistance microscopy. The former measurement confirms that the electroplated Ni columns are magnetic while the latter determines whether the individual columns are stable enough to retain the recorded information. We have successfully demonstrated recording in our 170nm diameter Ni column array arranged in a square format using a commercial read/write head. This is the first demonstration of single magnetic column per bit data storage in a

  5. HITPERM soft magnetic underlayers for perpendicular thin film media

    Science.gov (United States)

    Kumar, S.; Ohkubo, T.; Laughlin, D. E.

    2002-05-01

    In this work, a class of nanocrystalline alloys, HITPERM (Fe, Co)-M-B-Cu (M=Zr, Hf, Nb, and etc.) found to exhibit excellent soft-magnetic properties in bulk were used as soft-magnetic underlayers for perpendicular thin film media. A Ti intermediate layer was used to promote a (00ṡ2) texture and exchange de-couple the magnetic layer (CoCrPt) from the soft-magnetic underlayer. Specimens were deposited at both room and elevated temperature (˜ 250 °C). The results of x-ray diffraction and transmission electron microscope structural studies, along with magnetic properties are presented.

  6. Heat Assisted Magnetization Reversal on Perpendicular Magnetized Nano-Dot

    Directory of Open Access Journals (Sweden)

    Budi Purnama

    2011-05-01

    Full Text Available Heat assisted magnetization reversal on perpendicular magnetized nano-dots has been studied by solved Landau Lifshift-Gilbert equation for magnetic recording application. The heat assisted magnetization reversal scheme has been proven to be effectively reduces threshold field down to 90 %. Otherwise, this field doesn’t depend on heating time. To understand a read-write information process, cooling time dependence of threshold field has been evaluated. As a result, the threshold field depends on the cooling time and become constant after 300 ps. This result corresponds to data transfer of Hard Disc Drive about 30 Gb/s.

  7. Spin wave spectra in perpendicularly magnetized permalloy rings

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X.; Ding, J.; Adeyeye, A. O., E-mail: eleaao@nus.edu.sg [Information Storage Materials Laboratory, Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Kostylev, M. [School of Physics, University of Western Australia, Crawley, Western Australia 6009 (Australia)

    2015-03-16

    The dynamic behavior of perpendicularly magnetized permalloy circular rings is systematically investigated as a function of film thickness using broadband field modulated ferromagnetic resonance spectroscopy. We observed the splitting of one spin wave mode into a family of dense resonance peaks for the rings, which is markedly different from the single mode observed for continuous films of the same thickness. As the excitation frequency is increased, the mode family observed for the rings gradually converges into one mode. With the increase in the film thickness, a sparser spectrum of modes is observed. Our experimental results are in qualitative agreement with the dynamic micromagnetic simulations.

  8. Coupled perpendicular magnetization in Fe/Cu/Fe trilayers

    Energy Technology Data Exchange (ETDEWEB)

    Repetto, D. [Max Planck Institut fuer Festkoerperforschung, Heisenbergstr. 1, D-70569 Stuttgart (Germany)]. E-mail: D.Repetto@fkf.mpg.de; Enders, A. [Max Planck Institut fuer Festkoerperforschung, Heisenbergstr. 1, D-70569 Stuttgart (Germany); Kern, K. [Max Planck Institut fuer Festkoerperforschung, Heisenbergstr. 1, D-70569 Stuttgart (Germany)

    2006-05-15

    Ultrathin epitaxial Fe films on Cu(1 0 0) with perpendicular magnetization have been used as templates for the preparation of FCC Fe/Cu/Fe trilayers. The magnetic anisotropy and the coupling of these films have been studied by in-situ magneto optical Kerr effect measurements and Kerr microscopy. The magnetic coupling of both Fe layers is found to be dominated by magnetostatic interaction. Adsorbate-induced spin reorientation in the top layer also causes spin reorientation in the bottom layer. The governing role of the Fe-vacuum interface for the magnetism of the whole trilayer is demonstrated.

  9. ANALYTICAL AND MATHCAD INTERSECTION BETWEEN TWO PERPENDICULAR AXES CYLINDERS

    Directory of Open Access Journals (Sweden)

    PETRESCU Ligia

    2015-06-01

    Full Text Available The intersection of two surfaces is a common line to both surfaces. This line is often called transition line. The authors propose an analytical and a computer graphics intersection between two perpendicular axes cylinders. The analytical expression of such intersection will be obtained and transposed on the development of one cylinder. The distance between the two cylinders axes is essential in the aspect of the transition line. This transition line can be also obtained, using the computer, by the MathCAD programme. Some samples are relevant in this subject, according to the distance between the cylinders.

  10. Anomalous enhancement in interfacial perpendicular magnetic anisotropy through uphill diffusion.

    Science.gov (United States)

    Das, Tanmay; Kulkarni, Prabhanjan D; Purandare, S C; Barshilia, Harish C; Bhattacharyya, Somnath; Chowdhury, Prasanta

    2014-06-17

    We observed interfacial chemical sharpening due to uphill diffusion in post annealed ultrathin multilayer stack of Co and Pt, which leads to enhanced interfacial perpendicular magnetic anisotropy (PMA). This is surprising as these elements are considered as perfectly miscible. This chemical sharpening was confirmed through quantitative energy dispersive x-ray (EDX) spectroscopy and intensity distribution of images taken on high angle annular dark field (HAADF) detector in Scanning Transmission Electron Microscopic (STEM) mode. This observation demonstrates an evidence of miscibility gap in ultrathin coherent Co/Pt multilayer stacks.

  11. Nonlinear saturation of trapped electron modes via perpendicular particle diffusion.

    Science.gov (United States)

    Merz, F; Jenko, F

    2008-01-25

    In magnetized fusion plasmas, trapped electron mode (TEM) turbulence constitutes, together with ion temperature gradient (ITG) turbulence, the dominant source of anomalous transport on ion scales. While ITG modes are known to saturate via nonlinear zonal flow generation, this mechanism is shown to be of little importance for TEM turbulence in the parameter regime explored here. Instead, a careful analysis of the statistical properties of the ExB nonlinearity in the context of gyrokinetic turbulence simulations reveals that perpendicular particle diffusion is the dominant saturation mechanism. These findings allow for the construction of a rather realistic quasilinear model of TEM induced transport.

  12. Interaction of Mutually Perpendicular Magnetic Fields in HTSC

    Directory of Open Access Journals (Sweden)

    Vasilyev Aleksandr Fedorovich

    2015-11-01

    Full Text Available In this article a problem of interaction of the crossed magnetic fields in superconductors is considered. Superconducting materials have nonlinear magnetic properties. It allows using a non-linear magnetic susceptibility for measurement of feeble magnetic fields. We place a wire of superconducting material in a constant parallel uniform magnetic field. Then we let through a wire the alternating current leak. Interaction of mutual and perpendicular variation magnetic fields, with adequate accuracy is described by Ginzburg-Landau's equations. Approximate solution of the written equations is received. The component of a magnetic field parallel to a wire contains a variable component. Frequency of a variable component of the magnetic field is equal to the doubled current frequency. Amplitude of the variable component of the magnetic field is proportional to strength of the constant magnetic field. The experimental installation for research of interaction of mutually perpendicular magnetic fields is created. The cylinder from HTSC of ceramics of the YBa2Cu3O7-x was used as a sensor. Dependence of amplitude of the second harmonica of a variation magnetic field on strength of a constant magnetic field is received.

  13. Cosmic ray acceleration at perpendicular shocks in supernova remnants

    Energy Technology Data Exchange (ETDEWEB)

    Ferrand, Gilles; Danos, Rebecca J.; Shalchi, Andreas; Safi-Harb, Samar [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB, R3T 2N2 (Canada); Edmon, Paul [Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States); Mendygral, Peter, E-mail: gferrand@physics.umanitoba.ca [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2014-09-10

    Supernova remnants (SNRs) are believed to accelerate particles up to high energies through the mechanism of diffusive shock acceleration (DSA). Except for direct plasma simulations, all modeling efforts must rely on a given form of the diffusion coefficient, a key parameter that embodies the interactions of energetic charged particles with magnetic turbulence. The so-called Bohm limit is commonly employed. In this paper, we revisit the question of acceleration at perpendicular shocks, by employing a realistic model of perpendicular diffusion. Our coefficient reduces to a power law in momentum for low momenta (of index α), but becomes independent of the particle momentum at high momenta (reaching a constant value κ{sub ∞} above some characteristic momentum p {sub c}). We first provide simple analytical expressions of the maximum momentum that can be reached at a given time with this coefficient. Then we perform time-dependent numerical simulations to investigate the shape of the particle distribution that can be obtained when the particle pressure back-reacts on the flow. We observe that for a given index α and injection level, the shock modifications are similar for different possible values of p {sub c}, whereas the particle spectra differ markedly. Of particular interest, low values of p {sub c} tend to remove the concavity once thought to be typical of non-linear DSA, and result in steep spectra, as required by recent high-energy observations of Galactic SNRs.

  14. Spirulina platensis versus silymarin in the treatment of chronic hepatitis C virus infection. A pilot randomized, comparative clinical trial

    Directory of Open Access Journals (Sweden)

    Yakoot Mostafa

    2012-04-01

    Full Text Available Abstract Background Spirulina platensis, a cynobacterium used frequently as a dietary supplement had been found to exhibit many immune-stimulating and antiviral activities. It had been found to activate macrophages, NK cells, T cells, B cells, and to stimulate the production of Interferon gamma (IFN-γ and other cytokines. Natural substances isolated from Spirulina platensis had been found to be potent inhibitors against several enveloped viruses by blocking viral absorption/penetration and some replication stages of progeny viruses after penetration into cells. We aimed to study whether this dietary supplement possesses any therapeutically feasible activity worthy of further larger controlled clinical evaluation. Methods Sixty six patients with chronic hepatitis C virus infection and eligible for inclusion had been randomized to either Spirulina or Silymarin treated groups for a period of six months treatment. The two groups were followed up and blindly compared for early (after 3 months and end of 6 months treatment virological response. The effects of both treatments on each of alanine aminotransferase (ALT, Chronic Liver Disease Questionnaire scores (CLDQ, Arizona Sexual Experience Scale scores (ASEX and the occurrence of any attributable adverse events were also compared. Results Among the 30 patients who had been treated with Spirulina and completed the 6 months protocol, 4 patients (13.3% had a complete end of treatment virological response and 2 patients (6.7% had a partial end of treatment response defined as significant decrease of virus load of at least 2-logs10. Though the proportion of responders in Spirulina group was greater than in the Silymarin group, the difference was not statistically significant at the end of both 6 months (p = 0.12 and 3 months treatment (p = 0.22 by Exact test. Alanine aminotransferase as well as CLDQ and ASEX scores were found to be more significantly improved in Spirulina than in Silymarin treated group

  15. Spirulina platensis versus silymarin in the treatment of chronic hepatitis C virus infection. A pilot randomized, comparative clinical trial

    Science.gov (United States)

    2012-01-01

    Background Spirulina platensis, a cynobacterium used frequently as a dietary supplement had been found to exhibit many immune-stimulating and antiviral activities. It had been found to activate macrophages, NK cells, T cells, B cells, and to stimulate the production of Interferon gamma (IFN-γ) and other cytokines. Natural substances isolated from Spirulina platensis had been found to be potent inhibitors against several enveloped viruses by blocking viral absorption/penetration and some replication stages of progeny viruses after penetration into cells. We aimed to study whether this dietary supplement possesses any therapeutically feasible activity worthy of further larger controlled clinical evaluation. Methods Sixty six patients with chronic hepatitis C virus infection and eligible for inclusion had been randomized to either Spirulina or Silymarin treated groups for a period of six months treatment. The two groups were followed up and blindly compared for early (after 3 months) and end of 6 months treatment virological response. The effects of both treatments on each of alanine aminotransferase (ALT), Chronic Liver Disease Questionnaire scores (CLDQ), Arizona Sexual Experience Scale scores (ASEX) and the occurrence of any attributable adverse events were also compared. Results Among the 30 patients who had been treated with Spirulina and completed the 6 months protocol, 4 patients (13.3%) had a complete end of treatment virological response and 2 patients (6.7%) had a partial end of treatment response defined as significant decrease of virus load of at least 2-logs10. Though the proportion of responders in Spirulina group was greater than in the Silymarin group, the difference was not statistically significant at the end of both 6 months (p = 0.12) and 3 months treatment (p = 0.22) by Exact test. Alanine aminotransferase as well as CLDQ and ASEX scores were found to be more significantly improved in Spirulina than in Silymarin treated group. Conclusions Our

  16. Spirulina platensis versus silymarin in the treatment of chronic hepatitis C virus infection. A pilot randomized, comparative clinical trial.

    Science.gov (United States)

    Yakoot, Mostafa; Salem, Amel

    2012-04-12

    Spirulina platensis, a cynobacterium used frequently as a dietary supplement had been found to exhibit many immune-stimulating and antiviral activities. It had been found to activate macrophages, NK cells, T cells, B cells, and to stimulate the production of Interferon gamma (IFN-γ) and other cytokines. Natural substances isolated from Spirulina platensis had been found to be potent inhibitors against several enveloped viruses by blocking viral absorption/penetration and some replication stages of progeny viruses after penetration into cells. We aimed to study whether this dietary supplement possesses any therapeutically feasible activity worthy of further larger controlled clinical evaluation. Sixty six patients with chronic hepatitis C virus infection and eligible for inclusion had been randomized to either Spirulina or Silymarin treated groups for a period of six months treatment.The two groups were followed up and blindly compared for early (after 3 months) and end of 6 months treatment virological response. The effects of both treatments on each of alanine aminotransferase (ALT), Chronic Liver Disease Questionnaire scores (CLDQ), Arizona Sexual Experience Scale scores (ASEX) and the occurrence of any attributable adverse events were also compared. Among the 30 patients who had been treated with Spirulina and completed the 6 months protocol, 4 patients (13.3%) had a complete end of treatment virological response and 2 patients (6.7%) had a partial end of treatment response defined as significant decrease of virus load of at least 2-logs10. Though the proportion of responders in Spirulina group was greater than in the Silymarin group, the difference was not statistically significant at the end of both 6 months (p = 0.12) and 3 months treatment (p = 0.22) by Exact test. Alanine aminotransferase as well as CLDQ and ASEX scores were found to be more significantly improved in Spirulina than in Silymarin treated group. Our results could suggest a therapeutically

  17. Biosorption of Zn+2 on non living biomass of Spirulina platensis immobilized on polyurethane foam cubes: Column studies

    Directory of Open Access Journals (Sweden)

    P Nirguna Babu

    2015-04-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 In the present study, the non living biomass of cyanobacteria Spirulina platensis was used for biosorption of Zn+2 in column mode. Polyurethane foam (PUF cubes were used for immobilizing the biosorbent. A maximum biomass loading of 0.2 g dry S. platensis /(g of PUF cubes could be achieved. The effect of parameters (such as pH of feed solution, flow rate of feed solution to column, bed height and initial concentration of metal ion in feed solution on uptake capacity of biosorbent was studied. A maximum uptake capacity of 87.3 mg Zn+2/(g S. platensis was observed under optimum conditions. The column was regenerated using 0.1 M HCl and sorption-desorption studies were carried out for four cycles. Both  % removal of Zn+2 and uptake capacity of biosorbent were found to progressively decrease with increase in the number of cycles. The biomass was characterized by Fourier transform infrared Spectroscopy (FTIR and Scanning Electronic Microscopic (SEM images before and after biosorption. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  18. Effect of linear alkylbenzene sulfonate on Cu(2+) removal by Spirulina platensis strain (FACHB-834).

    Science.gov (United States)

    Wang, Huili; Zhao, Xiaokai; Fang, Fang; Dahlgren, Randy A; Li, Dong; Yin, Xiaohan; Zhang, Yuna; Wang, Xuedong

    2014-10-01

    The removal efficiency of Cu(2+) by Spirulina platensis (strain FACHB-834), in viable and heat-inactivated forms, was investigated in the presence and absence of linear alkylbenzene sulfonate (LAS). When the initial Cu(2+) concentration was in the range of 0.5-1.5 mg · L(-1) , a slight increase in growth rate of FACHB-834 was observed. In contrast, when Cu(2+) or LAS concentrations were at or higher than 2.0 or 6.0 mg · L(-1) , respectively, the growth of FACHB-834 was inhibited and displayed yellowing and fragmentation of filaments. The presence of LAS improved Cu(2+) removal by ~20%, and accelerated attainment of Cu(2+) retention equilibrium. For the 2- mg · L(-1) Cu(2+) treatments, retention equilibrium occurred within 2 d and showed maximum Cu(2+) removal of 1.83 mg · L(-1) . In the presence of LAS, the ratio of extracellular bound Cu(2+) to intracellular Cu(2+) taken up by the cells was lower (1.05-2.26) than corresponding ratios (2.46-7.85) in the absence of LAS. The percentages of extracellular bound Cu(2+) to total Cu(2+) removal (both bound and taken up by cells) in the presence of LAS ranged from 51.2% to 69.3%, which was lower than their corresponding percentages (71.1%-88.7%) in the absence of LAS. LAS promoted biologically active transport of the extracellular bound form of Cu(2+) into the cell. In contrast, the addition of LAS did not increase the maximum removal efficiency of Cu(2+) (61.4% ± 5.6%) by heat-inactivated cells compared to that of living cells (59.6% ± 6.0%). These results provide a theoretical foundation for designing bioremediation strategies using FACHB-834 for use in surface waters contaminated by both heavy metals and LAS.

  19. Morfometria comparada de Triatoma infestans, T. rubrovaria e T. platensis (Hemiptera, Reduviidae, Triatominae do Uruguai Comparative Morphometry among Triatoma infestans, T. rubrovaria and T. platensis (Hemiptera, Reduviidae, Triatominae from Uruguay

    Directory of Open Access Journals (Sweden)

    Carolina M. dos Santos

    2009-03-01

    Full Text Available No Uruguai, são conhecidas 10 espécies de triatomíneos com importância epidemiológica variável, dentre as quais destacamse Triatoma infestans (Klug, 1834 e T. rubrovaria (Blanchard, 1843, consideradas as principais espécies vetoras. Triatoma platensis Neiva, 1913, apesar de ser uma espécie silvestre, pode conviver com T. infestans em galinheiros, chegando a gerar híbridos férteis. Estas três espécies fazem parte do "complexo T. infestans", formado por cinco espécies. Devido à importância epidemiológica dessas espécies no Uruguai e com a finalidade de ampliar o conjunto dos parâmetros morfológicos diferenciais destas espécies apresentamos uma abordagem morfométrica comparativa da cabeça e do pronoto. Foram medidas quatro variáveis da cabeça e quatro do pronoto a partir de 50 machos e 50 fêmeas, de cada espécie, provenientes de criação de laboratório. O programa JMP foi utilizado para as análises de Componentes Principais (ACP e Discriminante (AD. Os resultados demonstraram que os dois primeiros componentes principais (CP1 e CP2 exibem aproximadamente 77% da variação total. Os caracteres mais importantes para a distinção das espécies foram a região anteocular (RAO e a região pós-ocular (RPO, indicando que a morfometria da cabeça se mostrou mais eficiente que o pronoto para diferenciar estas espécies. A análise discriminante possibilitou separar T. platensis e T. rubrovaria mas não foi capaz de separá-las de T. infestans.In Uruguay, we can find 10 species with different epidemiological importance, amongst them we emphasize Triatoma infestans (Klug, 1834 and T. rubrovaria (Blanchard, 1843, considered main vectors. Triatoma platensis Neiva, 1913, that although being a wild species can cohabit with T. infestans in chicken coops. These three species, belong to "T. infestans complex", wich is composed by five species. Because the epidemiological importance of these species in Uruguay and, with the aim to

  20. Properties of a Bound Polaron under a Perpendicular Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We investigate the influence of a perpendicular magnetic field on a bound polaron near the interface of a polar-polar semiconductor with Rashba effect. The external magnetic field strongly changes the ground state binding energy of the polaron and the Rashba spin-orbit (SO) interaction originating from the inversion asymmetry in the heterostructure splits the ground state binding energy of the bound polaron. In this paper, we have shown how the ground state binding energy will be with the change of the external magnetic field, the location of a single impurity, the wave vector of the electron and the electron areal density, taking into account the SO coupling. Due to the presence of the phonons, whose energy gives negative contribution to the polaron's, the spin-splitting states of the bound polaron are more stable, and we find that in the condition of week magnetic field, the Zeeaman effect can be neglected.

  1. Role of Magnetosonic Solitons in Perpendicular Collisionless Shock Reformation

    Science.gov (United States)

    Gueroult, Renaud; Ohsawa, Yukiharu; Fisch, Nathaniel J.

    2017-03-01

    The nature of the magnetic structure arising from ion specular reflection in shock compression studies is examined by means of 1D particle-in-cell simulations. Propagation speed, field profiles, and supporting currents for this magnetic structure are shown to be consistent with a magnetosonic soliton. Coincidentally, this structure and its evolution are typical of foot structures observed in perpendicular shock reformation. To reconcile these two observations, we propose, for the first time, that shock reformation can be explained as the result of the formation, growth, and subsequent transition to a supercritical shock of a magnetosonic soliton. This argument is further supported by the remarkable agreement found between the period of the soliton evolution cycle and classical reformation results. This new result suggests that the unique properties of solitons can be used to shed new light on the long-standing issue of shock nonstationarity and its role on particle acceleration.

  2. Micromagnetic simulation for high field sensors with perpendicular magnetizations

    Institute of Scientific and Technical Information of China (English)

    Jin Wei; Liu Yao-Wen

    2007-01-01

    In this paper, we present a micromagnetic design for high field sensors. The hard layer of the sensors is L10-FePt which is magnetized perpendicularly to film plane and the sense layer is NiFe which is magnetized in the film plane. The magnetization configurations of the hard and sense layers at different external magnetic fields have been simulated. In micromagnetic simulation, the sense field up to one tesla can be reached by using this sensor. We find that whether the sensor has a symmetric or an asymmetric field-sensing window is determined by the coercive field of the hard layer and the demagnetizing field of the sense layer.

  3. Perpendicular magnetic anisotropy of two-dimensional Rashba ferromagnets

    Science.gov (United States)

    Kim, Kyoung-Whan; Lee, Kyung-Jin; Lee, Hyun-Woo; Stiles, M. D.

    2016-11-01

    We compute the magnetocrystalline anisotropy energy within two-dimensional Rashba models. For a ferromagnetic free-electron Rashba model, the magnetic anisotropy is exactly zero regardless of the strength of the Rashba coupling, unless only the lowest band is occupied. For this latter case, the model predicts in-plane anisotropy. For a more realistic Rashba model with finite band width, the magnetic anisotropy evolves from in-plane to perpendicular and back to in-plane as bands are progressively filled. This evolution agrees with first-principles calculations on the interfacial anisotropy, suggesting that the Rashba model captures energetics leading to anisotropy originating from the interface provided that the model takes account of the finite Brillouin zone. The results show that the electron density modulation by doping or an external voltage is more important for voltage-controlled magnetic anisotropy than the modulation of the Rashba parameter.

  4. Low coercivity giant magnetoresistance with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong-Seop; Yoon, Jungbum; Kang, Mool-Bit; You, Chun-Yeol, E-mail: cyyou@inha.ac.kr

    2014-05-01

    We find the perpendicular magnetic anisotropy giant magnetoresistance structure, whose coercivity is less than 10 Oe. We reveal that the coercivity of free layer can be smaller than 5 Oe in Co/Pd/Cu/[Co/Pd]{sub 4} multilayer structure with a TiO{sub 2} seed layer. The TiO{sub 2} seed layer plays a critical role in the small coercivity of free layer. The GMR ratio is around 1–1.8% for the out-of-plane magnetic fields, and the maximum MR sensitivity of 0.12%/Oe is achieved. - Highlights: • We find an extremely small coercivity giant magnetoresistance (GMR) structure for the out-of-plane magnetic field. • The key ingredient of small coercivity is a TiO{sub 2} seed layer. • Such a small coercivity GMR structure will be useful for automotive applications such as wheel speed, rotation, and position sensors.

  5. Manifold domain structure of double films with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Coffey, D; Diez-Ferrer, J L; Corredor, E C; Arnaudas, J I [Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Zaragoza (Spain); Ciria, M, E-mail: ciria@unizar.es [Departamento de Fisica de la Materia Condensada, Universidad de Zaragoza, Zaragoza (Spain)

    2011-03-23

    We present epitaxial structures made of twin nickel blocks with perpendicular magnetic anisotropy separated by a copper layer which, for some values of this interleaving layer, show domain structures with four levels of contrast in magnetic force microscopy images. This manifold domain structure implies that the magnetization in the Ni blocks, in addition to the parallel orientation, undergoes a non-collinear configuration with respect to each other. To explain this result we consider a magnetoelastic domain structure with M in the plane that can elude the clamping done by the substrate with an average strain of -42 x 10{sup -6} ({approx}70% of the bulk value). Thus, the out-of-plane anisotropy is balanced and a biquadratic exchange coupling can stabilize the non-collinear domain configurations between the Ni blocks.

  6. Nonstationarity of a two-dimensional perpendicular shock: Competing mechanisms

    Science.gov (United States)

    Lembège, Bertrand; Savoini, Philippe; Hellinger, Petr; Trávníček, Pavel M.

    2009-03-01

    Two-dimensional particle-in-cell (PIC) simulations are used for analyzing in detail different nonstationary behaviors of a perpendicular supercritical shock. A recent study by Hellinger et al. (2007) has shown that the front of a supercritical shock can be dominated by the emission of large-amplitude whistler waves. These waves inhibit the self-reformation driven by the reflected ions; then, the shock front appears almost ``quasi-stationary.'' The present study stresses new complementary results. First, for a fixed β i value, the whistler waves emission (WWE) persists for high M A above a critical Mach number (i.e., M A >= M A WWE). The quasi-stationarity is only apparent and disappears when considering the full 3-D field profiles. Second, for lower M A , the self-reformation is retrieved and becomes dominant as the amplitude of the whistler waves becomes negligible. Third, there exists a transition regime in M A within which both processes compete each other. Fourth, these results are observed for a strictly perpendicular shock only as B 0 is within the simulation plane. When B 0 is out of the simulation plane, no whistler waves emission is evidenced and only self-reformation is recovered. Fifth, the occurrence and disappearance of the nonlinear whistler waves are well recovered in both 2-D PIC and 2-D hybrid simulations. The impacts on the results of the mass ratio (2-D PIC simulations), of the resistivity and spatial resolution (2-D hybrid simulations), and of the size of the simulation box along the shock front are analyzed in detail.

  7. Evaluation of fuel properties for microalgae Spirulina platensis bio-diesel and its blends with Egyptian petro-diesel

    Directory of Open Access Journals (Sweden)

    Soha S.M. Mostafa

    2017-05-01

    In this study, the feasibility of biodiesel production from microalga Spirulina platensis has been investigated. The physico–chemical characteristics of the produced biodiesel were studied according to the standards methods of analysis (ASTM and evaluated according to their fuel properties as compared to Egyptian petro-diesel. Blends of microalgae biodiesel and petro-diesel (B2, B5, B10 and B20 were prepared on a volume basis and their physico–chemical characteristics have been also studied. The obtained results showed that; with the increase of biodiesel concentration in the blends; the viscosity, density, total acid number, initial boiling point, calorific value, flash point, cetane number and diesel index increase. While the pour point, cloud point, carbon residue and sulfur, ash and water contents decrease. The observed properties of the blends were within the recommended petro-diesel standard specifications and they are in favor of better engine performance.

  8. Cultivation of Arthrospira (spirulina) platensis in desalinator wastewater and salinated synthetic medium: protein content and amino-acid profile.

    Science.gov (United States)

    Volkmann, Harriet; Imianovsky, Ulisses; Oliveira, Jorge L B; Sant'anna, Ernani S

    2008-01-01

    Arthrospira (Spirulina) platensis was cultivated in laboratory under controlled conditions (30°C, photoperiod of 12 hours light/dark provided by fluorescent lamps at a light intensity of 140 μmol photons.m(-2).s(-1) and constant bubbling air) in three different culture media: (1) Paoletti medium (control), (2) Paoletti supplemented with 1 g.L(-1) NaCl (salinated water) and (3) Paoletti medium prepared with desalinator wastewater. The effects of these treatments on growth, protein content and amino acid profile were measured. Maximum cell concentrations observed in Paoletti medium, Paoletti supplemented with salinated water or with desalinator wastewater were 2.587, 3.545 and 4.954 g.L(-1), respectively. Biomass in medium 3 presented the highest protein content (56.17%), while biomass in medium 2 presented 48.59% protein. All essential amino acids, except lysine and tryptophan, were found in concentrations higher than those requiried by FAO.

  9. Purification, crystallization and preliminary crystallographic investigations of selenium-containing phycocyanin from se-lenium-rich algae (Spirulina platensis)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The selenium-containing phycocyanin from the selenium-rich algae (Spirulina platensis) has been crystallized in two crystal forms by the hanging-drop vapor diffusion techniques. A chromatographic procedure of gel filtration and anion exchange was used for purification. Form I crystal with space group P21 and cell parameters a =108.0 ?, b = 117.0 ?, c = 184.0 ?, b = 90.2° and 12(ab) units in the asymmetric unit was obtained by using (NH4)2SO4 as precipitant. These crystals diffract up to 2.8 ?. Form II crystal obtained by using PEG4000 as precipitant belongs to space group P63 with unit cell constants a = 155.0 ?, c = 40.3 ?, g =120.0° and one(ab) unit in the asymmetric unit. The crystals diffract beyond 2.9 ?. The possible stacking forms of phycocyanin molecules in the first crystal form were discussed.

  10. Utilização de rejeito de dessalinizador como meio de cultura alternativo para cultivo de Arthrospira (Spirulina) platensis

    OpenAIRE

    Volkmann, Harriet

    2006-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Ciência dos Alimentos. Este estudo teve como objetivo a utilização de rejeito de dessalinizador no cultivo de Arthrospira platensis, cultivada em fotobiorreatores de 4 L, sob condições laboratoriais controladas de 30°C, iluminação de 140 µmol.m-2.s-1, fotoperíodo de 12 horas claro/escuro e insuflação constante de ar atmosférico. Utilizaram-se os seguintes meios de cult...

  11. Summer feeding ecology of Great Pampa-finches, Embernagra platensis at Laguna de Guaminí, Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Laura M. Ferman

    2010-09-01

    Full Text Available The aim of this study was to assemble data on the summer feeding ecology of the Great Pampa-finch, Embernagra platensis at the Laguna de Guaminí, Buenos Aires, Argentina, and to explore the differences related to the dietary patterns for each sex between winter and summer when possible. The stomach contents of 43 birds were analyzed. The animal fraction was composed of Hymenoptera (45.1%, Coleoptera (32.4%, Lepidoptera (6.0%, Araneae (5% and Orthoptera (3.2%. The application of the index of relative importance (IRI resulted in 1490.4 for Coleoptera, 428.5 for Hymenoptera and 162.5 for Lepidoptera caterpillars. The vegetal fraction consisted of Triticum aestivum (26.9%, Cyperaceous (25%, Poaceae (Gramineae (19.3% and Panicum sp. (11.2%. The IRI values were 893.8 for Triticum aestivum, 174.5 for Gramineae, 126.5 for Panicum sp. and 112.8 for Scirpus sp. The food niche width was 0.33 for both sexes; the diversity index resulted in 1.06 for females and 1.33 for males and specific diversity ranged from 1.87 to 2.84. A canonical component analysis (CCA was performed on environmental and morphometric variables, and a Monte Carlo test confirmed the canonical correlations. A t-test showed that some birds harmonized with a logarithmic model and some with a geometric curve. During the summer, Embernagra platensis ingests Hymenoptera and Coleoptera more often than seeds, suggesting that two biological mechanisms could be taking place in this bird.O objetivo deste estudo foi reunir dados referentes à ecologia alimentar do Sabiá-do-banhado, Embernagra platensis, na laguna de Guaminí, Buenos Aires, Argentina, e explorar as diferenças relacionadas aos padrões dietéticos para cada sexo entre inverno e verão, quando possível. O conteúdo estomacal de 43 pássaros foi analisado. A fração animal foi composta por Hymenoptera (45,1%, Coleoptera (32,4%, Lepidoptera(6,0%, Araneae (5% e Orthoptera (3,2%. A aplicação do índice de importância relativa (IRI

  12. Alkaline shift effect on the uptake of germanium by algae, Chlorella ellipsoideae, Oscillatoria sp. and Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Yanagimoto, M. (National Food Research Inst., Ibaraki, Japan); Saitoh, H.; Kakimoto, N.

    1983-01-01

    The uptake of germanium (Ge) by microalgae was interesting because of a therapeutic effect of organic germanium. In the case of blue green algae, Oscillatoria sp. and Spirulina platensis, satisfactory amounts of Ge were accumulated in the cells, where the pH of the culture was shifted to 11.8 or 12.3, after sufficient growth. These algae could hardly grow in a culture at pH 11.8 or pH 12.3. In the case of Chlorella ellipsoideae, a good result could not be obtained. But a relatively high uptake of Ge into the cells could be obtained in the culture shifted to pH 8.6, in which the alga could hardly grow. Although the effective pHs are different, the effect of the elevated pH of the cultures can be called an alkaline shift effect from the same feature.

  13. Effect of Initial nitrite concentration on growth of spirulina platensis; Supirurina no zoshoku ni oyobosu ashosan ion shonodo no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Ohira, Y.; Obata, E.; Kuga, Y.; Ando, K. [Muroran Inst. of Tech., Hokkaido (Japan). Dept. of Applied Chemistry; Yamada, S.

    2000-09-10

    The effect of the initial nitrite concentration on the growth of S. platensis was experimentally investigated using the medium added to the sodium nitrite of 0.0-1.6 kg{center_dot}m{sup -3}. When the initial nitrite concentration is smaller than 0.8 kg{center_dot}m{sup -3}, the growth rate is greater than that without nitrite. The specific growth rate had the maximum value and is approximately 1.3 times that of a standard medium when the range of the initial nitrite concentration is 0.3-0.4 kg{center_dot}m{sup -3}. When the initial nitrite concentration is greater than 0.8 kg{center_dot}m{sup -3}, the growth rate was smaller than that of a standard medium due to nitrite inhibition. (author)

  14. The Production of High Purity Phycocyanin by Spirulina platensis Using Light-Emitting Diodes Based Two-Stage Cultivation.

    Science.gov (United States)

    Lee, Sang-Hyo; Lee, Ju Eun; Kim, Yoori; Lee, Seung-Yop

    2016-01-01

    Phycocyanin is a photosynthetic pigment found in photosynthetic cyanobacteria, cryptophytes, and red algae. In general, production of phycocyanin depends mainly on the light conditions during the cultivation period, and purification of phycocyanin requires expensive and complex procedures. In this study, we propose a new two-stage cultivation method to maximize the quantitative content and purity of phycocyanin obtained from Spirulina platensis using red and blue light-emitting diodes (LEDs) under different light intensities. In the first stage, Spirulina was cultured under a combination of red and blue LEDs to obtain the fast growth rate until reaching an absorbance of 1.4-1.6 at 680 nm. Next, blue LEDs were used to enhance the concentration and purity of the phycocyanin in Spirulina. Two weeks of the two-stage cultivation of Spirulina yielded 1.28 mg mL(-1) phycocyanin with the purity of 2.7 (OD620/OD280).

  15. Replacement value of blue-green alga (Spirulina platensis) for fishmeal and a vitamin-mineral premix for broiler chicks.

    Science.gov (United States)

    Venkataraman, L V; Somasekaran, T; Becker, E W

    1994-07-01

    1. The effect of sun-dried Spirulina platensis in poultry diets was studied in a 12-week feeding trial by replacing either fishmeal (FM) or groundnut cake (GC) in a commercial diet with algae at isonitrogenous concentrations of 140 g/kg and 170 g/kg respectively. Additional vitamins/minerals were omitted from the algal diets because Spirulina is rich in them. 2. Efficiency of food utilisation, protein efficiency ratio and dressing percentage indicated that substitution of FM or GC by alga did not affect the performance of broilers. 3. None of the diets affected the weights, compositions and histopathology of the various organs of the chicks. 4. Meat quality remained unchanged except for a more intense colour in the case of birds fed on the alga-containing diets.

  16. Single step aqueous two-phase extraction for downstream processing of C-phycocyanin from Spirulina platensis.

    Science.gov (United States)

    Chethana, S; Nayak, Chetan A; Madhusudhan, M C; Raghavarao, K S M S

    2015-04-01

    C-phycocyanin, a natural food colorant, is gaining importance worldwide due to its several medical and pharmaceutical applications. In the present study, aqueous two-phase extraction was shown to be an attractive alternative for the downstream processing of C-phycocyanin from Spirulina platensis. By employing differential partitioning, C-phycocyanin selectively partitioned to the polymer rich (top) phase in concentrated form and contaminant proteins to the salt rich (bottom) phase. This resulted in an increase in the product purity (without losing much of the yield) in a single step without the need of multiple processing steps. Effect of process parameters such as molecular weight, tie line length, phase volume ratio, concentration of phase components on the partitioning behavior of C-phycocyanin was studied. The results were explained based on relative free volume of the phase systems. C-phycocyanin with a purity of 4.32 and yield of about 79 % was obtained at the standardized conditions.

  17. CO₂ from alcoholic fermentation for continuous cultivation of Arthrospira (Spirulina) platensis in tubular photobioreactor using urea as nitrogen source.

    Science.gov (United States)

    Matsudo, Marcelo C; Bezerra, Raquel P; Converti, Attilio; Sato, Sunao; Carvalho, João Carlos M

    2011-01-01

    Carbon dioxide released from alcoholic fermentation accounts for 33% of the whole CO(2) involved in the use of ethanol as fuel derived from glucose. As Arthrospira platensis can uptake this greenhouse gas, this study evaluates the use of the CO(2) released from alcoholic fermentation for the production of Arthrospira platensis. For this purpose, this cyanobacterium was cultivated in continuous process using urea as nitrogen source, either using CO(2) from alcoholic fermentation, without any treatment, or using pure CO(2) from cylinder. The experiments were carried out at 120 μmol photons m(-2) s(-1) in tubular photobioreactor at different dilution rates (0.2 ≤ D ≤ 0.8 d(-1) ). Using CO(2) from alcoholic fermentation, maximum steady-state cell concentration (2661 ± 71 mg L(-1) ) was achieved at D = 0.2 d(-1) , whereas higher dilution rate (0.6 d(-1) ) was needed to maximize cell productivity (839 mg L(-1) d(-1) ). This value was 10% lower than the one obtained with pure CO(2) , and there was no significant difference in the biomass protein content. With D = 0.8 d(-1) , it was possible to obtain 56% ± 1.5% and 50% ± 1.2% of protein in the dry biomass, using pure CO(2) and CO(2) from alcoholic fermentation, respectively. These results demonstrate that the use of such cost free CO(2) from alcoholic fermentation as carbon source, associated with low cost nitrogen source, may be a promising way to reduce costs of continuous cultivation of photosynthetic microorganisms, contributing at the same time to mitigate the greenhouse effect.

  18. In Situ TEM Scratch Testing of Perpendicular Magnetic Recording Multilayers with a Novel MEMS Tribometer

    Science.gov (United States)

    Hintsala, Eric D.; Stauffer, Douglas D.; Oh, Yunje; Asif, S. A. Syed

    2017-01-01

    Utilizing a newly developed two-dimensional (2D) transducer designed for in situ transmission electron microscope (TEM) nanotribology, deformation mechanisms of a perpendicular magnetic recording film stack under scratch loading conditions were evaluated. These types of films are widely utilized in storage devices, and loss of data by grain reorientation in the recording layers is of interest. The observed deformation was characterized by a stick-slip mechanism, which was induced by a critical ratio of lateral to normal force regardless of normal force. At low applied normal forces, the diamond-like carbon (DLC) coating and asperities in the recording layer were removed during scratching, while, at higher applied forces, grain reorientation and debonding of the recording layer was observed. As the normal force and displacement were increased, work for stick-slip deformation and contact stress were found to increase based upon an Archard's Law analysis. These experiments also served as an initial case study demonstrating the capabilities of this new transducer.

  19. Equilibrium, thermodynamic and kinetic studies for the biosorption of aqueous lead(II), cadmium(II) and nickel(II) ions on Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Seker, Ayseguel [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: aysegulseker@iyte.edu.tr; Shahwan, Talal [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: talalshahwan@iyte.edu.tr; Eroglu, Ahmet E. [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: ahmeteroglu@iyte.edu.tr; Yilmaz, Sinan [Department of Chemistry, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)], E-mail: sinanyilmaz@iyte.edu.tr; Demirel, Zeliha [Department of Biology, Ege University, Bornova 35100, Izmir (Turkey)], E-mail: zelihademirel@gmail.com; Dalay, Meltem Conk [Department of Bioengineering, Ege University, Bornova 35100, Izmir (Turkey)], E-mail: meltemconkdalay@gmail.com

    2008-06-15

    The biosorption of lead(II), cadmium(II) and nickel(II) ions from aqueous solution by Spirulina platensis was studied as a function of time, concentration, temperature, repetitive reactivity, and ionic competition. The kinetic results obeyed well the pseudo second-order model. Freundlich, Dubinin Radushkevich and Temkin isotherm models were applied in describing the equilibrium partition of the ions. Freundlich isotherm was applied to describe the design of a single-stage batch sorption system. According to the thermodynamic parameters such as {delta}G{sup o}, {delta}H{sup o}and {delta}S{sup o} calculated, the sorption process was endothermic and largely driven towards the products. Sorption activities in a three metal ion system were studied which indicated that there is a relative selectivity of the biosorbent towards Pb{sup 2+} ions. The measurements of the repetitive reusability of S. platensis indicated a large capacity towards the three metal ions.

  20. Experimental Substantiation of the Possibility of Developing Selenium- and Iodine-Containing Pharmaceuticals Based on Blue-Green Algae Spirulina Platensis

    CERN Document Server

    Mosulishvili, L M; Belokobylsky, A I; Khisanishvili, L A; Frontasyeva, M V; Pavlov, C C; Gundorina, S F

    2001-01-01

    The great potential of using blue-green algae Spirulina platensis as a matrix for the production of selenium- and iodine-containing pharmaceuticals is shown experimentally. The background levels of 31 major, minor and trace elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni (using -reaction), As, Br, Zn, Rb, Mo, Ag, Sb, I, Ba, Sm, Tb, Tm, Hf, Ta, W, Au, Hg, Th) in Spirulina platensis biomass were determined by means of epithermal neutron activation analysis. The dependence of selenium and iodine accumulation in spirulina biomass on a nutrient medium loding of the above elements was characterised. To demonstrate the possibilities of determining toxic element intake by spirulina biomass, mercury was selected. The technological parameters for production of iodinated treatment-and-prophylactic pills are developed.

  1. Perpendicular magnetization of CoFeB on top of an amorphous buffer layer

    Science.gov (United States)

    Kim, Dongseok; Jung, K. Y.; Joo, Sungjung; Jang, Youngjae; Hong, Jinki; Lee, B. C.; You, C. Y.; Cho, J. H.; Kim, M. Y.; Rhie, K.

    2015-01-01

    Perpendicular magnetic anisotropy was observed in sputtered FeZr/CoFeB/MgO multilayers. A thin paramagnetic amorphous FeZr layer was used as a buffer layer and perpendicular anisotropy was obtained by annealing the samples without an external magnetic field. The critical CoFeB thickness for perpendicular anisotropy was 1.8 nm; the anisotropy changes from out-of-plane to in-plane as the CoFeB thickness increases beyond this point. Perpendicular anisotropy was also enhanced when a Ta layer was capped on top of the MgO layer. The amorphous buffer provided better perpendicular anisotropy than previously reported Ta buffer, and it may be applied to perpendicular magnetization MRAM devices where good uniformity of tunnel junctions is required.

  2. Halotolerant/alkalophilic bacteria associated with the cyanobacterium Arthrospira platensis (Nordstedt Gomont that promote early growth in Sorghum bicolor (L. Moench

    Directory of Open Access Journals (Sweden)

    Gómez G. Liliana Cecilia

    2012-04-01

    Full Text Available

    Arthrospira platensis associated bacteria (APAB identified through molecuar biology like Bacillus okhensis, Indibacter alkaliphilus and Halomonas sp., are also producing 3-indol acetic acid (IAA, these bacteria was used in early plant growth promotion tests over Sorghum bicolor, these bioassay was considered indirect evidence to suggest that APAB also may have stimulatory effects over A. platensis growth naturally. I. alkaliphilus and B. okhensis enhanced early germination of S. bicolor seads, with better results than that achieved by Azospirillum brasilense, bacterium used like reference as a common plant growth promoting rizobacteria. The three APAB enhanced significative differences (P≤0.05 over morphoagronomic parameters, I. alkaliphilus and B. okhensis exhibit better resoults in elongation stimulation and root and foliage dry weight. Above evidence suggest this bacteria like plant growth promoting and it recomended testing with A. platensis axenic cultures and its associated bactteri for understanding true interaction between them.

  3. Development of cassava cake enriched with its own bran and Spirulina platensis - doi: 10.4025/actascitechnol.v34i4.10687

    Directory of Open Access Journals (Sweden)

    Meire Franci Polonio Navacchi

    2012-10-01

    Full Text Available The cassava cake was developed enriching it with a biomass of Spirulina platensis and a type of bran made out of its own starch. This biomass, a part from being rich in protein, also contains vitamins, essential fatty acids and minerals. Around Umuarama, in the State of Paraná, there is an agricultural/industrial complex annually producing and processing tons of cassava. Baked goods can be elaborated based in cassava as a way to expand the use of this raw material and to produce food free of gluten to celiac people. In this complex a solid byproduct is generated, which is rich in starch and fibres, and because of its low commercial value it is used for animal feed or discarded. The bran was dehydrated and analysed microbiologically as well as physically and chemically so as to be used in applied research. Developed energetic food based on cassava lacks protein, but this can be supplied by adding the biomass of Spirulina platensis. Different formulations of this cassava cake were developed varying the concentration of Spirulina platensis and cassava bran. The formulation that presented the best features received chocolate before being submitted to sensory tests by children in the public education system. The results show an excellent acceptance which made viable the development of this product because of aspects like nutrition, technology and sensorial.

  4. Lyase activities of heterologous CpcS and CpcT for phycocyanin holo-β-subunit from Arthrospira platensis in Escherichia coli

    Science.gov (United States)

    Yi, Junjie; Xu, Di; Zang, Xiaonan; Yuan, Dingyang; Zhao, Bingran; Tang, Li; Tan, Yanning; Zhang, Xuecheng

    2014-06-01

    Arthrospira platensis is an economically important cyanobacterium; and it has been used widely in food and pharmaceutical industries. The phycocyanin (PC) from A. platensis is extremely valuable in medicine and molecular biology due to its antioxidation and anti-tumoring activity and applicability as fluorescence protein tag. In present study, two recombinant plasmids, one contained the phycocyanobilin (PCB)-producing genes ( hox1 and pcyA) while the other contained the phycobiliprotein gene ( cpcB) and the lyase gene (either cpcS/U or cpcT), were constructed and synchronically transferred into E. coli in order to test the the activities of relevant lyases for catalysing PCB addition to CpcB during synthesizing fluorescent PC holo-β-subunit (β-PC) of A. platensis. As was evidenced by the fluorescence emitted at a peak specific for PC, CpcB was successfully synthesized in E. coli, to which co-expressed PCBs attached though at a relatively low efficiency. The results showed that the attachment of PCBs to CpcB were carried out mainly by co-expressed CpcS/U but CpcB also showed some autocatalytic activity. Currently, no CpcT activity was detected in this E. coli expression system. Further studies will be conducted to improve the efficiency of fluorescent PC synthesis in E. coli.

  5. D1 protein turnover is involved in protection of Photosystem II against UV-B induced damage in the cyanobacterium Arthrospira (Spirulina) platensis.

    Science.gov (United States)

    Wu, Hongyan; Abasova, Leyla; Cheregi, Otilia; Deák, Zsuzsanna; Gao, Kunshan; Vass, Imre

    2011-01-01

    By using two strains of Arthrospira (Spirulina)platensis, an economically important filamentous cyanobacterium, we compared the impairment of PSII activity and loss of D1 protein content under UV-B radiation. Our study showed that UV-B radiation induced a gradual loss of the oxygen-evolving activity to about 56% after 180 min UV-B irradiation both in strains 439 and D-0083, which have been kept under indoor and an outdoor culturing conditions, respectively for a prolonged period of time. The loss of oxygen evolution was accelerated in both strains in the presence of lincomycin, an inhibitor of protein synthesis, and the amount of D1 protein showed a decrease comparable to that of oxygen evolution during the UV-B exposure. However, the UV-B induced loss of oxygen-evolving activity and D1 protein amount was largely prevented when A. platensis cells were exposed to UV-B irradiance supplemented with visible light. Comparison of the two strains also showed a smaller extent of D1 protein synthesis dependent PSII repair in the indoor strain. Our results show that turnover of the D1 protein is an important defense mechanism to counteract the UV-B induced damage of PSII in A. platensis, and also that visible light plays an important role in maintaining the function of PSII under simultaneous exposure to UV-B and visible light.

  6. Lyase Activities of Heterologous CpcS and CpcT for Phycocyanin Holo-β-subunit from Arthrospira platensis in Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    YI Junjie; XU Di; ZANG Xiaonan; YUAN Dingyang; ZHAO Bingran; TANG Li; TAN Yanning; ZHANG Xuecheng

    2014-01-01

    Arthrospira platensis is an economically important cyanobacterium;and it has been used widely in food and pharmaceu-tical industries. The phycocyanin (PC) from A. platensis is extremely valuable in medicine and molecular biology due to its anti-oxidation and anti-tumoring activity and applicability as fluorescence protein tag. In present study, two recombinant plasmids, one contained the phycocyanobilin (PCB)-producing genes (hox1 and pcyA) while the other contained the phycobiliprotein gene (cpcB) and the lyase gene (either cpcS/U or cpcT), were constructed and synchronically transferred into E. coli in order to test the the activi-ties of relevant lyases for catalysing PCB addition to CpcB during synthesizing fluorescent PC holo-β-subunit (β-PC) of A. platensis. As was evidenced by the fluorescence emitted at a peak specific for PC, CpcB was successfully synthesized in E. coli, to which co-expressed PCBs attached though at a relatively low efficiency. The results showed that the attachment of PCBs to CpcB were carried out mainly by co-expressed CpcS/U but CpcB also showed some autocatalytic activity. Currently, no CpcT activity was de-tected in this E. coli expression system. Further studies will be conducted to improve the efficiency of fluorescent PC synthesis in E. coli.

  7. EFFECTS OF ATHROSPIRA PLATENSIS, MONODORA MYRISTICA AND HELIANTHUS ANNUUS ON THE RATE OF POLYMERIZATION, SICKLE CELL REVERSION AND OXYGEN AFFINITY OF SICKLE CELL HEMOGLOBIN

    Directory of Open Access Journals (Sweden)

    Nwaichi E. O.

    2013-08-01

    Full Text Available The in vitro effects of the cyanobacteria (Athrospira platensis, spices (Monodora myristica and the achene (Hellianthus annuus on the rate of polymerization, sickle cell reversion and oxygen affinity of sickle cell hemoglobin (HbS was studied spectophotometrically using hemolysates of HbS containing erythrocytes treated with sodium metabisulphite in the presence of the different plant extracts. All fractions of the three plant extracts showed statistically significant decreases (p< 0.05 in the rate of polymerization therefore inhibited the rate of sickling with increasing time. The Benzene Soluble Extract (BESE fraction of Hellianthus annuus demonstrated the highest antisickling activity (89.15% inhibition of HbSS, while the least was by the BESE fraction of Athrospira platensis (45.16% inhibition of HbSS. The crude aqueous extract (CAE fraction of Athrospira platensis showed the highest anti-oxidant effect, while CAE fraction of Monodora myristica gave the least. The water soluble extract (WSE fraction of Hellianthus annuus expressed maximum rate of sickling reversion. Alcohol extracts of these plants were found to exhibit a more significant antisickling activity relative to the aqueous extracts which is attributable to the presence of some lipophillic amino acids present in the alcoholic fraction of the extracts, and it could also be responsible for the observed high reversion capacity but low antioxidant effect of the lipophillic fraction of the plant extracts.

  8. Rapid Mutation of Spirulina platensis by a New Mutagenesis System of Atmospheric and Room Temperature Plasmas (ARTP) and Generation of a Mutant Library with Diverse Phenotypes

    Science.gov (United States)

    Zhang, Chong; Tan, Yinyee; Jiang, Peixia; Ge, Nan; Heping Li; Xing, Xinhui

    2013-01-01

    In this paper, we aimed to improve the carbohydrate productivity of Spirulina platensis by generating mutants with increased carbohydrate content and growth rate. ARTP was used as a new mutagenesis tool to generate a mutant library of S. platensis with diverse phenotypes. Protocol for rapid mutation of S. platensis by 60 s treatment with helium driven ARTP and high throughput screening method of the mutants using the 96-well microplate and microplate reader was established. A mutant library of 62 mutants was then constructed and ideal mutants were selected out. The characteristics of the mutants after the mutagenesis inclined to be stable after around 9th subculture, where the total mutation frequency and positive mutation frequency in terms of specific growth rate reached 45% and 25%, respectively. The mutants in mutant library showed diverse phenotypes in terms of cell growth rate, carbohydrate content and flocculation intensity. The positive mutation frequency in terms of cellular carbohydrate content with the increase by more than 20% percent than the wild strain was 32.3%. Compared with the wild strain, the representative mutants 3-A10 and 3-B2 showed 40.3% and 78.0% increase in carbohydrate content, respectively, while the mutant 4-B3 showed 10.5% increase in specific growth rate. The carbohydrate contents of the representative mutants were stable during different subcultures, indicating high genetic stability. ARTP was demonstrated to be an effective and non-GMO mutagenesis tool to generate the mutant library for multicellular microalgae. PMID:24319517

  9. Efecto de carbón tipo lignito sobre el crecimiento y producción de pigmentos de Arthrospira platensis

    Directory of Open Access Journals (Sweden)

    Massiel Vanesa Rivera Gonzalez

    2016-05-01

    Full Text Available The Biomass production and pigments from Arthrospira platensis has become very important, because these have applications in food production, metabolites of biotechnological and industrial products. However, for the production of biomass and pigments they have been used various substrates that generate high costs. Growth and pigment production A. platensis under the influence of six concentrations of low rank coal (LRC type lignite (10, 20, 30, 40, 50, 60 mg / L was tested against a concentration of AIA (80 mg / L, in batch cultures, performed in Zarrouk medium supplemented with LRC type lignite and AIA, under constant aeration and photoperiod of 12:12 hours, for 33 days. The highest average values obtained in terms of biomass production and pigments were achieved in the cultures supplemented with 50 and 60 mg/L of LRC type lignite with respect to the controls. The results provide evidence of the potential use of CBR as humified organic matter, rich in nutrients for growing A. platensis that could be tapped into aquifers means they are exposed to coal mining, contributing to processes of purification and bioremediation of contaminated waters carboniferous materials.

  10. Rapid mutation of Spirulina platensis by a new mutagenesis system of atmospheric and room temperature plasmas (ARTP and generation of a mutant library with diverse phenotypes.

    Directory of Open Access Journals (Sweden)

    Mingyue Fang

    Full Text Available In this paper, we aimed to improve the carbohydrate productivity of Spirulina platensis by generating mutants with increased carbohydrate content and growth rate. ARTP was used as a new mutagenesis tool to generate a mutant library of S. platensis with diverse phenotypes. Protocol for rapid mutation of S. platensis by 60 s treatment with helium driven ARTP and high throughput screening method of the mutants using the 96-well microplate and microplate reader was established. A mutant library of 62 mutants was then constructed and ideal mutants were selected out. The characteristics of the mutants after the mutagenesis inclined to be stable after around 9(th subculture, where the total mutation frequency and positive mutation frequency in terms of specific growth rate reached 45% and 25%, respectively. The mutants in mutant library showed diverse phenotypes in terms of cell growth rate, carbohydrate content and flocculation intensity. The positive mutation frequency in terms of cellular carbohydrate content with the increase by more than 20% percent than the wild strain was 32.3%. Compared with the wild strain, the representative mutants 3-A10 and 3-B2 showed 40.3% and 78.0% increase in carbohydrate content, respectively, while the mutant 4-B3 showed 10.5% increase in specific growth rate. The carbohydrate contents of the representative mutants were stable during different subcultures, indicating high genetic stability. ARTP was demonstrated to be an effective and non-GMO mutagenesis tool to generate the mutant library for multicellular microalgae.

  11. Resolving the controversy of a possible relationship between perpendicular magnetic anisotropy and the magnetic damping parameter

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Justin M.; Nembach, Hans T.; Silva, T. J. [National Institute of Standards and Technology, Electromagnetics Division, Boulder, Colorado 80305 (United States)

    2014-08-11

    We use broadband ferromagnetic resonance spectroscopy to systematically measure the Landau-Lifshitz damping parameter, perpendicular anisotropy, and the orbital moment asymmetry in Co{sub 90}Fe{sub 10}/Ni multilayers. No relationship is found between perpendicular magnetic anisotropy and the damping parameter in this material. However, inadequate accounting for inhomogeneous linewidth broadening, spin-pumping, and two-magnon scattering could give rise to an apparent relationship between anisotropy and damping. In contrast, the orbital-moment asymmetry and the perpendicular anisotropy are linearly proportional to each other. These results demonstrate a fundamental mechanism by which perpendicular anisotropy can be varied independently of the damping parameter.

  12. Second order anisotropy contribution in perpendicular magnetic tunnel junctions.

    Science.gov (United States)

    Timopheev, A A; Sousa, R; Chshiev, M; Nguyen, H T; Dieny, B

    2016-06-01

    Hard-axis magnetoresistance loops were measured on perpendicular magnetic tunnel junction pillars of diameter ranging from 50 to 150 nm. By fitting these loops to an analytical model, the effective anisotropy fields in both free and reference layers were derived and their variations in temperature range between 340 K and 5 K were determined. It is found that a second-order anisotropy term of the form -K2cos(4)θ must be added to the conventional uniaxial -K1cos(2)θ term to explain the experimental data. This higher order contribution exists both in the free and reference layers. At T = 300 K, the estimated -K2/K1 ratios are 0.1 and 0.24 for the free and reference layers, respectively. The ratio is more than doubled at low temperatures changing the ground state of the reference layer from "easy-axis" to "easy-cone" regime. The easy-cone regime has clear signatures in the shape of the hard-axis magnetoresistance loops. The existence of this higher order anisotropy was also confirmed by ferromagnetic resonance experiments on FeCoB/MgO sheet films. It is of interfacial nature and is believed to be due to spatial fluctuations at the nanoscale of the first order anisotropy parameter at the FeCoB/MgO interface.

  13. Switching Properties of sub-100 nm Perpendicular Magnetic Tunnel Junctions

    Science.gov (United States)

    Tryputen, Larysa; Piotrowski, Stephan; Bapna, Mukund; Chien, Chia-Ling; Wang, Weigang; Majetich, Sara; Ross, Caroline

    2015-03-01

    Perpendicular magnetic tunnel junctions (p-MTJs) have great potential for realizing high-density non-volatile memory and logic devices. It is critical to solve scalability problem to implement such devices, to achieve low resistance area and to reduce switching current density while maintaining thermal stability. We present our recent results on fabrication of high resolution Ta/CoFeB/MgO/CoFeB/Ta p-MTJ devices and characterization of their switching properties as well as topography and current mapping by using nanoscale Conductive Atomic Force Microscopy. Our patterning method is based on using hydrogen silsesquioxane resist mask combined with ion beam etching. It allows to fabricate p-MTJ devices down to 40 nm in diameter while maintaining the magnetic quality of the multilayers. Repeatable, consistent switching behaviour has been observed in the obtained p-MTJ devices of 500 nm down to 40 nm with 10 - 800 mV voltage applied. Switching field increased as device diameter decreased, from 580 Oe at 500 nm (MR = 10%) to 410 Oe at 80 nm (MR = 9%). We discuss the effect of device sizes on the switching properties. This work was supported in part by C-SPIN, one of the six centers of STARnet, a Semiconductor Research Corporation Program sponsored by MARCO and DARPA and in part through the National Science Foundation through NCN-Needs Program, Contract 12207020-EEC.

  14. Highly Efficient Domain Walls Injection in Perpendicular Magnetic Anisotropy Nanowire.

    Science.gov (United States)

    Zhang, S F; Gan, W L; Kwon, J; Luo, F L; Lim, G J; Wang, J B; Lew, W S

    2016-04-21

    Electrical injection of magnetic domain walls in perpendicular magnetic anisotropy nanowire is crucial for data bit writing in domain wall-based magnetic memory and logic devices. Conventionally, the current pulse required to nucleate a domain wall is approximately ~10(12) A/m(2). Here, we demonstrate an energy efficient structure to inject domain walls. Under an applied electric potential, our proposed Π-shaped stripline generates a highly concentrated current distribution. This creates a highly localized magnetic field that quickly initiates the nucleation of a magnetic domain. The formation and motion of the resulting domain walls can then be electrically detected by means of Ta Hall bars across the nanowire. Our measurements show that the Π-shaped stripline can deterministically write a magnetic data bit in 15 ns even with a relatively low current density of 5.34 × 10(11) A/m(2). Micromagnetic simulations reveal the evolution of the domain nucleation - first, by the formation of a pair of magnetic bubbles, then followed by their rapid expansion into a single domain. Finally, we also demonstrate experimentally that our injection geometry can perform bit writing using only about 30% of the electrical energy as compared to a conventional injection line.

  15. Effect of soft underlayer magnetic anisotropy on perpendicular recording process

    Science.gov (United States)

    Lim, C. K.; Kim, E. S.; Yoon, S. Y.; Kong, S. H.; Lee, H. S.; Oh, H. S.; Kim, Y. S.

    2007-03-01

    The presence of the soft magnetic underlayer (SUL) in perpendicular magnetic recording (PMR) media is essential for the application. It is commonly understood that the SUL provides the return flux path and enhances the writing field by enhancing the recording field from the write pole. However, SUL increases the magnetic noise during the read back process due to magnetic domain walls in the SUL. Hence, it is common to grow SUL with large uniaxial or unidirectional magnetic anisotropy field ( H k) to reduce domain wall noise. In this paper, we explore the effect of increasing SUL H k on the recording process. We studied this effect by using the finite element micromagnetic simulation. Our simulation results show that the contribution of SUL to the writing field amplitude is reduced with increasing H k. This reduction in magnetic field from high H k SUL actually improves the recording performance due to the better field gradient at SUL. The simulation results are qualitatively consistent with the actual experimental data obtained from the Guzik measurement.

  16. Artificially engineered Heusler ferrimagnetic superlattice exhibiting perpendicular magnetic anisotropy

    Science.gov (United States)

    Ma, Q. L.; Zhang, X. M.; Miyazaki, T.; Mizukami, S.

    2015-01-01

    To extend density limits in magnetic recording industry, two separate strategies were developed to build the storage bit in last decade, introduction of perpendicular magnetic anisotropy (PMA) and adoption of ferrimagnetism/antiferromagnetism. Meanwhile, these properties significantly improve device performance, such as reducing spin-transfer torque energy consumption and decreasing signal-amplitude-loss. However, materials combining PMA and antiferromagnetism rather than transition-metal/rare-earth system were rarely developed. Here, we develop a new type of ferrimagnetic superlattice exhibiting PMA based on abundant Heusler alloy families. The superlattice is formed by [MnGa/Co2FeAl] unit with their magnetizations antiparallel aligned. The effective anisotropy (Kueff) over 6 Merg/cm3 is obtained, and the SL can be easily built on various substrates with flexible lattice constants. The coercive force, saturation magnetization and Kueff of SLs are highly controllable by varying the thickness of MnGa and Co2FeAl layers. The SLs will supply a new choice for magnetic recording and spintronics memory application such as magnetic random access memory.

  17. Electric field scales at quasi-perpendicular shocks

    Directory of Open Access Journals (Sweden)

    S. N. Walker

    2004-07-01

    Full Text Available This paper investigates the short scale structures that are observed in the electric field during crossings of the quasi-perpendicular bow shock using data from the Cluster satellites. These structures exhibit large amplitudes, as high as 70 m Vm-1 and so make a significant contribution to the overall change in potential at the shock front. It is shown that the scale size of these short-lived electric field structures is of the order of a few cpe. The relationships between the scale size and the upstream Mach number and θBn are studied. It is found that the scale size of these structures decreases with increasing plasma β and as θBn→90°. The amplitude of the spikes remains fairly constant with increasing Ma and appears to increase as θBn→90°.

  18. Cross-scale coupling at a perpendicular collisionless shock

    CERN Document Server

    Umeda, Takayuki; Yamazaki, Ryo; 10.1016/j.pss.2010.01.007

    2011-01-01

    A full particle simulation study is carried out on a perpendicular collisionless shock with a relatively low Alfven Mach number (M_A=5). In the present study, we have performed a two-dimensional (2D) electromagnetic full particle simulation with a "shock-rest-frame model". The simulation domain is taken to be larger than the ion inertial length in order to include full kinetics of both electrons and ions. The present simulation result has confirmed the transition of shock structures from the cyclic self-reformation to the quasi-stationary shock front. During the transition, electrons and ions are thermalized in the direction parallel to the shock magnetic field. Ions are thermalized by low-frequency electromagnetic waves (or rippled structures) excited by strong ion temperature anisotropy at the shock foot, while electrons are thermalized by high-frequency electromagnetic waves (or whistler mode waves) excited by electron temperature anisotropy at the shock overshoot. Ion acoustic waves are also excited at th...

  19. Tunnel Junction with Perpendicular Magnetic Anisotropy: Status and Challenges

    Directory of Open Access Journals (Sweden)

    Mengxing Wang

    2015-08-01

    Full Text Available Magnetic tunnel junction (MTJ, which arises from emerging spintronics, has the potential to become the basic component of novel memory, logic circuits, and other applications. Particularly since the first demonstration of current induced magnetization switching in MTJ, spin transfer torque magnetic random access memory (STT-MRAM has sparked a huge interest thanks to its non-volatility, fast access speed, and infinite endurance. However, along with the advanced nodes scaling, MTJ with in-plane magnetic anisotropy suffers from modest thermal stability, high power consumption, and manufactural challenges. To address these concerns, focus of research has converted to the preferable perpendicular magnetic anisotropy (PMA based MTJ, whereas a number of conditions still have to be met before its practical application. This paper overviews the principles of PMA and STT, where relevant issues are preliminarily discussed. Centering on the interfacial PMA in CoFeB/MgO system, we present the fundamentals and latest progress in the engineering, material, and structural points of view. The last part illustrates potential investigations and applications with regard to MTJ with interfacial PMA.

  20. Artificially engineered Heusler ferrimagnetic superlattice exhibiting perpendicular magnetic anisotropy.

    Science.gov (United States)

    Ma, Q L; Zhang, X M; Miyazaki, T; Mizukami, S

    2015-01-19

    To extend density limits in magnetic recording industry, two separate strategies were developed to build the storage bit in last decade, introduction of perpendicular magnetic anisotropy (PMA) and adoption of ferrimagnetism/antiferromagnetism. Meanwhile, these properties significantly improve device performance, such as reducing spin-transfer torque energy consumption and decreasing signal-amplitude-loss. However, materials combining PMA and antiferromagnetism rather than transition-metal/rare-earth system were rarely developed. Here, we develop a new type of ferrimagnetic superlattice exhibiting PMA based on abundant Heusler alloy families. The superlattice is formed by [MnGa/Co2FeAl] unit with their magnetizations antiparallel aligned. The effective anisotropy (K(u)(eff)) over 6 Merg/cm(3) is obtained, and the SL can be easily built on various substrates with flexible lattice constants. The coercive force, saturation magnetization and K(u)(eff) of SLs are highly controllable by varying the thickness of MnGa and Co2FeAl layers. The SLs will supply a new choice for magnetic recording and spintronics memory application such as magnetic random access memory.

  1. Highly Efficient Domain Walls Injection in Perpendicular Magnetic Anisotropy Nanowire

    Science.gov (United States)

    Zhang, S. F.; Gan, W. L.; Kwon, J.; Luo, F. L.; Lim, G. J.; Wang, J. B.; Lew, W. S.

    2016-04-01

    Electrical injection of magnetic domain walls in perpendicular magnetic anisotropy nanowire is crucial for data bit writing in domain wall-based magnetic memory and logic devices. Conventionally, the current pulse required to nucleate a domain wall is approximately ~1012 A/m2. Here, we demonstrate an energy efficient structure to inject domain walls. Under an applied electric potential, our proposed Π-shaped stripline generates a highly concentrated current distribution. This creates a highly localized magnetic field that quickly initiates the nucleation of a magnetic domain. The formation and motion of the resulting domain walls can then be electrically detected by means of Ta Hall bars across the nanowire. Our measurements show that the Π-shaped stripline can deterministically write a magnetic data bit in 15 ns even with a relatively low current density of 5.34 × 1011 A/m2. Micromagnetic simulations reveal the evolution of the domain nucleation – first, by the formation of a pair of magnetic bubbles, then followed by their rapid expansion into a single domain. Finally, we also demonstrate experimentally that our injection geometry can perform bit writing using only about 30% of the electrical energy as compared to a conventional injection line.

  2. Engineered Heusler Ferrimagnets with a Large Perpendicular Magnetic Anisotropy

    Directory of Open Access Journals (Sweden)

    Reza Ranjbar

    2015-09-01

    Full Text Available Synthetic perpendicular magnetic anisotropy (PMA ferrimagnets consisting of 30-nm-thick D022-MnGa and Co2MnSi (CMS cubic Heusler alloys with different thicknesses of 1, 3, 5, 10 and 20 nm, buffered and capped with a Cr film, are successfully grown epitaxially on MgO substrate. Two series samples with and without post annealing at 400 °C are fabricated. The (002 peak of the cubic L21 structure of CMS films on the MnGa layer is observed, even for the 3-nm-thick CMS film for both un-annealed and annealed samples. The smaller remnant magnetization and larger switching field values of CMS (1–20 nm/MnGa (30 nm bilayers compared with 30-nm-thick MnGa indicates antiferromagnetic (AFM interfacial exchange coupling (Jex between MnGa and CMS films for both un-annealed and annealed samples. The critical thickness of the CMS film for observing PMA with AFM coupling in the CMS/MnGa bilayer is less than 10 nm, which is relatively large compared to previous studies.

  3. Two-Channel Metal Detector Using Two Perpendicular Antennas

    Directory of Open Access Journals (Sweden)

    Kyoo Nam Choi

    2014-01-01

    Full Text Available Two-channel metal detector, having two sets of perpendicularly oriented sensor antennas, is proposed to expand detectable size, ranging from mm through cm scale, of metal sensor, while conventional metal sensor is dedicated for detection only in mm or cm scale. The characteristics of the two metal detection sensor channels were investigated, respectively, and the interference effect, while in simultaneous operation, between two sensor channels was discussed. Metal detection channel, having sensitivity in mm scale, showed detectable sensitivity to moving ferrous sphere, with diameter down to 0.7 mm, at 50 kHz exciting frequency and enhanced sensitivity distribution. And metal detection channel having sensitivity in cm scale showed more uniform sensitivity distribution with the flexibility for future modular construction. The effect of interference, while in simultaneous operation of two sensors, resulted in reduced output response, but still within usable detection range. Thus it was feasible to operate two sensors, having different sensitivity range, simultaneously and to extend detection range from mm to cm scale, within practically acceptable interference.

  4. Axially perpendicular offset Raman scheme for reproducible measurement of housed samples in a noncircular container under variation of container orientation.

    Science.gov (United States)

    Duy, Pham K; Chang, Kyeol; Sriphong, Lawan; Chung, Hoeil

    2015-03-17

    An axially perpendicular offset (APO) scheme that is able to directly acquire reproducible Raman spectra of samples contained in an oval container under variation of container orientation has been demonstrated. This scheme utilized an axially perpendicular geometry between the laser illumination and the Raman photon detection, namely, irradiation through a sidewall of the container and gathering of the Raman photon just beneath the container. In the case of either backscattering or transmission measurements, Raman sampling volumes for an internal sample vary when the orientation of an oval container changes; therefore, the Raman intensities of acquired spectra are inconsistent. The generated Raman photons traverse the same bottom of the container in the APO scheme; the Raman sampling volumes can be relatively more consistent under the same situation. For evaluation, the backscattering, transmission, and APO schemes were simultaneously employed to measure alcohol gel samples contained in an oval polypropylene container at five different orientations and then the accuracies of the determination of the alcohol concentrations were compared. The APO scheme provided the most reproducible spectra, yielding the best accuracy when the axial offset distance was 10 mm. Monte Carlo simulations were performed to study the characteristics of photon propagation in the APO scheme and to explain the origin of the optimal offset distance that was observed. In addition, the utility of the APO scheme was further demonstrated by analyzing samples in a circular glass container.

  5. UTILIZAÇÃO DE Spirulina platensis COMO SUPLEMENTO ALIMENTAR DURANTE A REVERSÃO SEXUAL DA TILÁPIA-DO-NILO (VAR. CHITRALADA EM ÁGUA SALINA

    Directory of Open Access Journals (Sweden)

    Ricardo Lafaiete Moreira

    2011-03-01

    Full Text Available This study aimed to evaluate the Spirulina platensis influence as a food supplement in Nile tilapia post-larvae grown in saline water. The experiment consisted of two treatments with three replicates. In first one the animals were fed ration containing the androgen 17 α - methyltestosterone and S. platensis, and in the other only diet with the hormone. At the end of the reversal (28 days, tilapia that received S. platensis showed average weights of 1.17 ± 0.16 g, significantly superior to the animals fed only ration, which reached an average weight of 0.62 ± 0.38 g (P < 0.05; however, survival rates showed no significant difference (P < 0.05. At the end of the experiment (78 days, fish gonadal analysis showed indices of 47.5% of males for fish reared without microalgae and 59.09% for fish reared with S. platensis. It was conclude that Nile tilapia showed good growth and survival rate in the presence of S. platensis, compared to the fish fed only diet in saline water. However, it was not possible to obtain acceptable rates of sex reversal after the administration of masculinizing hormone through the diet.

  6. THE FUNCTION OF FTSZ IN MORPHOGENESIS OF SPIRULINA PLATENSIS%FtsZ在钝顶螺旋藻形态建成中的作用

    Institute of Scientific and Technical Information of China (English)

    邹路阳; 吴娟; 曾群安; 徐虹

    2012-01-01

    为了研究细胞骨架蛋白FtsZ在螺旋藻形态建成中的作用,通过PCR克隆了ftsZ基因并进行原核表达,对表达的融合蛋白进行了纯化.通过免疫小鼠制备了FtsZ的多克隆抗体.分别用Western blot和免疫荧光技术检测螺旋藻不同形态藻丝体中ftsZ的表达和定位.结果表明,在两株不同螺旋藻Spirulina platensis FACHB869和FACHB882中,ftsZ在直线形藻丝体中的表达量都高于螺旋形藻丝体.免疫荧光定位结果显示,FtsZ蛋白在藻细胞中呈环状分布于细胞膜上,且这种环状结构在直线形藻丝体中排列较密而在螺旋形藻丝体中排列疏松.ftsZ在不同形态藻丝体中的表达量和细胞定位差异说明,细胞骨架蛋白FtsZ可能通过改变细胞刚性而参与螺旋藻形态建成.%To explore the function of prokaryotic cytoskeleton protein FtsZ in morphogenesis of Spirulina platensis, the gene encoding FtsZ was cloned into pET-28a vector and highly expressed in E. coli BL21. The target protein purified by affinity chromatography was used to immunize mice to prepare polyclonal antibodies. The differences in expression and localization of FtsZ between linear and spiral forms of Spirulina platensis were determined by western blot and im-munofluorescence respectively. Both the results of western blotting from two strains of Spirulian plantensis showed that the expression level of Ftsz in linear algal trichomes was higher than that of spiral forms. FtsZ were localized underneath the cell membrane at the future division site, forming a ring-like structure known as the Z-ring. The Z-ring distributed more tightly in linear forms than that in spiral forms. The differences in expression and localization of FtsZ between linear and spiral forms of Spirulina platensis mean that cytoskeleton FtsZ probably plays an important role in morphogenesis of Spirulina platensis.

  7. Pareto utility

    NARCIS (Netherlands)

    Masako, I.; Laeven, R.J.A.; Magnus, J.R.; Muris, C.

    2013-01-01

    In searching for an appropriate utility function in the expected utility framework, we formulate four properties that we want the utility function to satisfy. We conduct a search for such a function, and we identify Pareto utility as a function satisfying all four desired properties. Pareto utility

  8. Cultivo da cianobactéria Spirulina platensis a partir de efluente sintético de suíno Culture of the cyanobacteria Spirulina platensis using synthetic swine wastewater

    Directory of Open Access Journals (Sweden)

    Tanise Boeira Pelegrini Bertolin

    2005-02-01

    Full Text Available Estudou-se o cultivo da cianobactéria Spirulina platensis utilizando-se efluente sintético de suíno a fim de avaliar o crescimento das cepas LEB 52 e PARACAS dessa cianobactéria, em função da diluição do meio (0 e 50% e da concentração de bicarbonato de sódio (0 e 3g/L. Nesta etapa foi utilizado um Planejamento Fatorial Completo 2³. Na Segunda etapa, diluiu-se o meio em 80, 50 e 20% e utilizou-se um Planejamento Fatorial Multiníveis 3¹ x 2¹. Os cultivos foram realizados a 30°C, com fotoperíodo de 12 horas. As variáveis utilizadas como resposta nas duas etapas foram a concentração máxima de biomassa e a velocidade específica máxima de crescimento, sendo os resultados avaliados mediante de Análise de Variância. Na primeira etapa, os maiores valores de concentração celular, 0,55 g/L, foram obtidos com a cepa LEB-52 em efluente sintético diluído a 50% em água destilada e sem a adição de bicarbonato de sódio, como suplementação da fonte de carbono. Na otimização da diluição, o maior valor de concentração celular foi de 0,35 g/L utilizando-se cepa PARACAS e diluição de 80%. As duas cepas estudadas de Spirulina platensis podem crescer em efluente sintético de suíno e o seu crescimento é favorecido pela diluição do meio.The growth of LEB-52 and PARACAS strains of Spirulina platensis cyanobacteria was studied using synthetic swine wastewater. The effects of medium dilution (0 and 50% and sodium bicarbonate addition to the medium (0 and 3g/L were initially investigated. In this step, it was used a complete Factorial Planning 2³. In the second step, the medium was diluted at 80, 50 and 20% and it was used a Factorial Planning 3¹x2¹. The cultivation was carried out at 30°C, with photophase of 12 hours. The maximum biomass concentration and maximum specific growth rate were assessed, with the results being evaluated through Analysis of Variance. In first step, the greater biomass concentration (0.55g/L was

  9. Secondary School Mathematics, Chapter 13, Perpendiculars and Parallels (I), Chapter 14, Similarity. Student's Text.

    Science.gov (United States)

    Stanford Univ., CA. School Mathematics Study Group.

    The first chapter of the seventh unit in this SMSG series discusses perpendiculars and parallels; topics covered include the relationship between parallelism and perpendicularity, rectangles, transversals, parallelograms, general triangles, and measurement of the circumference of the earth. The second chapter, on similarity, discusses scale…

  10. Aplicación de estrategias nutricionales y su efecto en el crecimiento en el cultivo continuo de Spirulina (Arthrospira platensis Application of nutritional strategies and their effect in continuous culture of Spirulina (Arthrospira platensis

    Directory of Open Access Journals (Sweden)

    Elizabet Rojas

    2012-09-01

    Full Text Available Se realizó un cultivo continuo de Spirulina (Arthrospira platensis durante 78 días en un fotobiorreactor tubular de 300 L de volumen. Durante este periodo se registró el crecimiento en biomasa y la respuesta del cultivo a la estrategia de adición del medio nutritivo. Utilizando como base el medio Zarrouk modificado, se elaboraron tres medios: medio inicial (MI, medio crecimiento (SA1+SA2 y medio mantenimiento (SB1+SB2 para las distintas etapas del cultivo. La entrega de los medios se efectuó paulatinamente y de acuerdo a los requerimientos del crecimiento en biomasa (en peso seco diario del cultivo. La biomasa inicial del cultivo fue de 2,0 g L-1, al día 20 se efectuó la primera cosecha parcial (50% dando inicio a una nueva etapa del cultivo con una biomasa inicial de 1,7 g L-1, 20 días después se realizó una segunda cosecha parcial del cultivo, iniciando una tercera etapa de cultivo con una biomasa de 1,6 g L-1. Los resultados obtenidos al cabo de las cosechas fueron, en promedio, de 3,7; 4,1 y 9,7 g L-1, respectivamente. El análisis proximal efectuado al final del cultivo continuo indicó un 71,6% de proteína.A continuous culture of Spirulina (Arthrospira platensis was performed for 78 in a tubular photobioreactor of 300 L volume. During this period there was growth in biomass and crop response to the strategy of adding the nutrient medium. Using as a basis the modified Zarrouk medium, three nutritive combinations were elaborated: initial medium (MI, growth medium (SA1+SA2 and maintenance medium (SB1+SB2 for different crop stages. The media delivery is affected gradually and in accordance with requirements of growing biomass (dry weight daily cultivation. The initial crop biomass was 2.0 g L-1, on day 20 of culture was made the first partial harvest (50% starting a new stage of the crop with an initial biomass of 1.7 g L-1' 20 days after a second crop was partially culture initiating a third culture step with a biomass of 1.6 g L-1

  11. Culture Conditions stimulating high γ-Linolenic Acid accumulation by Spirulina platensis Condições de cultura simulando o levado acúmulo de ácido γ-linolênico por Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Srinivasa Reddy Ronda

    2008-12-01

    Full Text Available Gamma-linolenic acid (GLA production by Spirulina platensis under different stress-inducing conditions was studied. Submerged culture studies showed that low temperature (25ºC, strong light intensity (6 klux and primrose oil supplement (0.8%w/v induced 13.2 mg/g, 14.6 mg/g and 13.5 mg linolenic acid per gram dry cell weight respectively. A careful observation of fatty acid profile of the cyanobacteria shows that, oleic acid and linoleic acid, in experiments with varying growth temperature and oil supplements respectively, helped in accumulating excess γ-linolenic acid. In addition, cultures grown at increasing light regimes maintained the γ-linolenic acid to the total fatty acid ratio(GLA/TFA constant, despite any change in γ-linolenic acid content of the cyanobacteria.Estudou-se a produção de ácido γ-linolênico por Spirulina platensis em diferentes condições de estresse. Culturas submersas indicaram que temperatura baixa (25ºC, forte intensidade de luz (6 klux e suplementação com óleo de prímula (0,8% p/v induziram a produção de ácido linolênico de 13,2 mg/g, 14,6 mg/g e 13,5 mg/g peso seco, respectivamente. Uma observação cuidadosa do perfil de ácidos graxos da cianobacteria indica que os ácidos oléico e linoléico, em experimentos com diferentes temperaturas de crescimento e suplementos de óleo, auxiliaram no acúmulo de excesso de ácido γ-linolênico. Além disso, as culturas obtidas em intensidades crescentes de luz mantiveram a relação ácido γ-linolênico/ácidos graxos totais constante, independentemente de qualquer mudança no conteúdo de ácido γ-linolênico da cianobactéria.

  12. Laser-driven, magnetized quasi-perpendicular collisionless shocks on the Large Plasma Device

    Energy Technology Data Exchange (ETDEWEB)

    Schaeffer, D. B., E-mail: dschaeffer@physics.ucla.edu; Everson, E. T.; Bondarenko, A. S.; Clark, S. E.; Constantin, C. G.; Vincena, S.; Van Compernolle, B.; Tripathi, S. K. P.; Gekelman, W.; Niemann, C. [Department of Physics and Astronomy, University of California - Los Angeles, Los Angeles, California 90095 (United States); Winske, D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-05-15

    The interaction of a laser-driven super-Alfvénic magnetic piston with a large, preformed magnetized ambient plasma has been studied by utilizing a unique experimental platform that couples the Raptor kJ-class laser system [Niemann et al., J. Instrum. 7, P03010 (2012)] to the Large Plasma Device [Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] at the University of California, Los Angeles. This platform provides experimental conditions of relevance to space and astrophysical magnetic collisionless shocks and, in particular, allows a detailed study of the microphysics of shock formation, including piston-ambient ion collisionless coupling. An overview of the platform and its capabilities is given, and recent experimental results on the coupling of energy between piston and ambient ions and the formation of collisionless shocks are presented and compared to theoretical and computational work. In particular, a magnetosonic pulse consistent with a low-Mach number collisionless shock is observed in a quasi-perpendicular geometry in both experiments and simulations.

  13. Molecular Cloning of cpcU and Heterodimeric Bilin Lyase Activity Analysis of CpcU and CpcS for Attachment of Phycocyanobilin to Cys-82 on the β-Subunit of Phycocyanin in Arthrospira platensis FACHB314

    Directory of Open Access Journals (Sweden)

    Fei Wu

    2016-03-01

    Full Text Available A new bilin lyase gene cpcU was cloned from Arthrospira platensis FACHB314 to study the assembly of the phycocyanin β-Subunit. Two recombinant plasmids, one contained the phycocyanobilin (PCB producing genes (hoxI and pcyA, while the other contained the gene of the β-Subunit of phycobiliprotein (cpcB and the lyase gene (cpcU, cpcS, or cpcU/S were constructed and separately transferred into Escherichia coli in order to test the activities of relevant lyases for catalyzing PCB addition to CpcB during synthesizing fluorescent β-PC of A. platensis FACHB314. The fluorescence intensity examination showed that Cys-82 maybe the active site for the β-Subunit binding to PCBs and the attachment could be carried out by CpcU, CpcS, or co-expressed cpcU/S in A. platensis FACHB314.

  14. Molecular Cloning of cpcU and Heterodimeric Bilin Lyase Activity Analysis of CpcU and CpcS for Attachment of Phycocyanobilin to Cys-82 on the β-Subunit of Phycocyanin in Arthrospira platensis FACHB314.

    Science.gov (United States)

    Wu, Fei; Zang, Xiaonan; Zhang, Xuecheng; Zhang, Ran; Huang, Xiaoyun; Hou, Lulu; Jiang, Minjie; Liu, Chang; Pang, Chunhong

    2016-03-16

    A new bilin lyase gene cpcU was cloned from Arthrospira platensis FACHB314 to study the assembly of the phycocyanin β-Subunit. Two recombinant plasmids, one contained the phycocyanobilin (PCB) producing genes (hoxI and pcyA), while the other contained the gene of the β-Subunit of phycobiliprotein (cpcB) and the lyase gene (cpcU, cpcS, or cpcU/S) were constructed and separately transferred into Escherichia coli in order to test the activities of relevant lyases for catalyzing PCB addition to CpcB during synthesizing fluorescent β-PC of A. platensis FACHB314. The fluorescence intensity examination showed that Cys-82 maybe the active site for the β-Subunit binding to PCBs and the attachment could be carried out by CpcU, CpcS, or co-expressed cpcU/S in A. platensis FACHB314.

  15. Mutant strains of Spirulina (Arthrospira) platensis to increase the efficiency of micro-ecological life support systems

    Science.gov (United States)

    Brown, Igor

    The European Micro-Ecological Life Support System Alternative (MELiSSA) is an advanced idea for organizing a bioregenerative system for long term space flights and extraterrestrial settlements (Hendrickx, De Wever et al., 2005). Despite the hostility of both lunar and Martian environments to unprotected life, it seems possible to cultivate photosynthetic bacteria using closed bioreactors illuminated and heated by solar energy. Such reactors might be employed in critical processes, e.g. air revitalization, foodcaloric and protein source, as well as an immunomodulators production. The MELiSSA team suggested cyanobacterium Spirulina as most appropriate agent to revitalize air and produce a simple "fast" food. This is right suggestion because Spirulina was recently shown to be an oxygenic organism with the highest level of O2 production per unit mass (Ananyev et al., 2005). Chemical composition of Spirulina includes proteins (55Aiming to make Spirulina cultivation in life support systems like MELiSSA more efficient, we selected Spirulina mutant strains with increased fraction of methionine in the biomass of this cyanobacterium and compared the effect of parental wild strain of Spirulina and its mutants on the tendency of such experimental illnesses as radiationinduced lesions and hemolythic anemia. Results: It was found that mutant strains 198B and 27G contain higher quantities of total protein, essential amino acids, c-phycocyanin, allophycocyanin and chlorophyll a than parental wild strain of S. platensis. The strain 198B is also characterized with increased content of carotenoids. Revealed biochemical peculiarities of mutant strains suggest that these strains can serve as an additional source of essential amino acids as well as phycobiliproteins and carotenoids for the astronauts. Feeding animals suffering from radiation-induced lesions, c-phycocyanin, extracted from strain 27G, led to a correction in deficient dehydrogenase activity and energy-rich phosphate levels

  16. Perpendicular magnetization of CoFeB on top of an amorphous buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongseok; Jung, K.Y. [Department of Display and Semiconductor Physics, Korea University, Sejong 339-700 (Korea, Republic of); Joo, Sungjung [Department of Display and Semiconductor Physics, Korea University, Sejong 339-700 (Korea, Republic of); Center for Electricity and Magnetism, Korea Research Institute of Standard and Science, Daejeon 305-340 (Korea, Republic of); Jang, Youngjae; Hong, Jinki [Department of Display and Semiconductor Physics, Korea University, Sejong 339-700 (Korea, Republic of); Lee, B.C.; You, C.Y.; Cho, J.H. [Department of Physics, Inha University, Incheon 402-751 (Korea, Republic of); Kim, M.Y. [Department of Nano Physics, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Rhie, K., E-mail: krhie@korea.ac.kr [Department of Display and Semiconductor Physics, Korea University, Sejong 339-700 (Korea, Republic of)

    2015-01-15

    Perpendicular magnetic anisotropy was observed in sputtered FeZr/CoFeB/MgO multilayers. A thin paramagnetic amorphous FeZr layer was used as a buffer layer and perpendicular anisotropy was obtained by annealing the samples without an external magnetic field. The critical CoFeB thickness for perpendicular anisotropy was 1.8 nm; the anisotropy changes from out-of-plane to in-plane as the CoFeB thickness increases beyond this point. Perpendicular anisotropy was also enhanced when a Ta layer was capped on top of the MgO layer. The amorphous buffer provided better perpendicular anisotropy than previously reported Ta buffer, and it may be applied to perpendicular magnetization MRAM devices where good uniformity of tunnel junctions is required. - Highlights: • Perpendicular magnetic anisotropy (PMA) of buffer/CoFeB/MgO was investigated. • The PMA was enhanced by using an amorphous buffer. • The PMA of the CoFeB layer was maintained up to 1.8 nm. • Ta capping layer further improved the PMA by 40%.

  17. Influence of antiferromagnetic FeMn on magnetic properties of perpendicular magnetic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Feng Chun; Li Baohe; Teng Jiao; Jiang Yong [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Yu Guanghua [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)], E-mail: ghyu@mater.ustb.edu.cn

    2009-02-27

    We studied the influence of an anitferromagnetic FeMn layer on perpendicular magnetic anisotropy (PMA) and perpendicular coercivity (H{sub C}-perpendicular ) of the CoCr/Pt multilayers and found that both PMA and H{sub C}-perpendicular can be enhanced by the FeMn layer. We observed an obvious exchange coupling between FeMn and CoCr/Pt multilayers which enhances PMA and may increase the density of pinning sites that can pin the domain wall of ferromagnetic layers and lifts up energy barrier during the propagation of domain walls. This leads to the enhancement of H{sub C}-perpendicular . Moreover, X-ray diffraction results shows that the (111) texture of the FeMn layer enhances that of the CoCr/Pt multilayers, leading to the increase of PMA and H{sub C}-perpendicular as well. This result is of great significance on improving magnetic properties of perpendicular magnetic recording media by using an antiferromagnetic manganese alloy.

  18. Thermally robust perpendicular Co/Pd-based synthetic antiferromagnetic coupling enabled by a W capping or buffer layer.

    Science.gov (United States)

    Lee, Ja-Bin; An, Gwang-Guk; Yang, Seung-Mo; Park, Hae-Soo; Chung, Woo-Seong; Hong, Jin-Pyo

    2016-02-18

    Perpendicularly magnetized tunnel junctions (p-MTJs) that contain synthetic antiferromagnetic (SAF) frames show promise as reliable building blocks to meet the demands of perpendicular magnetic anisotropy (PMA)-based spintronic devices. In particular, Co/Pd multilayer-based SAFs have been widely employed due to their outstanding PMA features. However, the widespread utilization of Co/Pd multilayer SAFs coupled with an adjacent CoFeB reference layer (RL) is still a challenge due to the structural discontinuity or intermixing that occurs during high temperature annealing. Thus, we address the thermally robust characteristics of Co/Pd multilayer SAFs by controlling a W layer as a potential buffer or capping layer. The W-capped Co/Pd multilayer SAF, which acts as a pinning layer, exhibited a wide-range plateau with sharp spin-flip and near-zero remanence at the zero field. Structural analysis of the W-capped multilayer SAF exhibited single-crystal-like c-axis oriented crystalline features after annealing at 400 °C, thereby demonstrating the applicability of these frames. In addition, when the W layer serving as a buffer layer in the Co/Pd multilayer SAF was coupled with a conventional CoFeB RL, higher annealing stability up to 425 °C and prominent antiferromagnetic coupling behavior were obtained.

  19. Photoinhibition induced alterations in energy transfer process in phycobilisomes of PS II in the cyanobacterium, Spirulina platensis.

    Science.gov (United States)

    Kumar, Duvvuri Prasanna; Murthy, Sistla D S

    2007-09-30

    Exposure of algae or plants to irradiance from above the light saturation point of photosynthesis is known as high light stress. This high light stress induces various responses including photoinhibition of the photosynthetic apparatus. The degree of photoinhibition could be clearly determined by measuring the parameters such as absorption and fluorescence of chromoproteins. In cyanobacteria and red algae, most of the photosystem (PS) II associated light harvesting is performed by a membrane attached complex called the phycobilisome (PBS). The effects of high intensity light (1000-4000 micromol photons m(-2) s(-1)) on excitation energy transfer from PBSs to PS II in a cyanobacterium Spirulina platensis were studied by measuring room temperature PC fluorescence emission spectra. High light (3000 micromol photons m(-2) s(-1)) stress had a significant effect on PC fluorescence emission spectra. On the other hand, light stress induced an increase in the ratio of PC fluorescence intensity of PBS indicating that light stress inhibits excitation energy transfer from PBS to PS II. The high light treatment to 3000 micromol photons m(-2) s(-1) caused disappearance of 31.5 kDa linker polypeptide which is known to link PC discs together. In addition we observed the similar decrease in the other polypeptide contents. Our data concludes that the Spirulina cells upon light treatment causes alterations in the phycobiliproteins (PBPs) and affects the energy transfer process within the PBSs.

  20. Ultra-sensitive conductometric detection of heavy metals based on inhibition of alkaline phosphatase activity from Arthrospira platensis.

    Science.gov (United States)

    Tekaya, Nadèje; Saiapina, Olga; Ben Ouada, Hatem; Lagarde, Florence; Ben Ouada, Hafedh; Jaffrezic-Renault, Nicole

    2013-04-01

    This study is based on the conductometric measurement of alkaline phosphatase activity (APA) from the cyanobacterium, Arthrospira platensis, called Spirulina. Cyanobacterium cells were directly immobilized, by physical adsorption, on the ceramic part of gold interdigitated transducers. This activity was inhibited in the presence of heavy metals and a variation of the local conductivity was measured after addition of the substrate. The Michaelis-Menten constant (Km) was evaluated to be 0.75 mM through a calibration curve of the substrate, disodium 4-nitrophenylphosphate p-nitrophenyl phosphate (pNPP). Inhibition of APA was observed with cadmium and mercury with a detection limit of 10(-20) M. The half maximal inhibitory concentration (IC50) was determined at 10(-19) M for Cd(2+) and 10(-17) M for Hg(2+), and the binding affinity of heavy metal (Ki) was equal to the IC50. On the sensor surface, scanning electron microscopy (SEM) images revealed a remarkable evolution of the cyanobacterium's external surface that was attributable to the first defense mechanism against toxic heavy metals in trace. This effect was also confirmed through the important increase of response time τ(90%) recorded for APA response towards the substrate pNPP after cell exposure to metallic cations. Lifetime of the Spirulina-based biosensor was estimated to be more than 25 days.

  1. Purification of C-phycocyanin from Spirulina platensis in aqueous two-phase systems using an experimental design

    Directory of Open Access Journals (Sweden)

    Francine Silva Antelo

    2015-02-01

    Full Text Available C-phycocyanin from Spirulina platensis was purified in aqueous two-phase systems (ATPS of polyethylene glycol (PEG/potassium phosphate, varying the molar mass of the PEG. Results using a full factorial design showed that an increase in the concentration of salt and decrease in the concentration of PEG caused an increment in the purification factor for all the ATPS studied. Optimization of the conditions of the purification was studied using a central composite rotatable design for each molar mass of PEG. The ATPS composed of 7% (w/w PEG 1500 or 4% (w/w PEG 8000 (g/gmol and 23 or 22.5% (w/w of phosphate resulted a purification factor of 1.6-fold for C-phycocyanin, with total and 57% recovery, respectively. Process conditions were optimized for the purification factor for the system with PEG 1500. The ATPS with 4% (w/w PEG 4000 or 4% (w/w PEG 6000 and 21% (w/w phosphate resulted purification factors of 2.1 and 2.2-fold, recovering 100% and 73.5%, respectively of C-phycocyanin in the top phase.

  2. Effect of Spirulina Platensis Polysaccharide on Hematopoietic Recovery and Related Cytokines in Mice with Transplanted Tumor Treated by Chemotherapy

    Institute of Scientific and Technical Information of China (English)

    刘晓梅; 张洪泉

    2002-01-01

    Objective:To evaluate the effect of Spirulina platensis polysaccharide (SPP) on hematopoietic recovery and related cytokines in mice with transplanted tumor after chemotherapy. Methods:Mouse model of transplanted solid tumor was established and treated with chemotherapy. Peripheral blood cells, bone marrow nucleated cells, and colony forming unit-spleen (CFU-S) were counted; the content of DNA in bone marrow was inspected by ultraviolet spectrophotometer; serum content of cytokines, interleukin (IL)1, IL-3, granulocyte-macrophage colony stimulating factor (GM-CSF) and tumor necrosis factor-α (TNF-α) were determined by double antibody sandwich ELISA.Results:Cyclophosphamide (CTX) could induce evident myelosuppression, manifested as decrease of peripheral blood cells, bone marrow nucleated cell and DNA, and the CFU-S number. SPP could significantly ameliorate the myelosuppression induced by CTX without reducing anti-tumor effect of CTX. In addition, it could also increase the contents of IL-1, IL-3, GM-CSF, TNF-α in serum. Conclusion:SPP can probably accelerate the hematopoietic recovery in mice after chemotherapy through promoting endogenous secretion of cytokines.

  3. Value added by Spirulina platensis in two different diets on growth performance, gut microbiota, and meat quality of Japanese quails

    Directory of Open Access Journals (Sweden)

    Mohamed S. Yusuf

    2016-11-01

    Full Text Available Aim: The growth promoting effect of the blue-green filamentous alga Spirulina platensis (SP was observed on meat type Japanese quail with antibiotic growth promoter alternative and immune enhancing power. Materials and Methods: This study was conducted on 180 Japanese quail chicks for 4 weeks to find out the effect of diet type (vegetarian protein diet [VPD] and fish meal protein diet [FMPD]- Spirulina dose interaction (1 or 2 g/kg diet on growth perfor-mance, gut microbiota, and sensory meat quality of growing Japanese quails (1-5 weeks old. Results: Data revealed improvement (p<0.05 of weight gain, feed conversion ratio and European efficiency index due to 1, 2 g (SP/kg VPD, and 2 g (SP/kg FMPD, respectively. There was a significant decrease of ileum mean pH value by 1 g (SP/kg VPD. Concerning gut microbiota, there was a trend toward an increase in Lactobacilli count in both 1; 2 g (SP/kg VPD and 2 g (SP/kg FMPD. It was concluded that 1 or 2 g (SP/kg vegetarian diet may enhance parameters of performance without obvious effect on both meat quality and gut microbiota. Moreover, 1 and/or 2 g (SP may not be invited to share fish meal based diet for growing Japanese quails. Conclusion: Using of SP will support the profitable production of Japanese quails fed vegetable protein diet.

  4. Antioxidant and Angiostatic Effect of Spirulina platensis Suspension in Complete Freund’s Adjuvant-Induced Arthritis in Rats

    Science.gov (United States)

    Ali, Eman A. I.; Barakat, Bassant M.; Hassan, Ranya

    2015-01-01

    Background Currently, natural products have built a well-recognized role in the management of many degenerative diseases, mainly rheumatoid arthritis. Recent studies suggest that Spirulina, a unicellular blue-green alga, may have a variety of health benefits and curative properties and is also competent of acting as an anti-inflammatory, antioxidant and recently anti-angiogenic agent. In the present study, the antioxidant and the immunomodulatory effect of Spirulina platensis as well as its anti-angiogenic effect against complete Freund's adjuvant-induced arthritis (AIA) in rat model were tested. Results We found that the development of arthritis was concealed; moreover it successfully inhibited the development of macroscopic as well as microscopic and histopathological lesions in AIA rats when compared to control. Spirulina treated group showed a higher survival rate and moreover, it reduced the clinical score of RA in a dose dependent manner. Furthermore, Spirulina decreased serum levels of COX-2, TNF-α, IL-6, TBARS, VEGF and increased serum levels of GSH compared to the RA non-treated group. Conclusions The present study concluded that Spirulina is able to restrain the changes produced through adjuvant-induced arthritis. The suppressing effect of Spirulina could be attributed, at least in part, to anti-inflammatory, antioxidant and anti-angiogenic properties. PMID:25853428

  5. Purification and in vitro antioxidant activities of tellurium-containing phycobiliproteins from tellurium-enriched Spirulina platensis

    Science.gov (United States)

    Yang, Fang; Wong, Ka-Hing; Yang, Yufeng; Li, Xiaoling; Jiang, Jie; Zheng, Wenjie; Wu, Hualian; Chen, Tianfeng

    2014-01-01

    Tellurium-containing phycocyanin (Te-PC) and allophycocyanin (Te-APC), two organic tellurium (Te) species, were purified from tellurium-enriched Spirulina platensis by a fast protein liquid chromatographic method. It was found that the incorporation of Te into the peptides enhanced the antioxidant activities of both phycobiliproteins. With fractionation by ammonium sulfate precipitation and hydroxylapatite chromatography, Te-PC and Te-APC could be effectively separated with high purity, and Te concentrations were 611.1 and 625.3 μg g−1 protein in Te-PC and Te-APC, respectively. The subunits in the proteins were identified by using MALDI-TOF-TOF mass spectrometry. Te incorporation enhanced the antioxidant activities of both phycobiliproteins, as examined by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assay. Moreover, Te-PC and Te-APC showed dose-dependent protection on erythrocytes against the water-soluble free radical initiator 2,2′-azo(2-asmidinopropane)dihydrochloride-induced hemolysis. In the hepatoprotective model, apoptotic cell death and nuclear condensation induced by tert-butyl hydroperoxide in HepG2 cells was significantly attenuated by Te-PC and Te-APC. Taken together, these results suggest that Te-PC and Te-APC are promising Te-containing proteins with application potential for treatment of diseases related to oxidative stress. PMID:25336922

  6. Antagonistic effects of Spirulina platensis against sub-acute deltamethrin toxicity in mice: Biochemical and histopathological studies.

    Science.gov (United States)

    Abdel-Daim, Mohamed; El-Bialy, Badr E; Rahman, Haidy G Abdel; Radi, Abeer M; Hefny, Hany A; Hassan, Ahmed M

    2016-02-01

    Spirulina platensis (SP); a microalga with high antioxidant and anti-inflammatory activities, acts as a food supplement in human and as many animal species. Deltamethrin (DLM) is a synthetic pyrethroid with broad spectrum activities against acaricides and insects and widely used for veterinary and agricultural purposes. Exposure to DLM leads to hepatotoxic, nephrotoxic and neurotoxic side effects for human and many species, including birds and fish. The present study was undertaken to examine the potential hepatoprotective, nephroprotective, neuroprotective and antioxidant effects of SP against sub-acute DLM toxicity in male mice. DLM intoxicated animals revealed a significant increase in serum hepatic and renal injury biomarkers as well as TNF-α level and AChE activity. Moreover, liver, kidney and brain lipid peroxidation and oxidative stress markers were altered due to DLM toxicity. Spirulina normalized the altered serum levels of AST, ALT, APL, LDH, γ-GT, cholesterol, uric acid, urea, creatinine AChE and TNF-α. Furthermore, it reduced DLM-induced tissue lipid peroxidation, nitric oxide and oxidative stress in a dose-dependent manner. Collectively, that Spirulina supplementation could overcome DLM-induced hepatotoxicty, nephrotoxicity and neurotoxicity by abolishing oxidative tissue injuries.

  7. The effect of Spirulina platensis versus soybean on insulin resistance in HIV-infected patients: a randomized pilot study.

    Science.gov (United States)

    Marcel, Azabji-Kenfack; Ekali, Loni G; Eugene, Sobngwi; Arnold, Onana E; Sandrine, Edie D; von der Weid, Denis; Gbaguidi, Emmanuel; Ngogang, Jeanne; Mbanya, Jean C

    2011-07-01

    HIV-infected patients develop abnormalities of glucose metabolism due to the virus and antiretroviral drugs. Spirulina and soybean are nutritional supplements that are cheap, accessible in our community and affect glucose metabolism. We carried out a randomized study to assess the effect of Spirulina platensis versus soybean as a food supplement on HIV/HAART-associated insulin resistance (IR) in 33 insulin-resistant HIV-infected patients. The study lasted for two months at the National Obesity Centre of Cameroon. Insulin resistance was measured using the short insulin tolerance test. Physical activity and diet did not change over the study duration. On-treatment analysis was used to analyze data. The Mann-Whitney U test, the Students T test and the Chi square test were used as appropriate. Curve gradients were analyzed using ANCOVA. Seventeen subjects were randomized to spirulina and 16 to soybean. Each received 19 g of supplement daily. The follow up rate was 65% vs. 100% for spirulina and soybean groups, respectively, and both groups were comparable at baseline. After eight weeks, insulin sensitivity (IS) increased by 224.7% vs. 60% in the spirulina and soybean groups respectively (p spirulina versus soybean, respectively, improved their IS (p = 0.049) with a 1.45 (1.05-2.02) chance of improving insulin sensitivity on spirulina. This pilot study suggests that insulin sensitivity in HIV patients improves more when spirulina rather than soybean is used as a nutritional supplement. ClinicalTrials.gov identifier NCT01141777.

  8. Anti-inflammatory and anti-pyretic properties of Spirulina platensis and Spirulina lonar: a comparative study.

    Science.gov (United States)

    Somchit, Muhammad Nazrul; Mohamed, Nor Azura; Ahmad, Zuraini; Zakaria, Zainul Amiruddin; Shamsuddin, Lokman; Omar-Fauzee, Mohd Sofian; Kadir, Arifah Abdul

    2014-09-01

    Spirulina spp. is a blue-green algae belongs to the family of Oscillatoriaceae, which having diverse biological activity. The aim of this current study was to evaluate and compare the anti-pyretic and anti-inflammatory activity of Spirulina platensis/SP and Spirulina lonar/SL extracts. In the anti-pyretic study, the ability to reduce the rectal temperature of rats induced pyrexia with 2g/kg Brewer's Yeast (BY) was performed. Rats were dosed either 2 or 4 mg/kg SP or SL. Rectal temperature was taken every hour for 8 hours. Results shown that there were significant dose-dependent (p<0.05) reduction of both treatments. However, SP treatment revealed faster reduction in rectal temperature. For anti-inflammatory activity, the reduction in the volume of paw edema induced by Prostaglandin E2 (100 IU/rat intraplantar) was measured. Rats were dosed orally with 2 or 4 mg/kg SP or SL. The paw edema was measured every 30 minutes for 4 hours using plethysmometer. Results had shown a significant dose dependent reduction in diameter of paw edema (p<0.05). The finding suggests that SP and SL extracts have anti-pyretic and anti-inflammatory properties. However, SP was found to be more effective than SL as anti-pyretic and anti-inflammatory agent.

  9. Antioxidant and angiostatic effect of Spirulina platensis suspension in complete Freund's adjuvant-induced arthritis in rats.

    Science.gov (United States)

    Ali, Eman A I; Barakat, Bassant M; Hassan, Ranya

    2015-01-01

    Currently, natural products have built a well-recognized role in the management of many degenerative diseases, mainly rheumatoid arthritis. Recent studies suggest that Spirulina, a unicellular blue-green alga, may have a variety of health benefits and curative properties and is also competent of acting as an anti-inflammatory, antioxidant and recently anti-angiogenic agent. In the present study, the antioxidant and the immunomodulatory effect of Spirulina platensis as well as its anti-angiogenic effect against complete Freund's adjuvant-induced arthritis (AIA) in rat model were tested. We found that the development of arthritis was concealed; moreover it successfully inhibited the development of macroscopic as well as microscopic and histopathological lesions in AIA rats when compared to control. Spirulina treated group showed a higher survival rate and moreover, it reduced the clinical score of RA in a dose dependent manner. Furthermore, Spirulina decreased serum levels of COX-2, TNF-α, IL-6, TBARS, VEGF and increased serum levels of GSH compared to the RA non-treated group. The present study concluded that Spirulina is able to restrain the changes produced through adjuvant-induced arthritis. The suppressing effect of Spirulina could be attributed, at least in part, to anti-inflammatory, antioxidant and anti-angiogenic properties.

  10. Purification, crystallization and preliminary X-ray diffraction studies of C-phycocyanin and allophycocyanin from Spirulina platensis.

    Science.gov (United States)

    Moreno, A; Bermejo, R; Talavera, E; Alvarez-Pez, J M; Sanz-Aparicio, J; Romero-Garrido, A

    1997-05-01

    C-phycocyanin and allophycocyanin from the green alga Spirulina platensis were isolated and crystallized by gel-acupuncture techniques. A novel two-step chromatographic procedure was used for purification. Blue hexagonal crystals were obtained by diffusing magnesium chloride into the protein solution for a week, followed by diffusion of PEG 6000 in order to complete the reduction of the solubility of the protein in the capillary tube used as a growth cell. In the case of allophycocyanin, crystals with a size of 0.4 x 0.3 x 0.3 mm were characterized by X-ray diffraction. They belong to space group P6(3)22 with unit-cell parameters a = b = 102.04, c = 131.22 A. The crystals of C-phycocyanin belong to either space group P6 or P6(3) with unit-cell constants a = b = 182.38, c = 60.87 A, alpha = beta = 90, gamma = 120 degrees. The crystals diffract beyond 2.4 and 2.5 A resolution, respectively, using a rotating anode as an X-ray source.

  11. Antioxidant and angiostatic effect of Spirulina platensis suspension in complete Freund's adjuvant-induced arthritis in rats.

    Directory of Open Access Journals (Sweden)

    Eman A I Ali

    Full Text Available Currently, natural products have built a well-recognized role in the management of many degenerative diseases, mainly rheumatoid arthritis. Recent studies suggest that Spirulina, a unicellular blue-green alga, may have a variety of health benefits and curative properties and is also competent of acting as an anti-inflammatory, antioxidant and recently anti-angiogenic agent. In the present study, the antioxidant and the immunomodulatory effect of Spirulina platensis as well as its anti-angiogenic effect against complete Freund's adjuvant-induced arthritis (AIA in rat model were tested.We found that the development of arthritis was concealed; moreover it successfully inhibited the development of macroscopic as well as microscopic and histopathological lesions in AIA rats when compared to control. Spirulina treated group showed a higher survival rate and moreover, it reduced the clinical score of RA in a dose dependent manner. Furthermore, Spirulina decreased serum levels of COX-2, TNF-α, IL-6, TBARS, VEGF and increased serum levels of GSH compared to the RA non-treated group.The present study concluded that Spirulina is able to restrain the changes produced through adjuvant-induced arthritis. The suppressing effect of Spirulina could be attributed, at least in part, to anti-inflammatory, antioxidant and anti-angiogenic properties.

  12. Inhibition of cultured bovine aortic endothelial cell proliferation by sodium spirulan, a new sulfated polysaccharide isolated from Spirulina platensis.

    Science.gov (United States)

    Kaji, Toshiyuki; Fujiwara, Yasuyuki; Hamada, Chieko; Yamamoto, Chika; Shimada, Satomi; Lee, Jung-Bum; Hayashi, Toshimitsu

    2002-06-01

    Sodium spirulan (Na-SP) is a sulfated polysaccharide isolated from the blue-green alga Spirulina platensis, which consists of two types of disaccharide repeating units, O-hexuronosyl-rhamnose (aldobiuronic acid) and O-rhamnosyl-3-O-methylrhamnose (acofriose) with sulfate groups, other minor saccharides and sodium ion. Vascular endothelial cells are present on the inner surface of blood vessels in a monolayer and have anticoagulant properties. To address the question whether Na-SP influences the maintenance of endothelial cell monolayers, we investigated the proliferation of cultured bovine aortic endothelial cells treated with Na-SP. It was found that Na-SP has an inhibitory activity on endothelial cell proliferation accompanied with suppression of whole protein synthesis but without non-specific cell damage. The inhibitory activity of Na-SP was the strongest when compared to that of heparan sulfate, heparin, dextran sulfate, dermatan sulfate, chondroitin sulfate A/C and hyaluronan. Furthermore, it was shown that the inhibitory activity of Na-SP disappeared by either desulfation or depolymerization. The present data suggest that Na-SP is a unique sulfated polysaccharide that strongly inhibits vascular endothelial cell proliferation, and the inhibitory activity requires polymerization of sulfated O-rhamnosyl-acofriose repeating units.

  13. Impact of bubble size on growth and CO2 uptake of Arthrospira (Spirulina) platensis KMMCC CY-007.

    Science.gov (United States)

    Kim, Kisok; Choi, Jaeho; Ji, Yosep; Park, Soyoung; Do, Hyungki; Hwang, Cherwon; Lee, Bongju; Holzapfel, Wilhelm

    2014-10-01

    Optimisation of cyanobacterial cell productivity should consider the key factors light cycle and carbon source. We studied the influence of CO2 bubble size on carbon uptake and fixation, on basis of mRNA expression levels in Arthrospira platensis KMMCC CY-007 at 30°C (light intensity: 40μmolm(-2)s(-1); 1% CO2). Growth rate, carbon fixation and lipid accumulation were examined over 7days under fine bubble (FB) (100μm Ø) bulk bubble (BB) (5000μm Ø) and non-CO2 (NB) aeration. The low affinity CO2 uptake mRNA (NDH-I4 complex) was stronger expressed than the high affinity NDH-I3 complex (bicA and sbtA) under 1% CO2 and FB conditions, with no expression of bicA1 and sbtA1 after 4days. The high affinity CO2 uptake mRNA levels corresponded to biomass, carbon content and lipid accumulation, and increase in NDH-I3 complex (9.72-fold), bicA (5.69-fold), and sbtA (10.61-fold), compared to NB, or BB conditions.

  14. Perpendicular diffusion of a dilute beam of charged dust particles in a strongly coupled dusty plasma

    Science.gov (United States)

    Liu, Bin; Goree, J.

    2014-06-01

    The diffusion of projectiles drifting through a target of strongly coupled dusty plasma is investigated in a simulation. A projectile's drift is driven by a constant force F. We characterize the random walk of the projectiles in the direction perpendicular to their drift. The perpendicular diffusion coefficient Dp⊥ is obtained from the simulation data. The force dependence of Dp⊥ is found to be a power law in a high force regime, but a constant at low forces. A mean kinetic energy Wp for perpendicular motion is also obtained. The diffusion coefficient is found to increase with Wp with a linear trend at higher energies, but an exponential trend at lower energies.

  15. Influence of Extractive Solvents on Lipid and Fatty Acids Content of Edible Freshwater Algal and Seaweed Products, the Green Microalga Chlorella kessleri and the Cyanobacterium Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Jarmila Vavra Ambrozova

    2014-02-01

    Full Text Available Total lipid contents of green (Chlorella pyrenoidosa, C, red (Porphyra tenera, N; Palmaria palmata, D, and brown (Laminaria japonica, K; Eisenia bicyclis, A; Undaria pinnatifida, W, WI; Hizikia fusiformis, H commercial edible algal and cyanobacterial (Spirulina platensis, S products, and autotrophically cultivated samples of the green microalga Chlorella kessleri (CK and the cyanobacterium Spirulina platensis (SP were determined using a solvent mixture of methanol/chloroform/water (1:2:1, v/v/v, solvent I and n-hexane (solvent II. Total lipid contents ranged from 0.64% (II to 18.02% (I by dry weight and the highest total lipid content was observed in the autotrophically cultivated cyanobacterium Spirulina platensis. Solvent mixture I was found to be more effective than solvent II. Fatty acids were determined by gas chromatography of their methyl esters (% of total FAMEs. Generally, the predominant fatty acids (all results for extractions with solvent mixture I were saturated palmitic acid (C16:0; 24.64%–65.49%, monounsaturated oleic acid (C18:1(n-9; 2.79%–26.45%, polyunsaturated linoleic acid (C18:2(n-6; 0.71%–36.38%, α-linolenic acid (C18:3(n-3; 0.00%–21.29%, γ-linolenic acid (C18:3(n-6; 1.94%–17.36%, and arachidonic acid (C20:4(n-6; 0.00%–15.37%. The highest content of ω-3 fatty acids (21.29% was determined in Chlorella pyrenoidosa using solvent I, while conversely, the highest content of ω-6 fatty acids (41.42% was observed in Chlorella kessleri using the same solvent.

  16. Approach to fabricating Co nanowire arrays with perpendicular anisotropy: Application of a magnetic field during deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Shihui; Li, Chao; Ma, Xiao; Li, Wei; Xi, Li; Li, C. X.

    2001-07-01

    Cobalt (Co) nanowire arrays were electrodeposited into the pores of polycarbonate membranes. A magnetic field parallel or perpendicular to the membrane plane was applied during deposition to control the wire growth. X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer were employed to investigate the structure as well as the magnetic properties of the nanowire arrays. The results show that the magnetic field applied during deposition strongly influences the growth of Co nanowires, inducing variations in their crystalline structure and magnetic properties. The sample deposited with the field perpendicular to the membrane plane exhibits a perpendicular magnetic anisotropy with greatly enhanced coercivity and squareness as a result of the preferred growth of Co grains with the c axis perpendicular to the film plane. In contrast, the deposition in a parallel magnetic field forces Co grains to grow with the c axis parallel to the film plane, resulting in in-plane anisotropy. {copyright} 2001 American Institute of Physics.

  17. Selective-resputtering-induced perpendicular magnetic anisotropy in amorphous TbFe films.

    Science.gov (United States)

    Harris, V G; Pokhil, T

    2001-08-06

    Perpendicular magnetic anisotropy energy in rf magnetron sputtered amorphous TbFe films is measured to increase exponentially with pair-order anisotropy induced by the selective resputtering of surface adatoms during film growth.

  18. Perpendicular orientation of cylindrical domains upon solvent annealing thin films of polystyrene-b-polylactide

    Energy Technology Data Exchange (ETDEWEB)

    Vayer, Marylene [Centre de Recherche sur la Matiere Divisee, 1b rue de la Ferollerie, 45071 Orleans (France); Hillmyer, Marc A. [University of Minnesota, Department of Chemistry, Minneapolis, MN 55455-0431 (United States); Dirany, Mohammed; Thevenin, Guillaume; Erre, Rene [Centre de Recherche sur la Matiere Divisee, 1b rue de la Ferollerie, 45071 Orleans (France); Sinturel, Christophe, E-mail: christophe.sinturel@univ-orleans.f [Centre de Recherche sur la Matiere Divisee, 1b rue de la Ferollerie, 45071 Orleans (France)

    2010-05-03

    Polystyrene-b-polylactide (PS-PLA) was employed as a precursor to nanoporous thin films containing perpendicular cylindrical channels. Cylinder-forming PS-PLA was spin coated onto Si substrate and solvent annealed using acetone, chlorobenzene and tetrahydrofuran (THF) for different durations. By atomic force microscopy, three types of final morphology were observed at the free surface of the films (PLA surface layer, perpendicular cylinders and parallel cylinders) depending on the type of solvent and annealing time. Well-organized perpendicular domains were obtained by annealing in THF. From this oriented PS-PLA annealed thin films, a mild hydrolysis led to a highly ordered array of perpendicularly-oriented cylindrical nanopores arranged on a hexagonal lattice, rendering the resulting nanoporous mask useful for nanopattern transfer processes. The weak resistance of the film/substrate interface during PLA etching was overcome by UV light exposure prior hydrolysis.

  19. Spin-orbit interaction tuning of perpendicular magnetic anisotropy in L1{sub 0} FePdPt films

    Energy Technology Data Exchange (ETDEWEB)

    Ma, X.; Lüpke, G., E-mail: gyguo@phys.ntu.edu.tw, E-mail: hbzhao@fudan.edu.cn, E-mail: gxluep@wm.edu [Department of Applied Science, College of William and Mary, 251 Jamestown Road, Williamsburg, Virginia 23187 (United States); He, P.; Ma, L.; Zhou, S. M. [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Guo, G. Y., E-mail: gyguo@phys.ntu.edu.tw, E-mail: hbzhao@fudan.edu.cn, E-mail: gxluep@wm.edu [Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Zhao, H. B., E-mail: gyguo@phys.ntu.edu.tw, E-mail: hbzhao@fudan.edu.cn, E-mail: gxluep@wm.edu [Department of Optical Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433 (China)

    2014-05-12

    The dependence of perpendicular magnetic anisotropy K{sub u} on spin-orbit coupling strength ξ is investigated in L1{sub 0} ordered FePd{sub 1−x}Pt{sub x} films by time-resolved magneto-optical Kerr effect measurements and ab initio density functional calculations. Continuous tuning of K{sub u} over a wide range of magnitude is realized by changing the Pt/Pd concentration ratio, which strongly modifies ξ but keeps other leading parameters affecting K{sub u} nearly unchanged. Ab initio calculations predict a nearly quadratic dependence of K{sub u} on ξ, consistent with experimental data. K{sub u} increases with increasing chemical order and decreasing thermal spin fluctuations, which becomes more significant for samples with higher Pt concentration. The results demonstrate an effective method to tune K{sub u} utilizing its sensitivity on ξ, which will help fabricate magnetic systems with desirable magnetic anisotropy.

  20. Electrodeposition of Fe/Au(1 1 1) ultrathin layers with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Guendel, A. [Laboratoire de Physique de la Matiere Condensee (CNRS UMR 7643), Ecole Polytechnique, F-91128 Palaiseau (France) and Laboratorio de Magnetismo, Instituto de Fisica-UFRGS 91501-970 Porto Alegre RS (Brazil)]. E-mail: gundel@smail.ufsm.br; Devolder, T. [Institut d' Electronique Fondamentale (CNRS UMR 8622) Bat. 220, Universite Paris-Sud, F-91405 Orsay (France); Chappert, C. [Institut d' Electronique Fondamentale (CNRS UMR 8622) Bat. 220, Universite Paris-Sud, F-91405 Orsay (France); Schmidt, J.E. [Laboratorio de Magnetismo, Instituto de Fisica--UFRGS 91501-970 Porto Alegre RS (Brazil); Cortes, R. [Laboratoire de Physique de la Matiere Condensee (CNRS UMR 7643), Ecole Polytechnique, F-91128 Palaiseau (France); Allongue, P. [Laboratoire de Physique de la Matiere Condensee (CNRS UMR 7643), Ecole Polytechnique, F-91128 Palaiseau (France)

    2004-12-31

    The magnetic state of electrodeposited iron on Au(1 1 1) substrates is investigated during the electrodeposition process by means of in situ alternating gradient force magnetometer (AGFM) and in situ perpendicular magneto-optic Kerr effect measurements (PMOKE). A perpendicular magnetic anisotropy (PMA) is observed for a thickness below 2 monolayers (ML). In situ STM observations of the initial stages of iron growth and ex situ EXAFS are used to correlate the structure of films to their magnetic properties.

  1. Energy values and chemical composition of spirulina (Spirulina platensis evaluated with broilers Valores energéticos e composição química da espirulina (Spirulina platensis avaliada com frangos de corte

    Directory of Open Access Journals (Sweden)

    Renata Ribeiro Alvarenga

    2011-05-01

    Full Text Available The objective of this study was to determine the chemical and energy composition of spirulina (Spirulina platensis, the nutrient metabolizability coefficients, and the values of apparent metabolizable energy (AME and the apparent metabolizable energy corrected for nitrogen balance (AMEn in broilers. A digestibility trial was carried out by using total excreta collection method, with 90 Cobb 500 lineage chicks, with initial weight of 256 ± 5 g at 11 days of age. Birds were allotted in metabolic cages for 10 days, distributed in a completely randomized design, with three treatments and six repetitions with five birds each. Diets consisted on a reference-ration based on corn and soybean meal and two test diets, one containing spirulina (30% and the other one with soybean meal (30%. Spiruline was superior to soybean meal for contents of dry matter (DM, gross energy (9.60%, crude protein (26.56%, ether extract (54.45%, mineral matter (42.77%, calcium (100% and total phosphorus (130.77% and also for most amino acids, except lysine, glutamate, histidine and proline. Nevertheless, spiruline presented lower values of gross fiber (83.95%, acid detergent fiber (85.12% and neutral detergent fiber (6.15. The AME and AMEn values (kcal/kg of DM were, respectively, 2,906 and 2,502 for the spirulina and 2,646 and 2,340 for the soybean meal and AMEn of spirulina was 6.92% higher than soybean meal.Objetivou-se determinar a composição química e energética da espirulina (Spirulina platensis, os coeficientes de metabolizabilidade dos nutrientes e os valores de energia metabolizável aparente (EMA e aparente corrigida pelo balanço de nitrogênio (EMAn em frangos de corte. Realizou-se um ensaio de digestibilidade utilizando-se a metodologia de coleta total de excretas com 90 pintos machos da linhagem Cobb 500, com peso inicial de 256 ± 5 g aos 11 dias de idade. As aves foram alojadas em gaiolas de metabolismo durante dez dias, distribuídas em delineamento

  2. 钝顶螺旋藻(Spirulina platensis)对生活污水的生物净化与修复%Purification of domestic wastewater by Spirulina platensis

    Institute of Scientific and Technical Information of China (English)

    黄昆; 黄峙; 郑文杰

    2010-01-01

    探讨了钝顶螺旋藻(Spirulina platensis,SP)对生活污水的生物修复与净化作用.用厨房污水(KW)接种SP后摇瓶光照培养,观察藻细胞在KW中的生长状态,分析其中β-胡萝卜素和C-藻蓝蛋白的含量,并比较接种前和培养10 d后KW中BOD、COD、NH_3-N、NO~-_3-N和PO~3-P质量浓度的变化.结果发现,SP可在KW原液(KW100)和80 %(体积分数)KW(KW80)中维持较好生长,并且藻细胞中C-藻蓝蛋白含量明显增加(P<0.05).培养10 d后,KW100中BOD、COD、NH_3-N、NO~-_3-N和PO_4~(3-)-P的去除率分别为77.6 %、75.2 %、97.8 %、98.2 %和64.5 %,对KW100中Zn、Se等元素能够有效富集,对一些重金属污染物的去除率也大于50 %.研究结果表明,螺旋藻培养对生活污水有较好的生物净化作用.

  3. COLONY FORMATION AND SELENIUM-ENRICHED STABILITY OF SPIRULINA PLATENSIS UNDER SELENIUM STRESS%硒胁迫螺旋藻(Spirulina platensis)集落形成及富硒稳定性

    Institute of Scientific and Technical Information of China (English)

    黄峙; 郑文杰; 杨芳; 郭宝江

    2005-01-01

    探讨在琼脂糖半固体培养基中硒胁迫螺旋藻(Spirulina platensis,SP)集落形成及其富硒稳定性.培养基中添加亚硒酸钠,硒含量分别为2.5 mmol L-1、5 mmol L-1和10 mmol L-1,培养并观察螺旋藻集落形成,挑取藻集落进行富硒培养,多次转种后,测定生长率、硒含量,筛选稳定的富硒螺旋藻.从含硒5 mmol L-1的培养皿中挑选12个典型藻丝集落接种培养,发现其中6个生长率达到对照的80%,有两个藻集落(编号为SP0803和SP0809)硒含量较高,干藻硒含量分别为p(Se)=924μg/g和p(Se)=831μg/g,连续3次转种培养,藻体含硒量保持稳定.以上结果表明,利用琼脂糖半固体培养基进行微藻集落培养是可行的,并成功筛选到富硒螺旋藻.图3表2参12

  4. Protective effects of a polysaccharide fromSpirulina platensis on dopaminergic neurons in an MPTP-induced Parkinson’s disease model in C57BL/6J mice

    Institute of Scientific and Technical Information of China (English)

    Fang Zhang; Jian Lu; Ji-guo Zhang; Jun-xia Xie

    2015-01-01

    The present study aimed to determine whether a polysaccharide obtained fromSpirulina platensis shows protective effects on dopaminergic neurons. A Parkinson’s disease model was established through the intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyr-idine (MPTP) in C57BL/6J mice. Prior to the MPTP injection, some mice were pretreated with intraperitoneal injections of a polysaccharide derived fromSpirulina platensis once daily for 10 days. The results showed that the immunoreactive staining and mRNA expression of the dopa-mine transporter and tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis, in the substantia nigra, were signiifcantly increased in mice pretreated with 800 mg/kg of the poly-saccharide compared with those in MPTP-treated mice. The activities of superoxide dismutase and glutathione peroxidase in the serum and midbrain were also increased signiifcantly in mice injected with MPTP after pretreatment with the polysaccharide fromSpirulina platensis. By con-trast, the activity of monoamine oxidase B in serum and midbrain maintained unchanged. These experimental ifndings indicate that the polysaccharide obtained fromSpirulina platensis plays a protective role against the MPTP-induced loss of dopaminergic neurons in C57BL/6J mice, and that the antioxidative properties of this polysaccharide likely underlie its neuroprotective effect.

  5. 鸡粪、牛粪浸出液培养螺旋藻效果的比较研究%The comparative study on the culture of Spirulina platensis in the leach liquor of chicken manure and cow dung

    Institute of Scientific and Technical Information of China (English)

    周贤君; 潘文敏

    2013-01-01

    By using the farming culture method indoor, the Spirulina platensis was cultured in the leach liquor of chicken manure and cow dung to compare their cultivation effect. The result showed that: The Spirulina platensis could grow in both of chicken manure and cow dung lixivi-um. The growth rate of Spirulina platensis in the chicken manure lixivium was faster than that in the cow dung, and the production of Spirulina platensis was higher than that in the cow dung.%  研究通过室内养殖培养法,利用鸡粪、牛粪浸出液对螺旋藻进行培养,并对其培养效果进行比较。试验结果表明:螺旋藻在鸡粪和牛粪浸出液中均能生长。在鸡粪浸出液中培养的延缓期较牛粪中长,但藻细胞生长更快,藻细胞密度达到的最大值高于牛粪浸出液。

  6. The Effect of Spirulina platensis versus Soybean on Insulin Resistance in HIV-Infected Patients: A Randomized Pilot Study

    Directory of Open Access Journals (Sweden)

    Jeanne Ngogang

    2011-07-01

    Full Text Available HIV-infected patients develop abnormalities of glucose metabolism due to the virus and antiretroviral drugs. Spirulina and soybean are nutritional supplements that are cheap, accessible in our community and affect glucose metabolism. We carried out a randomized study to assess the effect of Spirulina platensis versus soybean as a food supplement on HIV/HAART-associated insulin resistance (IR in 33 insulin-resistant HIV-infected patients. The study lasted for two months at the National Obesity Centre of Cameroon. Insulin resistance was measured using the short insulin tolerance test. Physical activity and diet did not change over the study duration. On-treatment analysis was used to analyze data. The Mann-Whitney U test, the Students T test and the Chi square test were used as appropriate. Curve gradients were analyzed using ANCOVA. Seventeen subjects were randomized to spirulina and 16 to soybean. Each received 19 g of supplement daily. The follow up rate was 65% vs. 100% for spirulina and soybean groups, respectively, and both groups were comparable at baseline. After eight weeks, insulin sensitivity (IS increased by 224.7% vs. 60% in the spirulina and soybean groups respectively (p < 0.001. One hundred per cent vs. 69% of subjects on spirulina versus soybean, respectively, improved their IS (p = 0.049 with a 1.45 (1.05–2.02 chance of improving insulin sensitivity on spirulina. This pilot study suggests that insulin sensitivity in HIV patients improves more when spirulina rather than soybean is used as a nutritional supplement. Trial registration: ClinicalTrials.gov identifier NCT01141777.

  7. Efficacy of Spirulina platensis in improvement of the reproductive performance and easing teratogenicity in hyperglycemic albino mice

    Directory of Open Access Journals (Sweden)

    Pranay Punj Pankaj

    2015-01-01

    Full Text Available Objectives: The present study evaluates the therapeutic efficacy of cell suspension of Spirulina platensis (SP on estrous cycle, fetal development and embryopathy in alloxan (AXN induced hyperglycemic mice. Materials and Methods: Diabetes was induced by intra-peritoneal administration of AXN. Mice with blood glucose level above 200 mg/dl were divided into Group I (control, Group II (diabetic control, Group III (diabetic control mice fed with SP, and Group IV (control mice fed with SP. Litter counts, estrous cycles, percent survival of litter, and gestation length were recorded. Results: In hyperglycemic mice, a significant (P < 0.05 increase in duration of diestrus (14.48%, estrus (84.21%, and metestrus (164.15% with concomitant decrease in proestrus phase by 26.13% was recorded when compared with control. Reduction in litter count and survival of litter was 68.67% and 88.38%, respectively, whereas gestation length increased to 14.51% day in diabetic mice, but recovery in these parameters was observed (P < 0.05 when subjected to SP treatment. SP resulted in increased fertility rate from 77.5% to 82.5% and dropped off resorption of the fetus to 33.73% while the survival rate of offspring of diabetic mice went up to 88.89% from 83.61%. Conclusions: These findings suggest that SP is effective in improving the reproductive performance and easing teratogenic effects in diabetic mice and hence warrants further detailed dose-dependent studies to understand its mechanism of action.

  8. The Effect of Spirulina platensis versus Soybean on Insulin Resistance in HIV-Infected Patients: A Randomized Pilot Study

    Science.gov (United States)

    Marcel, Azabji-Kenfack; Ekali, Loni G.; Eugene, Sobngwi; Arnold, Onana E.; Sandrine, Edie D.; von der Weid, Denis; Gbaguidi, Emmanuel; Ngogang, Jeanne; Mbanya, Jean C.

    2011-01-01

    HIV-infected patients develop abnormalities of glucose metabolism due to the virus and antiretroviral drugs. Spirulina and soybean are nutritional supplements that are cheap, accessible in our community and affect glucose metabolism. We carried out a randomized study to assess the effect of Spirulina platensis versus soybean as a food supplement on HIV/HAART-associated insulin resistance (IR) in 33 insulin-resistant HIV-infected patients. The study lasted for two months at the National Obesity Centre of Cameroon. Insulin resistance was measured using the short insulin tolerance test. Physical activity and diet did not change over the study duration. On-treatment analysis was used to analyze data. The Mann-Whitney U test, the Students T test and the Chi square test were used as appropriate. Curve gradients were analyzed using ANCOVA. Seventeen subjects were randomized to spirulina and 16 to soybean. Each received 19 g of supplement daily. The follow up rate was 65% vs. 100% for spirulina and soybean groups, respectively, and both groups were comparable at baseline. After eight weeks, insulin sensitivity (IS) increased by 224.7% vs. 60% in the spirulina and soybean groups respectively (p < 0.001). One hundred per cent vs. 69% of subjects on spirulina versus soybean, respectively, improved their IS (p = 0.049) with a 1.45 (1.05–2.02) chance of improving insulin sensitivity on spirulina. This pilot study suggests that insulin sensitivity in HIV patients improves more when spirulina rather than soybean is used as a nutritional supplement. Trial registration: ClinicalTrials.gov identifier NCT01141777. PMID:22254118

  9. Efficacy of Spirulina platensis in improvement of the reproductive performance and easing teratogenicity in hyperglycemic albino mice

    Science.gov (United States)

    Pankaj, Pranay Punj

    2015-01-01

    Objectives: The present study evaluates the therapeutic efficacy of cell suspension of Spirulina platensis (SP) on estrous cycle, fetal development and embryopathy in alloxan (AXN) induced hyperglycemic mice. Materials and Methods: Diabetes was induced by intra-peritoneal administration of AXN. Mice with blood glucose level above 200 mg/dl were divided into Group I (control), Group II (diabetic control), Group III (diabetic control mice fed with SP), and Group IV (control mice fed with SP). Litter counts, estrous cycles, percent survival of litter, and gestation length were recorded. Results: In hyperglycemic mice, a significant (P < 0.05) increase in duration of diestrus (14.48%), estrus (84.21%), and metestrus (164.15%) with concomitant decrease in proestrus phase by 26.13% was recorded when compared with control. Reduction in litter count and survival of litter was 68.67% and 88.38%, respectively, whereas gestation length increased to 14.51% day in diabetic mice, but recovery in these parameters was observed (P < 0.05) when subjected to SP treatment. SP resulted in increased fertility rate from 77.5% to 82.5% and dropped off resorption of the fetus to 33.73% while the survival rate of offspring of diabetic mice went up to 88.89% from 83.61%. Conclusions: These findings suggest that SP is effective in improving the reproductive performance and easing teratogenic effects in diabetic mice and hence warrants further detailed dose-dependent studies to understand its mechanism of action. PMID:26285837

  10. Hepatoprotective efficacy of Spirulina platensis against lead-induced oxidative stress and genotoxicity in catfish; Clarias gariepinus.

    Science.gov (United States)

    Sayed, Alaa El-Din H; El-Sayed, Yasser S; El-Far, Ali H

    2017-09-01

    Lead (Pb) is a toxic environmental pollutant that induces a broad range of biochemical and physiological hazards in living organisms. We investigated the possible hepatoprotective effects of Spirulina platensis (SP) in counteracting the Pb-induced oxidative damage. Ninety-six adult African catfish were allocated into four equal groups. The 1st group (control) fed basal diet while the 2nd group (Pb-treated) fed on basal diet and exposed to 1mg Pb(NO3)2/L. The 3rd and 4th groups fed SP-supplemented basal diets at levels of 0.25% and 0.5%, respectively and exposed to Pb. Serum samples were used to analyze hepatic function biomarkers, electrolytes, and oxidant and antioxidant status. Lipid peroxidation and DNA fragmentation were determined in the liver tissues. Pb exposure induced hepatic dysfunction, electrolytes (Na(+), K(+), Ca(+2), and Cl(-)) imbalance, as well a significant decrease in GSH content, and LDH, AChE, SOD, CAT and GST enzymes activity. SP supplementation reverted these biochemical and genetic alterations close to control levels. This amelioration was higher with 0.5% SP and at the 4th week of exposure, showing concentration- and time-dependency. Thus, the current study suggests that SP could protect the catfish liver against lead-induced injury by scavenging ROS, sustaining the antioxidant status and diminishing DNA oxidative damage. The dietary inclusion of SP can be used as a promising protective agent to counteract oxidative stress-mediated diseases and toxicities. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Calcium spirulan derived from Spirulina platensis inhibits herpes simplex virus 1 attachment to human keratinocytes and protects against herpes labialis.

    Science.gov (United States)

    Mader, Julia; Gallo, Antonio; Schommartz, Tim; Handke, Wiebke; Nagel, Claus-Henning; Günther, Patrick; Brune, Wolfram; Reich, Kristian

    2016-01-01

    Chronic infections with herpes simplex virus (HSV) type 1 are highly prevalent in populations worldwide and cause recurrent oral lesions in up to 40% of infected subjects. We investigated the antiviral activity of a defined Spirulina platensis microalga extract and of purified calcium spirulan (Ca-SP), a sulfated polysaccharide contained therein. The inhibitory effects of HSV-1 were assessed by using a plaque reduction assay and quantitative PCR in a susceptible mammalian epithelial cell line and confirmed in human keratinocytes. Time-of-addition and attachment experiments and fluorescence detection of the HSV-1 tegument protein VP16 were used to analyze the mechanism of HSV-1 inhibition. Effects of Ca-SP on Kaposi sarcoma-associated herpesvirus/human herpes virus 8 replication and uptake of the ORF45 tegument protein were tested in human retinal pigment epithelial cells. In an observational trial the prophylactic effects of topically applied Ca-SP were compared with those of systemic and topical nucleoside analogues in 198 volunteers with recurrent herpes labialis receiving permanent lip makeup. Ca-SP inhibited HSV-1 infection in vitro with a potency at least comparable to that of acyclovir by blocking viral attachment and penetration into host cells. Ca-SP also inhibited entry of Kaposi sarcoma-associated herpesvirus/human herpes virus 8. In the clinical model of herpes exacerbation, the prophylactic effect of a Ca-SP and microalgae extract containing cream was superior to that of acyclovir cream. These data indicate a potential clinical use of Ca-SP containing Spirulina species extract for the prophylactic treatment of herpes labialis and suggest possible activity of Ca-SP against infections caused by other herpesviruses. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  12. Purification and characterization of cytochrome f-556.5 from the blue-green alga Spirulina platensis.

    Science.gov (United States)

    Böhme, H; Pelzer, B; Böger, P

    1980-10-03

    The membrane-bound cytochrome f-556.5 from the blue-green alga Spirulina platensis was purified to apparent homogeneity. Most of its properties are comparable to cytochrome f isolated from higher plants and green algae. It is clearly distinguishable from soluble cytochrome c-554, also present in Spirulina, which probably replaces the function of plastocyanin in photosynthetic electron transport. 1. The reduced form of cytochrome f exhibits an asymmetrical alpha-band with a maximum at 556.5 nm, and a pronounced shoulder at 550 nm. The beta-, gamma and delta-bands coincide with those described for Scenedesmus cytochrome f-553, with maxima at 524 (532), 422, 331 and a protein peak at 276 nm. The maximum of ferricytochrome f is at 410.5 nm; there is no indication of a weak 695 nm band, described for soluble c-type cytochromes. The purest preparations had a delta/protein-peak ratio of 0.8; the gamma/alpha ratio was 7.3. Formation of a pyridine hemochromogen with a maximum at 550 nm indicated a c-type cytochrome. The molar extinction coefficient at 556.5 nm is 30200, the differential extinction coefficient 21 500. 2. The molecular weight determined by gel filtration or SDS-polyacrylamide gel electrophoresis is 33 000 and 34 000, respectively. 3. The redox properties differ from those described for other cytochromes f isolated from green algae and higher plants: the midpoint redox potential is significantly more negative (+318 mV, pH 7.0) and from pH 6 to 10 no pH dependence is observed. 4. The isoelectric point was determined at pH 3.95, which is more acidic as compared to other cytochromes f. 5. Comparison of the amino acid composition indicated a distant relationship to higher plant cytochrome f and a closer relationship to cytochrome f from green algae.

  13. Effect of various colors of light-emitting diodes (LEDs) on the biomass composition of Arthrospira platensis cultivated in semi-continuous mode.

    Science.gov (United States)

    Markou, Giorgos

    2014-03-01

    In the present study, semi-continuous cultivation of Arthrospira platensis using various colors of light-emitting diodes (LEDs) as artificial lighting was performed in order to study their effects on the biomass composition of A. platensis. The lowest biomass productivity was obtained with blue LED (4.68 mg l(-1) day(-1)), while the highest was obtained with pink and red LEDs (30.89 and 30.69 mg l(-1) day(-1), respectively). All biomass compound contents were affected by the different colors studied, except that of total carotenoids. The lowest phycocyanin content was observed in pink LED (8.2%) while the maximum in blue LED (17.6 ± 2.4%). Chlorophyll content was lowest in red LED (1.04%) and highest in blue LED (1.42%). The highest protein content was obtained with white and green LEDs (50.1 and 49.8%, respectively), while the lowest was obtained with blue LED (42.1%). Carbohydrate content was contrarily affected as that of proteins. The highest carbohydrate content was obtained in blue LED (11.3%) and the lowest under white and pink LEDs (8.8 and 8.8%, respectively). Lipid content seems to follow the same trend as that of carbohydrates; the highest lipid content was obtained in blue LED (6.0%), and the lowest was obtained under pink LED (3.8%).

  14. The AplI restriction-modification system in an edible cyanobacterium, Arthrospira (Spirulina) platensis NIES-39, recognizes the nucleotide sequence 5'-CTGCAG-3'.

    Science.gov (United States)

    Shiraishi, Hideaki; Tabuse, Yosuke

    2013-01-01

    The degradation of foreign DNAs by restriction enzymes in an edible cyanobacterium, Arthrospira platensis, is a potential barrier for gene-transfer experiments in this economically valuable organism. We overproduced in Escherichia coli the proteins involved in a putative restriction-modification system of A. platensis NIES-39. The protein produced from the putative type II restriction enzyme gene NIES39_K04640 exhibited an endonuclease activity that cleaved DNA within the sequence 5'-CTGCAG-3' between the A at the fifth position and the G at the sixth position. We designated this enzyme AplI. The protein from the adjacent gene NIES39_K04650, which encodes a putative DNA (cytosine-5-)-methyltransferase, rendered DNA molecules resistant to AplI by modifying the C at the fourth position (but not the C at the first position) in the recognition sequence. This modification enzyme, M.AplI, should be useful for converting DNA molecules into AplI-resistant forms for use in gene-transfer experiments. A summary of restriction enzymes in various Arthrospira strains is also presented in this paper.

  15. Influence of ammonium sulphate feeding time on fed-batch Arthrospira (Spirulina) platensis cultivation and biomass composition with and without pH control.

    Science.gov (United States)

    Rodrigues, Mayla Santos; Ferreira, Lívia Seno; Converti, Attilio; Sato, Sunao; de Carvalho, João Carlos Monteiro

    2011-06-01

    Previous work demonstrated that a mixture of NH(4)Cl and KNO(3) as nitrogen source was beneficial to fed-batch Arthrospira (Spirulina) platensis cultivation, in terms of either lower costs or higher cell concentration. On the basis of those results, this study focused on the use of a cheaper nitrogen source mixture, namely (NH(4))(2)SO(4) plus NaNO(3), varying the ammonium feeding time (T=7-15 days), either controlling the pH by CO(2) addition or not. A. platensis was cultivated in mini-tanks at 30°C, 156 μmol photons m(-2) s(-1), and starting cell concentration of 400 mg L(-1), on a modified Schlösser medium. T=13 days under pH control were selected as optimum conditions, ensuring the best results in terms of biomass production (maximum cell concentration of 2911 mg L(-1), cell productivity of 179 mg L(-1)d(-1) and specific growth rate of 0.77 d(-1)) and satisfactory protein and lipid contents (around 30% each).

  16. Characterization and pyrolysis of Chlorella vulgaris and Arthrospira platensis: potential of bio-oil and chemical production by Py-GC/MS analysis.

    Science.gov (United States)

    Almeida, Hanna N; Calixto, Guilherme Q; Chagas, Bruna M E; Melo, Dulce M A; Resende, Fabio M; Melo, Marcus A F; Braga, Renata Martins

    2017-06-01

    Biofuels have been seen as potential sources to meet future energy demand as a renewable and sustainable energy source. Despite the fact that the production technology of first-generation biofuels is consolidated, these biofuels are produced from foods crops such as grains, sugar cane, and vegetable oils competing with food for crop use and agricultural land. In recent years, it was found that microalgae have the potential to provide a viable alternative to fossil fuels as source of biofuels without compromising food supplies or arable land. On this scenario, this paper aims to demonstrate the energetic potential to produce bio-oil and chemicals from microalgae Chlorella vulgaris and Arthrospira platensis. The potential of these biomasses was evaluated in terms of physical-chemical characterization, thermogravimetric analysis, and analytical pyrolysis interfaced with gas chromatograph (Py-GC/MS). The results show that C. vulgaris and A. platensis are biomasses with a high heating value (24.60 and 22.43 MJ/kg) and low ash content, showing a high percentage of volatile matter (72.49 and 79.42%). These characteristics confirm their energetic potential for conversion process through pyrolysis, whereby some important aromatic compounds such as toluene, styrene, and phenol were identified as pyrolysis products, which could turn these microalgae a potential for biofuels and bioproduct production through the pyrolysis.

  17. Exploration of using stripped ammonia and ash from poultry litter for the cultivation of the cyanobacterium Arthrospira platensis and the green microalga Chlorella vulgaris.

    Science.gov (United States)

    Markou, Giorgos; Iconomou, Dimitris; Sotiroudis, Theodore; Israilides, Cleanthes; Muylaert, Koenraad

    2015-11-01

    Herein a new approach of exploiting poultry litter (PL) is demonstrated. The suggested method includes drying of PL with simultaneously striping and recovery of ammonia, followed by the direct combustion of dried PL. The generated ash after the combustion, and the striped ammonia consequently, could be used as nutrient source for the cultivation of microalgae or cyanobacteria to produce feed additives. The present study explored the application of PL ash and recovered ammonia for the cultivation of Arthrospira platensis and Chlorella vulgaris. For a simultaneously 90% dissolution of ash potassium and phosphorus, a ratio of acid to ash of 0.02mol-H(+)/g was required. The optimum mass of ash required was 0.07-0.08g/g dry biomass, while the addition of ammoniac nitrogen of 8-9mgN per g of dry biomass per day was adequate for a satisfactory production of A. platensis and C. vulgaris. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Burr Utility

    NARCIS (Netherlands)

    Ikefuji, M.; Laeven, R.J.A.; Magnus, J.R.; Muris, C.H.M.

    2010-01-01

    This note proposes the Burr utility function. Burr utility is a flexible two-parameter family that behaves approximately power-like (CRRA) remote from the origin, while exhibiting exponential-like (CARA) features near the origin. It thus avoids the extreme behavior of the power family near the origi

  19. Estimating Utility

    DEFF Research Database (Denmark)

    Arndt, Channing; Simler, Kenneth R.

    2010-01-01

    an information-theoretic approach to estimating cost-of-basic-needs (CBN) poverty lines that are utility consistent. Applications to date illustrate that utility-consistent poverty measurements derived from the proposed approach and those derived from current CBN best practices often differ substantially......, with the current approach tending to systematically overestimate (underestimate) poverty in urban (rural) zones....

  20. Amplification of perpendicular and parallel magnetic fields by cosmic ray currents

    Science.gov (United States)

    Matthews, J. H.; Bell, A. R.; Blundell, K. M.; Araudo, A. T.

    2017-08-01

    Cosmic ray (CR) currents through magnetized plasma drive strong instabilities producing amplification of the magnetic field. This amplification helps explain the CR energy spectrum as well as observations of supernova remnants and radio galaxy hotspots. Using magnetohydrodynamic simulations, we study the behaviour of the non-resonant hybrid (NRH) instability (also known as the Bell instability) in the case of CR currents perpendicular and parallel to the initial magnetic field. We demonstrate that extending simulations of the perpendicular case to 3D reveals a different character to the turbulence from that observed in 2D. Despite these differences, in 3D the perpendicular NRH instability still grows exponentially far into the non-linear regime with a similar growth rate to both the 2D perpendicular and 3D parallel situations. We introduce some simple analytical models to elucidate the physical behaviour, using them to demonstrate that the transition to the non-linear regime is governed by the growth of thermal pressure inside dense filaments at the edges of the expanding loops. We discuss our results in the context of supernova remnants and jets in radio galaxies. Our work shows that the NRH instability can amplify magnetic fields to many times their initial value in parallel and perpendicular shocks.

  1. The perpendicular magnetic anisotropy of CoPt/Au multilayer films

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, T. [Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States); Gao, L. [Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States); Zhang, R. [Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States); Nicholl, L. [Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States); Yan, M.L. [Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States); Sellmyer, D.J. [Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States); Liou, S.H. [Department of Physics and Astronomy and Center for Materials Research and Analysis, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States)]. E-mail: sliou@unl.edu

    2005-02-01

    We have studied the magnetic properties of Au (2 nm)/Co{sub 50}Pt{sub 50} (3 nm)/Au (2 nm) multilayer films prepared on amorphous Al{sub 2}O{sub 3}/Si and (0 0 1) MgO substrates. The as-deposited films on both substrates are magnetically soft with an FCC structure and exhibit a perpendicular anisotropy. After annealing at 500 deg. C, the sample on the Al{sub 2}O{sub 3}/Si substrate has become magnetically isotropic but the sample on the MgO substrate still has perpendicular anisotropy with FCT structure. This film deposited on the MgO substrate did not show a strong perpendicular anisotropy due to the diffusion of the Au and the (1 1 1) nucleation of initial Au layer. We can obtain a perpendicular anisotropy in the multilayer films without an initial Au layer on a (0 0 1) MgO substrate. After annealing at 400 deg. C, these films have L1{sub 0} phase with (0 0 1) texture and strong perpendicular anisotropy.

  2. Perpendicular magnetic anisotropy in composite MgO/CoFeB/Ta/[Co/Pd]n structures

    Science.gov (United States)

    Garcia-Vazquez, Valentin; Chang, Yao-Jen; Canizo-Cabrera, A.; Garzon-Roman, Abel; Wu, Te-ho

    2016-02-01

    The impact of a non-magnetic Ta spacer layer on the perpendicular magnetic anisotropy (PMA) of composite magnetic structures constituted by ultra-thin Co/Pd multilayers (MLs) and MgO/CoFeB was studied. Composite structures lacking a Ta layer present in-plane magnetic anisotropy. The strong perpendicular anisotropy observed in sole Co/Pd MLs is not sufficient to pull the magnetic moment out of the film plane, not even after annealing at 300 or 350 °C. PMA with squareness values close to unity and annealing stability up to 350 °C is observed after the insertion of an ultra-thin Ta layer. Our study demonstrates that Ta layer is essential for obtaining perpendicular magnetic axis in MgO/CoFeB/Ta/[Co/Pd]6. The exchange coupling between the MgO/CoFeB bilayer and the Co/Pd MLs is ferromagnetic with sharp switching characteristics. Perpendicular composite structures with sharp magnetization reversal and annealing stability are relevant in perpendicular CoFeB-based magnetic tunnel junctions for the development of gigabit-scale nonvolatile memory.

  3. Rational design of carboxyl groups perpendicularly attached to a graphene sheet: a platform for enhanced biosensing applications.

    Science.gov (United States)

    Bonanni, Alessandra; Chua, Chun Kiang; Pumera, Martin

    2014-01-01

    Graphene oxide (GO)-based materials offer great potential for biofunctionalization with applications ranging from biosensing to drug delivery. Such biofunctionalization utilizes specific functional groups, typically a carboxyl moiety, as anchoring points for biomolecule. However, due to the fact that the exact chemical structure of GO is still largely unknown and poorly defined (it was postulated to consist of various oxygen-containing groups, such as epoxy, hydroxyl, carboxyl, carbonyl, and peroxy in varying ratios), it is challenging to fabricate highly biofunctionalized GO surfaces. The predominant anchoring sites (i.e., carboxyl groups) are mainly present as terminal groups on the edges of GO sheets and thus account for only a fraction of the oxygen-containing groups on GO. Herein, we suggest a direct solution to the long-standing problem of limited abundance of carboxyl groups on GO; GO was first reduced to graphene and consequently modified with only carboxyl groups grafted perpendicularly to its surface by a rational synthesis using free-radical addition of isobutyronitrile with subsequent hydrolysis. Such grafted graphene oxide can contain a high amount of carboxyl groups for consequent biofunctionalization, at which the extent of grafting is limited only by the number of carbon atoms in the graphene plane; in contrast, the abundance of carboxyl groups on "classical" GO is limited by the amount of terminal carbon atoms. Such a graphene platform embedded with perpendicularly grafted carboxyl groups was characterized in detail by X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy, and its application was exemplified with single-nucleotide polymorphism detection. It was found that the removal of oxygen functionalities after the chemical reduction enhanced the electron-transfer rate of the graphene. More importantly, the introduction of carboxyl groups promoted a more efficient immobilization of DNA probes on the

  4. Large parallel and perpendicular electric fields on electron spatial scales in the terrestrial bow shock

    CERN Document Server

    Bale, S D

    2007-01-01

    Large parallel ($\\leq$ 100 mV/m) and perpendicular ($\\leq$ 600 mV/m) electric fields were measured in the Earth's bow shock by the vector electric field experiment on the Polar satellite. These are the first reported direct measurements of parallel electric fields in a collisionless shock. These fields exist on spatial scales comparable to or less than the electron skin depth (a few kilometers) and correspond to magnetic field-aligned potentials of tens of volts and perpendicular potentials up to a kilovolt. The perpendicular fields are amongst the largest ever measured in space, with energy densities of $\\epsilon_0 E^2/ n k_b T_e$ of order 10%. The measured parallel electric field implies that the electrons can be demagnetized, which may result in stochastic (rather than coherent) electron heating.

  5. Light scattering of rectangular slot antennas: parallel magnetic vector vs perpendicular electric vector.

    Science.gov (United States)

    Lee, Dukhyung; Kim, Dai-Sik

    2016-01-07

    We study light scattering off rectangular slot nano antennas on a metal film varying incident polarization and incident angle, to examine which field vector of light is more important: electric vector perpendicular to, versus magnetic vector parallel to the long axis of the rectangle. While vector Babinet's principle would prefer magnetic field along the long axis for optimizing slot antenna function, convention and intuition most often refer to the electric field perpendicular to it. Here, we demonstrate experimentally that in accordance with vector Babinet's principle, the incident magnetic vector parallel to the long axis is the dominant component, with the perpendicular incident electric field making a small contribution of the factor of 1/|ε|, the reciprocal of the absolute value of the dielectric constant of the metal, owing to the non-perfectness of metals at optical frequencies.

  6. Fabrication of MnAl thin films with perpendicular anisotropy on Si substrates

    Science.gov (United States)

    Huang, Efrem Y.; Kryder, Mark H.

    2015-05-01

    For the first time, perpendicularly magnetized L10-ordered MnAl thin films were demonstrated using a MgO seed layer on Si substrates, which is critical to making spintronic devices. Fabrication conditions were selected by systematically varying sputtering parameters (film thickness, DC sputtering power, in situ substrate temperature, and post-annealing temperature) and investigating structural and magnetic properties. Strong perpendicular magnetic anisotropy with coercivity Hc of 8 kOe, Ku of over 6.5 × 106 erg/cm3, saturation magnetization Ms of 300 emu/cm3, and out-of-plane squareness Mr/Ms of 0.8 were achieved. These MnAl film properties were obtained via DC magnetron sputtering at 530 °C, followed by 350 °C annealing under a 4 kOe magnetic field oriented perpendicular to the film plane.

  7. Annealing effect on perpendicular [CoFe /Pd]{sub n} multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Feng, J F; Coey, J M D, E-mail: jfeng@tcd.ie [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)

    2011-07-06

    Perpendicular magnetic anisotropy is investigated in [CoFe/Pd]{sub n} multilayers grown on Si/SiO{sub 2} substrates. Coercivity is measured for [CoFe(t{sub 1})/Pd(t{sub 2})]{sub n} multilayers with t{sub 1} = 0.4 or 0.5 nm when t{sub 2} varies from 0.4 to 2.7 nm. Furthermore, there is an enhancement of the perpendicular anisotropy on increasing the thickness of the Pd layer and the annealing temperature. We also compare the [CoFe/Pd]{sub n} multilayers to those made with a thin CoFeB layer in contact with Pd inserted at the top or bottom of the [CoFe/Pd]{sub n} stacks. The perpendicular magnetic anisotropy is maintained.

  8. High perpendicular magnetic anisotropy in D022-Mn3+xGe tetragonal Heusler alloy films

    Science.gov (United States)

    Sugihara, A.; Mizukami, S.; Yamada, Y.; Koike, K.; Miyazaki, T.

    2014-03-01

    We prepared D022-Mn3+xGe (-0.67 ≤ x ≤ 0.35) epitaxial thin films on MgO(001) substrates with Cr(001) buffer layers and systematically investigated the dependence of their perpendicular magnetic anisotropy constant, saturation magnetization, coercivity, and tetragonal axial ratio (c/a) on their composition and substrate temperature. Single-phase D022 crystal structures were formed in films with compositions of 0 ≤ x ≤ 0.35, prepared at 400 °C. The D022-Mn3Ge films exhibited perpendicular magnetization with a magnetic squareness close to unity. Performing magnetic torque measurements at an applied field of 140 kOe, we estimated a perpendicular magnetic anisotropy constant of 11.8 ± 0.5 Merg/cm3, the highest and the most reliable value yet reported.

  9. Perpendicular magnetic anisotropy and structural properties of NiCu/Cu multilayers

    Science.gov (United States)

    Ruotolo, A.; Bell, C.; Leung, C. W.; Blamire, M. G.

    2004-07-01

    Perpendicular magnetic anisotropy (PMA) was studied at low temperature (T=30 K) in dc-magnetron sputtered Ni60Cu40/Cu multilayers. PMA has been observed in many multilayer structures for ferromagnetic layer thicknesses less than a certain thickness t⊥. In general cases t⊥ is less than a few nanometers, making such structures unsuitable for low-cost fabrication techniques. Our results show a strong perpendicular easy direction of magnetization for NiCu layer thickness between 4.2 nm and 34 nm. The thickness t⊥ at which the multilayers change the preferential orientation from perpendicular to in-plane is estimated to be 55 nm. Structural studies show that the low magnetostatic energy density is likely to be the main reason for the large t⊥ value obtained in this system.

  10. Energy Conversion Mechanism for Electron Perpendicular Energy in High Guide-Field Reconnection

    Science.gov (United States)

    Guo, Xuehan; Horiuchi, Ritoku; Kaminou, Yasuhiro; Cheng, Frank; Ono, Yasushi

    2016-10-01

    The energy conversion mechanism for electron perpendicular energy, both the thermal and the kinetic energy, is investigated by means of two-dimensional, full-particle simulations in an open system. It is shown that electron perpendicular heating is mainly due to the breaking of magnetic moment conservation in separatrix region because the charge separation generates intense variation of electric field within the electron Larmor radius. Meanwhile, electron perpendicular acceleration takes place manly due to the polarization drift term as well as the curvature drift term of E . u⊥ in the downstream near the X-point. The enhanced electric field due to the charge separation there results in a significant effect of the polarization drift term on the dissipation of magnetic energy within the ion inertia length in the downstream. Japan Society for the Promotion of Science (JSPS) Fellows 15J03758.

  11. Giant perpendicular magnetic anisotropy of an individual atom on two-dimensional transition metal dichalcogenides

    Science.gov (United States)

    Odkhuu, Dorj

    2016-08-01

    Exploring magnetism and magnetic anisotropy in otherwise nonmagnetic two-dimensional materials, such as graphene and transition metal dichalcogenides, is at the heart of spintronics research. Herein, using first-principles calculations we explore the possibility of reaching an atomic-scale perpendicular magnetic anisotropy by carefully exploring the large spin-orbit coupling, orbital magnetism, and ligand field in a suitable choice of a two-dimensional structure with transition metal adatoms. More specifically, we demonstrate perpendicular magnetic anisotropy energies up to an order of 100 meV per atom in individual ruthenium and osmium adatoms at a monosulfur vacancy in molybdenum disulfide. We further propose a phenomenological model where a spin state transition that involves hybridization between molybdenum a1 and adatomic e' orbitals is a possible mechanism for magnetization reversal from an in-plane to perpendicular orientation.

  12. Tuneable perpendicular magnetic anisotropy in single crystal [Co/Ni](111) superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Gottwald, M; Girod, S; Andrieu, S; Mangin, S, E-mail: gottwald@lpm.u-nancy.fr [Institut Jean Lamour, CNRS - Nancy Universite, BP 239, F-54506 Vandoeuvre (France)

    2010-06-15

    This paper is dedicated to the preparation of thin film with a strong perpendicular to the film plane magnetic anisotropy, behaviour of great interest for spintronics. Single-crystalline [Co/Ni] (111) superlattices have been grown by molecular beam epitaxy. The epitaxial growth of Co and Ni was controlled by using reflection high energy diffraction (RHEED), allowing us to get an accurate control of the thicknesses. The superlattices magnetic properties were studied using magnetometry. All of them exhibit strong perpendicular to the plane magnetic anisotropy. The maximum of magneto-crystalline anisotropy is obtained for one cobalt mo nolayer. A simple model which takes into account surface and volume anisotropy explains the evolution of perpendicular anisotropy in these layers.

  13. The absorption and transformation of Na2SeO3into nano elemental selenium by Spirulina platensis%钝顶螺旋藻(Spirulina platensis)吸收转化亚硒酸钠生成纳米元素硒

    Institute of Scientific and Technical Information of China (English)

    周永林; 任璐艳; 靳兴媛; 张逸波; 凌钦婕; 黄峙

    2012-01-01

    对钝顶螺旋藻(Spinlina platersis)富硒培养过程中转化亚硒酸钠产生的红色纳米元素硒(Nano-Se)进行鉴定和分析.原子力显微镜( AFM)观测红色微粒的纳米形貌,激光散射仪分析其粒径分布,透射电镜(TEM)和X-线能谱(EDX)联用表征纳米粒中的元素硒形态,电感耦合等离子质谱仪(ICP-MS)测定Nano-Se中的金属元素构成和含量,回归分析螺旋藻细胞总蛋白含量及还原性巯基水平与转化Nano-Se生成量的相关性.结果发现从富硒螺旋藻培养液和细胞裂解液中分离鉴定到Nano-Se,其为较均一的球形或近似球形,平均粒径约60nm,其中硒的质量比为58.5%,原子比为34.7%,除主要含硒元素外,也含有微量的Cu、Zn、Fe、Mn和Ca等元素,并含有少量蛋白质.还发现Nano-Se的生成与藻细胞总蛋白和还原性巯基水平呈明显负相关.实验结果表明,螺旋藻可转化亚硒酸钠生成Nano-Se,为富硒微藻中活性硒形态的研究及工业生产提供理论根据.%Nano elemental selenium (Nano-Se) was bio-transformed by Spirulina platensis (S. plat-ensis ) with supplementation of sodium selenite [p( Se) = 300 μg/mL] in culture medium for 9 days. The shape and size of Nano-Se was characterized by atomic force microscope ( AFM), laser light scattering spectroscopy (LSS) and transmission electron microcope (TEM) combined with energy-dispersive X-ray ( EDX). Contents of metal elements in Nano-Se were detected by inductively coupled plasma mass spec-trometry (ICP-MS). Correlations of total protein and non-reduced sulfhydryl groups in S. platensis with Nano-Se production were also analyzed. Present findings have shown that the shape of Nano-Se is spheri-cal in high homogeneous with average diameter of 60 run. The relative mass ratio and atomic ratio of Se in the Nano-Se was 58. 5% and 34.1% , respectively. Furthermore, Nano-Se contains some other detecta-ble metal elements including Cu, Zn, Fe, Mn and Ca, as well as a low

  14. Perpendicular magnetic anisotropy in CoXPd100-X alloys for magnetic tunnel junctions

    Science.gov (United States)

    Clark, B. D.; Natarajarathinam, A.; Tadisina, Z. R.; Chen, P. J.; Shull, R. D.; Gupta, S.

    2017-08-01

    CoFeB/MgO-based perpendicular magnetic tunnel junctions (p-MTJ's) with high anisotropy and low damping are critical for spin-torque transfer random access memory (STT-RAM). Most schemes of making the pinned CoFeB fully perpendicular require ferrimagnets with high damping constants, a high temperature-grown L10 alloy, or an overly complex multilayered synthetic antiferromagnet (SyAF). We report a compositional study of perpendicular CoxPd alloy-pinned Co20Fe60B20/MgO based MTJ stacks, grown at moderate temperatures in a planetary deposition system. The perpendicular anisotropy of the CoxPd alloy films can be tuned based on the layer thickness and composition. The films were characterized by alternating gradient magnetometry (AGM), energy-dispersive X-rays (EDX), and X-ray diffraction (XRD). Current-in-plane tunneling (CIPT) measurements have also been performed on the compositionally varied CoxPd MTJ stacks. The CoxPd alloy becomes fully perpendicular at approximately x = 30% (atomic fraction) Co. Full-film MTJ stacks of Si/SiO2/MgO (13)/CoXPd100-x (50)/Ta (0.3)/CoFeB (1)/MgO (1.6)/CoFeB (1)/Ta (5)/Ru (10), with the numbers enclosed in parentheses being the layer thicknesses in nm, were sputtered onto thermally oxidized silicon substrates and in-situ lamp annealed at 400 °C for 5 min. CIPT measurements indicate that the highest TMR is observed for the CoPd composition with the highest perpendicular magnetic anisotropy.

  15. Magnetic stripes and holes: Complex domain patterns in perforated films with weak perpendicular anisotropy

    Directory of Open Access Journals (Sweden)

    F. Valdés-Bango

    2017-05-01

    Full Text Available Hexagonal antidot arrays have been patterned on weak perpendicular magnetic anisotropy NdCo films by e-beam lithography and lift off. Domain structure has been characterized by Magnetic Force Microscopy at remanence. On a local length scale, of the order of stripe pattern period, domain configuration is controlled by edge effects within the stripe pattern: stripe domains meet the hole boundary at either perpendicular or parallel orientation. On a longer length scale, in-plane magnetostatic effects dominate the system: clear superdomains are observed in the patterned film with average in-plane magnetization along the easy directions of the antidot array, correlated over several antidot array cells.

  16. Induced moment due to perpendicular field cycling in trained exchange bias system

    Indian Academy of Sciences (India)

    Amithesh Paul; S Mattauch

    2013-04-01

    Depth-sensitive polarized neutron scattering in specular and off-specular mode has recently revealed that perpendicular field cycling brings about a modification in the interfacial magnetization of a trained exchange coupled interface. We show here by various model fits to our neutron reflectivity data that a restoration of the untrained state is not possible in the case of our polycrystalline multilayer specimen. This is due to the magnetic moment at the interface induced only after perpendicular field cycling, changing the initial field-cooled state.

  17. Magnetic properties of soft layer/FePt-MgO exchange coupled composite Perpendicular recording media

    Institute of Scientific and Technical Information of China (English)

    Yin Jin-Hua; Takao Suzuki; Pan Li-Qing

    2008-01-01

    The magnetic properties of exchange coupled composite(ECC)media that are composed of perpendicular magnetic recording media FePt-MgO and two kinds of soft layers have been studied by using an x-ray diffractometer,a polar Kerr magneto-optical system(PMOKE)and a vibrating sample magnetometer(VSM).The results show that ECC media can reduce the coercivities of perpendicular magnetic recording media FePt-MgO.The ECC media with granular-type soft layers have weaker exchange couplings between magnetic grains and the magnetization process,for ECC media of this kind mainly follow the Stoner-Wohlfarth model.

  18. Analysis of mode III crack perpendicular to the interface between two dissimilar strips

    Institute of Scientific and Technical Information of China (English)

    M. S. Matbuly

    2008-01-01

    The present work is concerned with the problem of mode III crack perpendicular to the interface of a bi-strip composite. One of these strips is made of a functionally graded material and the other of an isotropic material, which contains an edge crack perpendicular to and terminating at the interface. Fourier transforms and asymptotic analysis are employed to reduce the problem to a singular integral equation which is numerically solved using Gauss-Chebyshev quadrature formulae. Furthermore, a parametric study is carried out to investigate the effects of elastic and geometric characteristics of the composite on the values of stress intensity factor.

  19. Temperature dependence of microwave oscillations in magnetic tunnel junctions with a perpendicularly magnetized free layer

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Peng; Feng, Jiafeng, E-mail: hxwei@iphy.ac.cn, E-mail: jiafengfeng@iphy.ac.cn; Wei, Hongxiang, E-mail: hxwei@iphy.ac.cn, E-mail: jiafengfeng@iphy.ac.cn; Han, Xiufeng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Fang, Bin; Zhang, Baoshun; Zeng, Zhongming [Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Ruoshui Road 398, Suzhou 215123 (China)

    2015-01-05

    We experimentally study the temperature dependence of the spin-transfer-torque-induced microwave oscillations in MgO-based magnetic tunnel junction nanopillars with a perpendicularly magnetized free layer. We demonstrate that the oscillation frequency increases rapidly with decreasing temperature, which is mainly ascribed to the temperature dependence of both the saturation magnetization and the perpendicular magnetic anisotropy. We also find that a strong temperature dependence of the output power while a nonmonotonic temperature dependence of spectral linewidth are maintained for a constant dc bias in measured temperature range. Possible mechanisms leading to the different dependences of oscillation frequency, output power, and linewidth are discussed.

  20. Engineering spin-orbit torque in Co/Pt multilayers with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kuo-Feng; Wang, Ding-Shuo; Lai, Chih-Huang, E-mail: chlai@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lin, Hsiu-Hau [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2015-12-07

    To address thermal stability issues for spintronic devices with a reduced size, we investigate spin-orbit torque in Co/Pt multilayers with strong perpendicular magnetic anisotropy. Note that the spin-orbit torque arises from the global imbalance of the spin currents from the top and bottom interfaces for each Co layer. By inserting Ta or Cu layers to strengthen the top-down asymmetry, the spin-orbit torque efficiency can be greatly modified without compromised perpendicular magnetic anisotropy. Above all, the efficiency builds up as the number of layers increases, realizing robust thermal stability and high spin-orbit-torque efficiency simultaneously in the multilayers structure.

  1. Analytic theory of wall configuration and depinning mechanism in magnetic nanostructure with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kab-Jin [School of Physics, Seoul National University, Seoul 151-742 (Korea, Republic of); Choe, Sug-Bong [School of Physics, Seoul National University, Seoul 151-742 (Korea, Republic of)], E-mail: sugbong@snu.ac.kr

    2009-07-15

    We present an analytic theory of the domain wall depinning in magnetic nanostructure with perpendicular magnetic anisotropy. The variational principle reveals that the wall is bent in the form of a circular arc which intersects the structure boundaries perpendicularly. The radius is inversely proportional to the magnetic field. With increasing the field the radius shrinks, followed by depinning from the constriction when the arc is not geometrically allowed. The depinning field is proportional to the sine of the constriction angle and the inverse of the constriction width. The validity of the theory is confirmed by comparison with the micromagnetic simulation.

  2. Engineering spin-orbit torque in Co/Pt multilayers with perpendicular magnetic anisotropy

    Science.gov (United States)

    Huang, Kuo-Feng; Wang, Ding-Shuo; Lin, Hsiu-Hau; Lai, Chih-Huang

    2015-12-01

    To address thermal stability issues for spintronic devices with a reduced size, we investigate spin-orbit torque in Co/Pt multilayers with strong perpendicular magnetic anisotropy. Note that the spin-orbit torque arises from the global imbalance of the spin currents from the top and bottom interfaces for each Co layer. By inserting Ta or Cu layers to strengthen the top-down asymmetry, the spin-orbit torque efficiency can be greatly modified without compromised perpendicular magnetic anisotropy. Above all, the efficiency builds up as the number of layers increases, realizing robust thermal stability and high spin-orbit-torque efficiency simultaneously in the multilayers structure.

  3. Cultivation of Arthrospira (spirulina) platensis in desalinator wastewater and salinated synthetic medium: protein content and amino-acid profile Cultivo de Arthrospira (Spirulina) platensis em rejeito de dessalinizador e meio sintético salinizado: teor protéico e perfil de aminoácidos

    OpenAIRE

    Harriet Volkmann; Ulisses Imianovsky; Jorge L.B. Oliveira; Ernani S. Sant'Anna

    2008-01-01

    Arthrospira (Spirulina) platensis was cultivated in laboratory under controlled conditions (30ºC, photoperiod of 12 hours light/dark provided by fluorescent lamps at a light intensity of 140 µmol photons.m-2.s-1 and constant bubbling air) in three different culture media: (1) Paoletti medium (control), (2) Paoletti supplemented with 1 g.L-1 NaCl (salinated water) and (3) Paoletti medium prepared with desalinator wastewater. The effects of these treatments on growth, protein content and amino ...

  4. VIABILIDADE DE BACTÉRIAS LÁTICAS EM IOGURTE ADICIONADO DE BIOMASSA DA MICROALGA Spirulina platensis DURANTE O ARMAZENAMENTO REFRIGERADO

    Directory of Open Access Journals (Sweden)

    K. J. PEREZ

    2008-11-01

    Full Text Available

    A influência de longos períodos de estocagem sobre a contagem de bactérias láticas viáveis tem sido estudada, uma vez que os produtos lácteos fermentados devem possuir um número mínimo de microrganismos, a partir do qual apresentam efeitos benéficos ao consumidor. A adição de biomassa seca da microalga Spirulina platensis pode influenciar beneficamente a sobrevivência das bactérias iniciadoras durante o armazenamento refrigerado, devido à sua composição em proteínas, vitaminas, aminoácidos essenciais, minerais e ácidos graxos essenciais como ácido - linolênico. Objetivou-se avaliar a viabilidade celular das bactérias láticas sob refrigeração em iogurtes preparados com e sem a adição de extrato seco da microalga Spirulina. O iogurte foi elaborado sob condições assépticas e dividido em três amostras: controle, com adição de 0,5 e 1,0 % de biomassa da microalga Spirulina seca. Estas amostras foram armazenadas a 4ºC durante 0, 15 e 30 dias, sendo realizadas contagens de bactérias láticas nestes períodos. A adição de biomassa de Spirulina platensis influenciou positivamente a sobrevivência das bactérias ácido-láticas durante o armazenamento refrigerado, diminuindo a perda de viabilidade durante os 30 dias de armazenamento refrigerado para as amostras adicionadas de 1,0 % de biomassa de Spirulina platensis.

  5. CO2 Sequestration by Spirulina Platensis%钝顶螺旋藻固定二氧化碳效率的研究

    Institute of Scientific and Technical Information of China (English)

    王霞; 张涛; 童丹

    2015-01-01

    Gas Chromatograph Mass Spectrometer was used to evaluate the efficiency of CO 2 sequestration by the blue green alga Spirulina platensis in a closed photobioreactor cascade.It was found that Sp .plat-ensis culture emitted large quantity of CO 2 in the first a few days of the experiments,and then started CO 2 sequestration process.The emission of CO 2 was,presumably,caused by the combination of high concen-tration of NaHCO 3 and a pH value below 10.During theCO 2 sequestration process,the single photobiore-actor only assimilated ~ 40% of atmospheric CO 2 .Sp .platensis grew normally in this photobioreactor cascade with an average productivity of 0.14 g/L/d.The technology method provides a theoretical basis for purifing a high concentration of CO 2 in the coal-fired industries,and it can also achieve a high economic value of Spirulina products.Therefore,CO 2 sequestration by Spirulina is of great significance in the en-ergy industry,environmental protection and recycling economy.%采用气质联用仪测量 CO 2浓度,研究户外密闭条件下钝顶螺旋藻固定 CO 2的情况.实验结果表明,培养基中 NaHCO 3浓度较高及 pH 低于10时,试验第0~3天有大量 CO 2从培养基中溢出,之后藻液开始固定空气中CO 2.整个自制光生物反应器固定 CO 2量约为326 mg/(L.d),而单一反应器藻液固定 CO 2效率约为40%,其平均增重约0.14 g/(L.d).该技术能为净化燃煤工业废气中高浓度 CO 2提供理论依据,同时还可获得高经济价值的螺旋藻产品.

  6. C02 fixation in simulated flue gas by Spirulina platensis%钝顶螺旋藻固定模拟烟道气中的CO_2

    Institute of Scientific and Technical Information of China (English)

    王磊; 任洪艳; 缪恒锋; 阮文权

    2012-01-01

    研究了钝顶螺旋藻对模拟烟道气中CO2的固定性能,及其对NOx和SOx水溶形态亚硝态氮、亚硫酸氢根的耐受性。结果显示:随CO2浓度的增加,藻细胞达到最大比生长速率的时间缩短,CO2浓度为15%时藻细胞比生长速率达到最大的时间最短,生物量最终达到最大值4.1 g/L;CO2浓度为15%时藻细胞的固碳率为12.34 mg/(L·h)。研究发现,钝顶螺旋藻能够耐受浓度小于10 mmol/L的亚硝态氮,可将其作为钝顶螺旋藻生长的唯一氮源,但藻生长的延迟期增长。钝顶螺旋藻能够耐受8 mmol/L的亚硫酸氢盐,可将其作为生长的唯一硫源,藻细胞6 d后开始快速增长。%The capability of carbon fixation in simulated flue gas and the tolerance to water-soluble nitrite and bisulfite were investigated. The results showed that with the increase of CO2 concentration, the time that the algae cell grew to the maximum specific growth rate could be shortened at a higher CO2 concentration. The time was shortest at the 15% CO2 and the final biomass of Spirulina platensis was 4.1 g/L. The carbon fixation rate was 12.34 mg/(L ~ h) at the 15% CO2. The growth of Spirulina platensis can tolerate the nitrite with the con- tent lower than 10 mmol/L, which could be as the only nitrogen source, while the lag phase was prolonged by studies. Spirulina platensis can tolerate the bisulfite with content lower than 8 mmol/L and bisulfite can be as the sole sulfur source,the algae grew rapidly after the cultivation of 6 d.

  7. Study of polyethyleneimine- and amidoxime-functionalized hybrid biomass of Spirulina (Arthrospira) platensis for adsorption of uranium (VI) ion.

    Science.gov (United States)

    Bayramoglu, Gulay; Akbulut, Aydin; Arica, M Yakup

    2015-11-01

    This study investigates the potential application of the polyethyleneimine- (PEI) and amidoxime-modified Spirulina (Arthrospira) platensis biomasses for the removal of uranium ion in batch mode using the native biomass as a control system. The uranium ion adsorption was also characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra, zeta potential analysis, and surface area measurement studies. The effects of pH, biomass amount, contact time, initial uranium ion concentration, and ionic strength were evaluated by using native and modified algal biomass preparations. The uranium ion removal was rapid, with more than 70% of total adsorption taking place in 40 min, and equilibrium was established within 60 min. From the experimental data, it was found that the amount of adsorption uranium ion on the algal preparations decreased in the following series: amidoxime-modified algal biomass > PEI-modified algal biomass > native algal biomass. Maximum adsorption capacities of amidoxime- and PEI-modified, and native algal biomasses were found to be 366.8, 279.5, and 194.6 mg/g, respectively, in batchwise studies. The adsorption rate of U(VI) ion by amidoxime-modified algal biomass was higher than those of the native and PEI-modified counterparts. The adsorption processes on all the algal biomass preparations followed by the Dubinin-Radushkevitch (D-R) and Temkin isotherms and pseudo-second-order kinetic models. The thermodynamic parameters were determined at four different temperatures (i.e., 15, 25, 35, and 45 °C) using the thermodynamics constant of the Temkin isotherm model. The ΔH° and ΔG° values of U(VI) ion adsorption on algal preparations show endothermic heat of adsorption; higher temperatures favor the process. The native and modified algal biomass preparations were regenerated using 10 mM HNO3. These results show that amidoxime-modified algal biomass can be a potential candidate for effective removal of U(VI) ion from

  8. Extraction of spirulina platensis polysaccharide by ethanol/(NH4)2SO4 aqueous two-phase system%乙醇/硫酸铵双水相体系萃取螺旋藻多糖的研究

    Institute of Scientific and Technical Information of China (English)

    刘杨; 冯元琦; 陈美欣; 吴景淳; 黄海根

    2012-01-01

    Extraction of spirulina platensis polysaccharide by ethanol/( NH4 ) 2SO4 aqueous two-phase system(ATPS)was investigated. To remove and recycle the proteins, salting-out precipitation protein was carried out after spirulina platensis cells disruption. Spirulina platensis polysaccharide was extracted by traditional hot water diffusion and the polysaccharide dissolution rate reached 38.44 ± 1. 12mg/g spirulina platensis powder. Spirulina platensis polysaccharide was purified deeply by ethanol/ (NH4)2SO4 ATPS. The yield and enrichment factor of the polysaccharide were 84. 5±1. 45% and 6. 2 respectively,on the condition that the tie line length, volume ratio and pH of ATPS were 42. 9,1. 05 and 7. 0, respectively. The results indicated that spirulina platensis polysaccharide would be purified by a simple, efficient and low cost extraction technology using inexpensive ethanol/ (NH4)2SO4 ATPS.%考察了低分子有机溶剂与无机盐-乙醇/硫酸铵双水相体系萃取螺旋藻多糖的可行性及影响因素.研究结果表明:为除去并有效回收螺旋藻细胞中的蛋白质成分,在藻细胞破碎后进行盐析沉淀蛋白质,再采用传统的热水浸提法,可得到螺旋藻多糖的溶出率为38.44±1.12mg/g干燥粉;通过乙醇/硫酸铵双水相体系的萃取分配,在w(乙醇)=19%,w(硫酸铵)=27.5%(即双水相体系系线长度TLL =42.9),体系相比VR=1.05,pH=7.0时,螺旋藻多糖的收率可达84.5±1.45%,富集因子可达6.2.该研究结果表明廉价的乙醇/硫酸铵双水相萃取螺旋藻多糖将有望开发成为一条简洁、高效、低成本的螺旋藻多糖分离提取工艺.

  9. Enhancement of perpendicular magnetic anisotropy of Co layer in exchange-biased Au/Co/NiO/Au polycrystalline system

    Science.gov (United States)

    Kuświk, P.; Szymański, B.; Anastaziak, B.; Matczak, M.; Urbaniak, M.; Ehresmann, A.; Stobiecki, F.

    2016-06-01

    The perpendicular exchange bias in NiO(antiferromagnet)/Co(ferromagnet) polycrystalline layer films is studied. It is found that the NiO layer forces the Co layer magnetization to be oriented perpendicular to the film plane in a greater thickness range than is found in the Au/Co/Au system. Simultaneously, a large coercivity and a significant perpendicular exchange bias field were observed that are owing to the interlayer exchange bias coupling between NiO and Co, which supports the perpendicular magnetic anisotropy of the Co layer. These findings are confirmed by magnetometry and magnetoresistance measurements.

  10. Perpendicular Diffusion Coefficient of Comic Rays: The Presence of Weak Adiabatic Focusing

    Science.gov (United States)

    Wang, J. F.; Qin, G.; Ma, Q. M.; Song, T.; Yuan, S. B.

    2017-08-01

    The influence of adiabatic focusing on particle diffusion is an important topic in astrophysics and plasma physics. In the past, several authors have explored the influence of along-field adiabatic focusing on the parallel diffusion of charged energetic particles. In this paper, using the unified nonlinear transport theory developed by Shalchi and the method of He and Schlickeiser, we derive a new nonlinear perpendicular diffusion coefficient for a non-uniform background magnetic field. This formula demonstrates that the particle perpendicular diffusion coefficient is modified by along-field adiabatic focusing. For isotropic pitch-angle scattering and the weak adiabatic focusing limit, the derived perpendicular diffusion coefficient is independent of the sign of adiabatic focusing characteristic length. For the two-component model, we simplify the perpendicular diffusion coefficient up to the second order of the power series of the adiabatic focusing characteristic quantity. We find that the first-order modifying factor is equal to zero and that the sign of the second order is determined by the energy of the particles.

  11. Quasi interference of perpendicularly polarized guided modes observed with a photon scanning tunneling microscope

    NARCIS (Netherlands)

    Balistreri, M.L.M.; Driessen, A.; Korterik, Jeroen P.; Kuipers, L.; van Hulst, N.F.

    2000-01-01

    The simultaneous detection of TE- as well as TM-polarized light with a photon scanning tunneling microscope leads to a quasi- interference pattern of these mutually perpendicular polarized fields. This interference pattern has been observed in the optical field distribution as a function of both pos

  12. Magnetic structures in Co---Cr media for perpendicular magnetic recording

    NARCIS (Netherlands)

    Lodder, J.C.

    1996-01-01

    High bit densities have been demonstrated in longitudinal as well as in perpendicular magnetic recording. For the latter an area density of more than 12 Gbit/in2 has been obtained in a sputtered Co---Cr---Ta hard disk with a soft magnetic underlayer recorded with a special single pole head. In this

  13. A new method for intrinsic viscosity measurements on perpendicular recording media

    NARCIS (Netherlands)

    Phan le kim, P.L.K.; Lodder, J.C.

    2002-01-01

    Summary form only given. In the case of perpendicular media, it is hard to measure the magnetic viscosity S (from the relaxation curve) because the internal field (H/sub 1/) is continuously changing with time due to the change in the demagnetizing field. Correction for this effect using an

  14. On the Relationship between Magnetic Viscosity and Coercivity of Perpendicular Media

    NARCIS (Netherlands)

    te Lintelo, J.G.Th.; te Lintelo, J.G.T.; Lodder, J.C.

    1994-01-01

    The dependent and dc-demagnetization measurements were performed on two types of perpendicular thin film media, Co-Cr and Fe-alumite. From these the parameters for magnetic viscosity and irreversible susceptibility were derived. Their ratio, resulting in the fluctuation field, is shown to relate

  15. Time-Dependence effect in alumite recording media with perpendicular anisotropy

    NARCIS (Netherlands)

    Phan le kim, P.L.K.; Lodder, J.C.

    1999-01-01

    In this paper, we will present a study of the time-dependence effect in alumite perpendicular media at different thicknesses. Important parameters of the time-dependence effect such as magnetic viscosity and activation volume are investigated. Viscosity as a function of applied field (viscosity

  16. Magnetic domains in epitaxial BaFe12O19 thin films with perpendicular anisotropy

    NARCIS (Netherlands)

    Lisfi, A.; Lodder, J.C.

    2002-01-01

    Magnetic domains, microstructure and magnetic properties of highly oriented barium ferrite thin films with perpendicular anisotropy have been investigated with magnetic force microscopy (MFM), VSM, SEM and TEM. Two kinds of magnetic domain are energetically favourable: (a) cluster-like structure in

  17. Spin-dependent Peltier effect of perpendicular currents in multilayered nanowires

    Science.gov (United States)

    Gravier, Laurent; Serrano-Guisan, Santiago; Reuse, François; Ansermet, J.-Ph.

    2006-02-01

    Heat and charge transport perpendicular to Co/Cu multilayers are characterized by magnetoresistance and magnetothermoelectrical power. Furthermore, a very large voltage response to temperature oscillations under a dc current is observed, which depends strongly on the applied magnetic field. This effect is ascribed to a Peltier effect and its field dependence to a spin dependence of the Peltier coefficient.

  18. Magnetron sputtering deposition of [FePt/Ag]n multilayers for perpendicular recording

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    [FePt/Ag]n multilayers were deposited on glass substrates by RF magnetron sputtering and ex situ annealed at 550℃ for 30 min. The effects of inserted Ag layer thickness and the number of bilayer repetitions (n) on the structure and magnetic properties of the multilayers were investigated. It was found that the difference between in-plane and out-of-plane coercivities varied with an increase of inserted Ag layer thickness in the [FePt 2 nm/Ag x nm]10 multilayers. The ratio of out-of-plane coercivity to in-plane coercivity reached the maximum value with the Ag layer thickness of 5 nm, indicating that the Ag layer thickness plays an important role in obtaining perpendicular orientation. For the [FePt 2 nm/Ag 5 nm]n multilayers, perpendicular orientation is also influenced by n. The maximum value of the ratio of out-of-plane coercivity to in-plane coercivity appeared when n was given as 8. It was found that the [FePt 2 nm/Ag 5 nm]8 had a high perpendicular coercivity of 520 kA/m and a low in-plane one of 88 kA/m, which shows a strong perpendicular anisotropy.

  19. A comprehensive comparison of perpendicular distance sampling methods for sampling downed coarse woody debris

    Science.gov (United States)

    Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine; Michael S. Williams

    2013-01-01

    Many new methods for sampling down coarse woody debris have been proposed in the last dozen or so years. One of the most promising in terms of field application, perpendicular distance sampling (PDS), has several variants that have been progressively introduced in the literature. In this study, we provide an overview of the different PDS variants and comprehensive...

  20. Copper dusting effects on perpendicular magnetic anisotropy in Pt/Co/Pt tri-layers

    Directory of Open Access Journals (Sweden)

    Vineeth Mohanan Parakkat

    2016-05-01

    Full Text Available The effect of Cu dusting on perpendicular magnetic anisotropy of sputter grown Pt/Co/Pt stack in which the Cu layer is in proximity with that of Co is investigated in this work. We used magneto optic Kerr effect microscopy measurements to study the variation in the reversal mechanisms in films with Co thicknesses below 0.8nm by systematically varying their perpendicular magnetic anisotropy using controlled Cu dusting. Cu dusting was done separately above and below the cobalt layer in order to understand the role of bottom and top Pt layers in magnetization reversal mechanisms of sputtered Pt/Co/Pt stack. The introduction of even 0.3nm thick Cu layer below the cobalt layer drastically affected the perpendicular magnetic anisotropy as evident from the nucleation behavior. On the contrary, even a 4nm thick top Cu layer had little effect on the reversal mechanism. These observations along with magnetization data was used to estimate the role of top and bottom Pt in the origin of perpendicular magnetic anisotropy as well as magnetization switching mechanism in Pt/Co/Pt thin films. Also, with an increase in the bottom Cu dusting from 0.2 to 0.4nm there was an increase in the number of nucleation sites resulting in the transformation of domain wall patterns from a smooth interface type to a finger like one and finally to maze type.

  1. Heat assisted magnetic probe recording onto a thin film with perpendicular magnetic anisotropy

    NARCIS (Netherlands)

    Onoue, T.; Siekman, M.H.; Abelmann, L.; Lodder, J.C.

    2008-01-01

    The possibility of magnetic probe recording into a continuous perpendicular medium is discussed. By applying a current from the tip to the medium, a very localized area can be heated and bits as small as 80 nm in diameter could be written. This value is close to the calculated minimum diameter of re

  2. Sequential assembly of phototunable ferromagnetic ultrathin films with perpendicular magnetic anisotropy.

    Science.gov (United States)

    Suda, Masayuki; Einaga, Yasuaki

    2009-01-01

    Getting organized: Assemblies of ferromagnetic FePt nanoparticles were generated with large perpendicular magnetic anisotropy by a magnetic-field-assisted layer-by-layer method, and subsequently layer-by-layer films consisting of L1(0)-FePt nanoparticles and organic polymers were prepared. These films are phototunable when photochromic molecules are used as polymer layers.

  3. Copper dusting effects on perpendicular magnetic anisotropy in Pt/Co/Pt tri-layers

    Science.gov (United States)

    Parakkat, Vineeth Mohanan; Ganesh, K. R.; Anil Kumar, P. S.

    2016-05-01

    The effect of Cu dusting on perpendicular magnetic anisotropy of sputter grown Pt/Co/Pt stack in which the Cu layer is in proximity with that of Co is investigated in this work. We used magneto optic Kerr effect microscopy measurements to study the variation in the reversal mechanisms in films with Co thicknesses below 0.8nm by systematically varying their perpendicular magnetic anisotropy using controlled Cu dusting. Cu dusting was done separately above and below the cobalt layer in order to understand the role of bottom and top Pt layers in magnetization reversal mechanisms of sputtered Pt/Co/Pt stack. The introduction of even 0.3nm thick Cu layer below the cobalt layer drastically affected the perpendicular magnetic anisotropy as evident from the nucleation behavior. On the contrary, even a 4nm thick top Cu layer had little effect on the reversal mechanism. These observations along with magnetization data was used to estimate the role of top and bottom Pt in the origin of perpendicular magnetic anisotropy as well as magnetization switching mechanism in Pt/Co/Pt thin films. Also, with an increase in the bottom Cu dusting from 0.2 to 0.4nm there was an increase in the number of nucleation sites resulting in the transformation of domain wall patterns from a smooth interface type to a finger like one and finally to maze type.

  4. Phenomenology of current-skyrmion interactions in thin films with perpendicular magnetic anisotropy

    NARCIS (Netherlands)

    Knoester, M. E.; Sinova, Jairo; Duine, R. A.

    2014-01-01

    We study skyrmions in magnetic thin films with structural inversion asymmetry perpendicular to the film plane. We construct a phenomenological model that describes the interaction between the motion of skyrmions and electric currents to lowest order in spin-orbit coupling. Based on this model, we es

  5. Study of nanocrystalline thin cobalt films with perpendicular magnetic anisotropy obtained by thermal evaporation

    Science.gov (United States)

    Kozłowski, Witold; Balcerski, Józef; Szmaja, Witold

    2017-02-01

    We have performed a detailed investigation of the morphological and magnetic domain structures of nanocrystalline thin cobalt films with perpendicular magnetic anisotropy. The films were thermally evaporated at an incidence angle of 0° in a vacuum of about 10-5 mbar and possessed thicknesses in the range from 60 nm to 100 nm. The films were studied by X-ray photoelectron spectroscopy (XPS), electron diffraction of transmission electron microscopy (TEM), atomic force microscopy (AFM), magnetic force microscopy (MFM) and the Fresnel mode of TEM. The films are polycrystalline and consist of very densely packed grains with sizes at the nanometer range. The grains are roundish in shape and generally exhibit no geometric alignment. The films are mainly composed of the hexagonal close-packed (HCP) phase of cobalt and possess preferential orientation of the cobalt grains with the hexagonal axis perpendicular to the film surface. 70 nm thick films and thicker have fully perpendicular magnetization, while 60 nm thick films possess clearly dominating perpendicular magnetization component. The magnetic domain structure is in the form of stripe domains forming a maze pattern. When the film thickness increases from 60 nm to 100 nm, the average grain size increases from 28.9 nm to 31.5 nm and the average domain width increases from 79.4 nm to 98.7 nm.

  6. Algebra of 2D periodic operators with local and perpendicular defects

    DEFF Research Database (Denmark)

    2016-01-01

    We show that 2D periodic operators with local and perpendicular defects form an algebra. We provide an algorithm for finding spectrum for such operators. While the continuous spectral components can be computed by simple algebraic operations on some matrix-valued functions and a few number...

  7. Time-Dependence effect in alumite recording media with perpendicular anisotropy

    NARCIS (Netherlands)

    Kim, Phan Le; Lodder, Cock

    1999-01-01

    In this paper, we will present a study of the time-dependence effect in alumite perpendicular media at different thicknesses. Important parameters of the time-dependence effect such as magnetic viscosity and activation volume are investigated. Viscosity as a function of applied field (viscosity cur

  8. 钝顶螺旋藻藻蓝蛋白的稳定性试验研究%STABILITY OF PHYCOCYANIN IN SPIRULINA PLATENSIS

    Institute of Scientific and Technical Information of China (English)

    张厚森; 马海乐

    2005-01-01

    用冻融的方法制备钝顶螺旋藻(Spirulina platensis)藻蓝蛋白并对纯化后的藻蓝蛋白稳定性进行了初步研究.提取后的粗提液经羟基磷灰石柱层析纯化后其纯度(A621/A280)达3.1.温度、酸碱度、乙醇对藻蓝蛋白稳定性有较大影响;NaCl、苯甲酸钠、柠檬酸等食品添加剂对其稳定性影响较小.

  9. Perpendicular Diffusion of Solar Energetic Particles: Model Results and Implications for Electrons

    Science.gov (United States)

    Strauss, R. Du Toit; Dresing, Nina; Engelbrecht, N. Eugene

    2017-03-01

    The processes responsible for the effective longitudinal transport of solar energetic particles (SEPs) are still not completely understood. We address this issue by simulating SEP electron propagation using a spatially 2D transport model that includes perpendicular diffusion. By implementing, as far as possible, the most reasonable estimates of the transport (diffusion) coefficients, we compare our results, in a qualitative manner, to recent observations at energies of 55–105 keV, focusing on the longitudinal distribution of the peak intensity, the maximum anisotropy, and the onset time. By using transport coefficients that are derived from first principles, we limit the number of free parameters in the model to (i) the probability of SEPs following diffusing magnetic field lines, quantified by a\\in [0,1], and (ii) the broadness of the Gaussian injection function. It is found that the model solutions are extremely sensitive to the magnitude of the perpendicular diffusion coefficient and relatively insensitive to the form of the injection function as long as a reasonable value of a = 0.2 is used. We illustrate the effects of perpendicular diffusion on the model solutions and discuss the viability of this process as a dominant mechanism by which SEPs are transported in longitude. Lastly, we try to quantity the effectiveness of perpendicular diffusion as an interplay between the magnitude of the relevant diffusion coefficient and the SEP intensity gradient driving the diffusion process. It follows that perpendicular diffusion is extremely effective early in an SEP event when large intensity gradients are present, while the effectiveness quickly decreases with time thereafter.

  10. Multiattribute Utility Theory without Expected Utility Foundations

    NARCIS (Netherlands)

    A.M. Stiggelbout; P.P. Wakker

    1995-01-01

    Methods for determining the form of utilities are needed for the implementation of utility theory in specific decisions. An important step forward was achieved when utility theorists characterized useful parametric families of utilities, and simplifying decompositions of multiattribute utilities. Th

  11. 碳酸氢铵为氮源对螺旋藻培养的影响%Effect of Ammonium Bicarbonate as Nitrogen Source on Spirulina platensis Cultivation

    Institute of Scientific and Technical Information of China (English)

    鲍亦璐; 刘明; 丛威; 卢运明; 宁正祥

    2012-01-01

    以碳酸氢铵作为氮源,研究在分批培养及流加培养条件下其对螺旋藻生长的影响。结果表明:当培养液中碳酸氢铵浓度小于5mmol/L时,螺旋藻生长正常;碳酸氢铵浓度超过5mmol/L时,螺旋藻生长受到抑制,解体死亡。采用生物量反馈补料的流加策略可以使培养液中螺旋藻生物量达到3.08g/L,产率达到0.26g/(L.d),藻体中蛋白质及叶绿素含量分别达到65.06%和13.37mg/g,结果证实了碳酸氢铵为氮源高密度培养螺旋藻的可行性。%The batch and fed-batch cultivations of Spirulina platensis were studied using ammonium bicarbonate as the nitrogen source. The results showed that Spirulinaplatensis could grow well when ammonium concentration in the medium was less than 5 mmol/L. However, when the concentration of ammonium bicarbonate was higher than 5 retool/L, cell growth was inhibited and disintegrated. The fed-batch cultivation using biomass-based feeding method could yield a dry cell concentration of 3.08 g/L, and a productivity of 0.26 g/(L· d). Moreover, the contents of protein and chlorophyll could reach up to 65.06% and 13.37 mg/g, respectively. Therefore, bicarbonate ammonium is a suitable nitrogen source for high cell density culture of Spirulina platensis.

  12. Comparison of Spirulina platensis microalgae and commercial activated carbon as adsorbents for the removal of Reactive Red 120 dye from aqueous effluents

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Natali F. [Institute of Chemistry, Federal University of Rio Grande do Sul, UFRGS, AV. Bento Goncalves 9500, 91501-970, Porto Alegre, RS (Brazil); Lima, Eder C., E-mail: profederlima@gmail.com [Institute of Chemistry, Federal University of Rio Grande do Sul, UFRGS, AV. Bento Goncalves 9500, 91501-970, Porto Alegre, RS (Brazil); Royer, Betina; Bach, Marta V. [Institute of Chemistry, Federal University of Rio Grande do Sul, UFRGS, AV. Bento Goncalves 9500, 91501-970, Porto Alegre, RS (Brazil); Dotto, Guilherme L.; Pinto, Luiz A.A. [Unit Operation Laboratory, School of Chemistry and Food, Federal University of Rio Grande, FURG, R. Engenheiro Alfredo Huch 475, 96201-900, Rio Grande, RS (Brazil); Calvete, Tatiana [Universitary Center La Salle (UNILASALLE), Av. Victor Barreto 2288, 92010-000, Canoas, RS (Brazil)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Spirulina platensis (SP) and activated carbon (AC) were used to remove RR-120 dye. Black-Right-Pointing-Pointer The maximum adsorption capacities were found at pH 2 and 298 K. Black-Right-Pointing-Pointer The values were 482.2 and 267.2 mg g{sup -1} for SP and AC, respectively. Black-Right-Pointing-Pointer Adsorption was exothermic, spontaneous and favorable. Black-Right-Pointing-Pointer SP and AC were effective to treat a simulated dye-house effluent. - Abstract: Spirulina platensis microalgae (SP) and commercial activated carbon (AC) were compared as adsorbents to remove Reactive Red 120 (RR-120) textile dye from aqueous effluents. The batch adsorption system was evaluated in relation to the initial pH, contact time, initial dye concentration and temperature. An alternative kinetic model (general order kinetic model) was compared with the traditional pseudo-first order and pseudo-second order kinetic models. The equilibrium data were fitted to the Langmuir, Freundlich and Liu isotherm models, and the thermodynamic parameters were also estimated. Finally, the adsorbents were employed to treat a simulated dye-house effluent. The general order kinetic model was more appropriate to explain RR-120 adsorption by SP and AC. The equilibrium data were best fitted to the Liu isotherm model. The maximum adsorption capacities of RR-120 dye were found at pH 2 and 298 K, and the values were 482.2 and 267.2 mg g{sup -1} for the SP and AC adsorbents, respectively. The thermodynamic study showed that the adsorption was exothermic, spontaneous and favourable. The SP and AC adsorbents presented good performance for the treatment of simulated industrial textile effluents, removing 94.4-99.0% and 93.6-97.7%, respectively, of the dye mixtures containing high saline concentrations.

  13. Spectral kinetic modeling and long-term behavior assessment of Arthrospira platensis growth in photobioreactor under red (620 nm) light illumination.

    Science.gov (United States)

    Farges, Bérangère; Laroche, Céline; Cornet, Jean-François; Dussap, Claude-Gilles

    2009-01-01

    The ability to cultivate the cyanobacterium Arhtrospira platensis in artificially lightened photobioreactors using high energetic efficiency (quasi-monochromatic) red LED was investigated. To reach the same maximal productivities as with the polychromatic lightening control conditions (red + blue, P/2e(-) = 1.275), the need to work with an optimal range of wavelength around 620 nm was first established on batch and continuous cultures. The long-term physiological and kinetic behavior was then verified in a continuous photobioreactor illuminated only with red (620 nm) LED, showing that the maximum productivities can be maintained over 30 residence times with only minor changes in the pigment content of the cells corresponding to a well-known adaptation mechanism of the photosystems, but without any effect on growth and stoichiometry. For both poly and monochromatic incident light inputs, a predictive spectral knowledge model was proposed and validated for the first time, allowing the calculation of the kinetics and stoichiometry observed in any photobioreactor cultivating A. platensis, or other cyanobacteria if the parameters were updated. It is shown that the photon flux (with a specified wavelength) must be used instead of light energy flux as a relevant control variable for the growth. The experimental and theoretical results obtained in this study demonstrate that it is possible to save the energy consumed by the lightening device of photobioreactors using red LED, the spectral range of which is defined according to the action spectrum of photosynthesis. This appears to be crucial information for applications in which the energy must be rationalized, as it is the case for life support systems in closed environments like a permanent spatial base or a submarine.

  14. Effects of Spirulina platensis supplementation on lipid profile in HIV-infected antiretroviral naïve patients in Yaounde-Cameroon: a randomized trial study.

    Science.gov (United States)

    Ngo-Matip, Marthe-Elise; Pieme, Constant Anatole; Azabji-Kenfack, Marcel; Biapa, Prosper Cabral Nya; Germaine, Nkenfack; Heike, Englert; Moukette, Bruno Moukette; Emmanuel, Korosky; Philippe, Stefanini; Mbofung, Carl Moses; Ngogang, Jeanne Yonkeu

    2014-12-13

    Cardiovascular diseases (CVD) and metabolic alterations are among the majors public health concern that have been reported in people living with HIV infections. Factors contributing to cardio metabolic syndrome in HIV include body fat distribution, dyslipidemia, insulin resistance, cardiovascular dysfunction and inflammation. The aim of the study was to determine the effect of Spirulina platensis (Cyanobacteriaceae) supplementation versus local diet on lipid profile in HIV-infected antiretroviral-naive patients. A prospective single-blind, randomized, multicentre study was conducted from February 2010 to December 2012. A total of 320 HIV antiretroviral-naïve patients were screened and 169 were recruited in this study. Patients were randomized and received either Spirulina supplementation combined with local diet (n=82) or local diet only (n=87). Age, weight, body mass index (BMI), lipid profile, CD4 count, and local food intake variables were assessed on three separate occasions (three, six and twelve months). An average age of the patients was 35.6±9 years. The majority of participants were female 67.1%. Regarding the lipid profile, there is a significant increase in HDL-cholesterol and a significant decrease in total cholesterol, LDL-cholesterol and triglycerides in the group of patients who consumed Spirulina platensis. A change in the atherogenic index defined by the ratio CT/HDL-C substitutable by LDL-C/HDL-C and the TC/HDL decreased significantly from 10.83 at baseline to 2.22 after 12 months (p=0.21 and pSpirulina. Nutritional supplementation with Spirulina combined with a quantitative and qualitative balanced diet for at least six months can retard an exposition to lipid abnormalities in HIV-infected antiretroviral-naive patients. Further studies are recommended on a large group of people not infected with HIV and exposed to cardiovascular risk factors.

  15. The Influence of Spirulina platensis Filtrates on Caco-2 Proliferative Activity and Expression of Apoptosis-Related microRNAs and mRNA.

    Science.gov (United States)

    Śmieszek, Agnieszka; Giezek, Ewa; Chrapiec, Martyna; Murat, Martyna; Mucha, Aleksandra; Michalak, Izabela; Marycz, Krzysztof

    2017-03-07

    Spirulina platensis (SP) is a blue-green microalga that has recently raised attention not only as a nutritional component, but also as a source of bioactivities that have therapeutic effects and may find application in medicine, including cancer treatment. In the present study we determined the cytotoxic effect of S. platensis filtrates (SPF) on human colon cancer cell line Caco-2. Three concentrations of SPF were tested-1.25%, 2.5%, and 5% (v/v). We have found that the highest concentration of SPF exerts the strongest anti-proliferative and pro-apoptotic effect on Caco-2 cultures. The SPF negatively affected the morphology of Caco-2 causing colony shrinking and significant inhibition of metabolic and proliferative activity of cells. The wound-healing assay showed that the SPF impaired migratory capabilities of Caco-2. This observation was consistent with lowered mRNA levels for metalloproteinases. Furthermore, SPF decreased the transcript level of pro-survival genes (cyclin D1, surviving, and c-Myc) and reduced the autocrine secretion of Wnt-10b. The cytotoxic effect of SPF involved the modulation of the Bax and Bcl-2 ratio and a decrease of mitochondrial activity, and was related with increased levels of intracellular reactive oxygen species (ROS) and nitric oxide (NO). Moreover, the SPF also caused an increased number of cells in the apoptotic sub-G0 phase and up-regulated expression of mir-145, simultaneously decreasing expression of mir-17 and 146. Obtained results indicate that SPF can be considered as an agent with anti-cancer properties that may be used for colon cancer prevention and treatment.

  16. Optimization of ultrasonic extraction of chlorophylls from Spirulina platensis by response surface methodology%响应面法优化螺旋藻中叶绿素的超声提取工艺

    Institute of Scientific and Technical Information of China (English)

    童洋; 肖国民; 潘晓梅

    2009-01-01

    @@ 引言 螺旋藻(Spirulina platensis)是一种丝状原核藻类,富含藻蓝蛋白、叶绿素、胡萝卜素及不饱各脂肪酸等多种生物活性成分.%Chlorophylls were extracted by using ultrasonic from Spirulina platensis. Single factor examination and response surface analysis experiments were adopted to investigate the effects of extraction time, extraction solvent, solvent concentration, ratio of liquid to solid and extraction grade. The results showed that the optimal process parameters for this method were: extraction time of 56. 5 min, ethanol concentration of 48. 3% (vol) of ethanol/acetone solvent, and ratio of liquid to solid of 7. 9 ml·g~(-1). The optimized chlorophylls extraction yield was 1. 28%. The comparison experimental results indicated that the yield of chlorophylls by ultrasonic extraction was higher than that obtained from conventional solvent extraction.

  17. Preparation and Cr(Ⅵ) biosorption properties of magnetic biosorbents of Spirulina platensis%钝顶螺旋藻磁性生物吸附剂的制备及对铬(Ⅵ)的吸附性能

    Institute of Scientific and Technical Information of China (English)

    廖鹏飞; 张武昌; 穆巍巍; 吕欢欢; 黄玉琴; 夏金兰; 葛刚

    2011-01-01

    The magnetic biosorbents of Spirulina platensis were prepared via enwrapping of magnetic Fe3C>4 nanoparticles and Spirulina platensis by alginate. The biosorption of Cr(VI) on the magnetic biosorbents of Spirulina platensis was investigated in different cases including the influence of pH, temperature and the absorption kinetics as well as biosorption equation. The results indicate that the optimum absorptive condition for Cr(VI) is as follows: pH of 1.5, the adsorption temperature of 40 °C, and the adsorptive capacity is 96.5% of the saturated adsorptive capacity after the adsorptive time of 120 min. With the increase of the initial concentration of Cr(VI), the absorptive capacity of the magnetic biosorbents of Spirulina platensis increases, while absorptive efficiency of magnetic biosorbents of Spirulina platensis decreases. The absorption properties of magnetic biosorbents of Spirulina platensis are very different from that of alginate, indicating that the adsorption of the magnetic biosorbents is basically due to the adsorption of the Spirulina platensis cells. Biosorption properties of magnetic biosorbents of Spirulina platensis on Cr(VI) can be described well by Langmuir and Freundlich isotherm equations. Furthermore, the magnetic biosorbents can be very facilely recycled under the influence of the external magnetic field, thus simplifying the further processing of adsorption of heavy metal ion.%以钝顶螺旋藻和磁性纳米粒子四氧化三铁为材料,采用海藻酸钙进行包埋制备出钝顶螺旋藻磁性生物吸附剂,从pH、温度、吸附动力学等方面研究钝顶螺旋藻磁性生物吸附剂对Cr(Ⅵ)的吸附性能.研究结果表明:当pH为1.5,温度为40℃时,吸附效果最好,时间在120 min时吸附容量达到饱和吸附量的96.5%;随Cr(Ⅵ)离子初始浓度的增加,吸附量增加,吸附效率减小.且与海藻酸钙吸附行为显著不同,说明主要是由钝项螺旋藻对Cr(Ⅵ)离子吸附作

  18. Spirulina platensis Improves Mitochondrial Function Impaired by Elevated Oxidative Stress in Adipose-Derived Mesenchymal Stromal Cells (ASCs) and Intestinal Epithelial Cells (IECs), and Enhances Insulin Sensitivity in Equine Metabolic Syndrome (EMS) Horses

    Science.gov (United States)

    Nawrocka, Daria; Kornicka, Katarzyna; Śmieszek, Agnieszka

    2017-01-01

    Equine Metabolic Syndrome (EMS) is a steadily growing life-threatening endocrine disorder linked to insulin resistance, oxidative stress, and systemic inflammation. Inflammatory microenvironment of adipose tissue constitutes the direct tissue milieu for various cell populations, including adipose-derived mesenchymal stromal cells (ASCs), widely considered as a potential therapeutic cell source in the course of the treatment of metabolic disorders. Moreover, elevated oxidative stress induces inflammation in intestinal epithelial cells (IECs)—the first-line cells exposed to dietary compounds. In the conducted research, we showed that in vitro application of Spirulina platensis contributes to the restoration of ASCs’ and IECs’ morphology and function through the reduction of cellular oxidative stress and inflammation. Enhanced viability, suppressed senescence, and improved proliferation of ASCs and IECs isolated from metabolic syndrome-affected individuals were evident following exposition to Spirulina. A protective effect of the investigated extract against mitochondrial dysfunction and degeneration was also observed. Moreover, our data demonstrate that Spirulina extract effectively suppressed LPS-induced inflammatory responses in macrophages. In vivo studies showed that horses fed with a diet based on Spirulina platensis supplementation lost weight and their insulin sensitivity improved. Thus, our results indicate the engagement of Spirulina platensis nourishing as an interesting alternative approach for supporting the conventional treatment of equine metabolic syndrome. PMID:28771165

  19. Electric-field assisted switching of magnetization in perpendicularly magnetized (Ga,Mn)As films at high temperatures

    Science.gov (United States)

    Wang, Hailong; Ma, Jialin; Yu, Xueze; Yu, Zhifeng; Zhao, Jianhua

    2017-01-01

    The electric-field effects on the magnetism in perpendicularly magnetized (Ga,Mn)As films at high temperatures have been investigated. An electric-field as high as 0.6 V nm-1 is applied by utilizing a solid-state dielectric Al2O3 film as a gate insulator. The coercive field, saturation magnetization and magnetic anisotropy have been clearly changed by the gate electric-field, which are detected via the anomalous Hall effect. In terms of the Curie temperature, a variation of about 3 K is observed as determined by the temperature derivative of the sheet resistance. In addition, electrical switching of the magnetization assisted by a fixed external magnetic field at 120 K is demonstrated, employing the gate-controlled coercive field. The above experimental results have been attributed to the gate voltage modulation of the hole density in (Ga,Mn)As films, since the ferromagnetism in (Ga,Mn)As is carrier-mediated. The limited modulation magnitude of magnetism is found to result from the strong charge screening effect introduced by the high hole concentration up to 1.10  ×  1021 cm-3, while the variation of the hole density is only about 1.16  ×  1020 cm-3.

  20. Influence of thickness variation on perpendicular magnetic anisotropy features of the [co/pt]n multilayer frame.

    Science.gov (United States)

    Lee, Ja Bin; An, Gwang Guk; Yang, Seung Mo; Hong, Jin Pyo

    2014-11-01

    We report the structural and magnetic properties of a [Co/Pt] multilayer matrix as a function of Pt thickness. Increasing Pt thickness allows for the formation of a well-aligned fcc (111) CoPt3 structure in a [Co/Pt]n multilayer geometry, where the clear appearance of main (111) peak of CoPt3 measured using the X-ray diffraction patterns was confirmed. High-resolution transmission electron microscopy images, along with the corresponding fast Fourier transform patterns displayed the ordered structure with clear 6-fold symmetric diffraction spots. The c/a lattice constant ratio of 0.949 was calculated by utilizing the XRD and, demonstrating the presence of a well-aligned CoPt3 structure. The Pt thickness-dependent saturation magnetization (M(s)) values for the in- and out-of-plane M-H hysteresis loops obtained by vibrating sample magnetometer measurements showed distinctly opposite trends. The increase in the out-of-plane M(s) value with increasing Pt thickness seems to originate from the enhanced perpendicular orbital moment of the proper CoPt3 structure.

  1. Influence of thermal agitation on the electric field induced precessional magnetization reversal with perpendicular easy axis

    Directory of Open Access Journals (Sweden)

    Hongguang Cheng

    2013-12-01

    Full Text Available We investigated the influence of thermal agitation on the electric field induced precessional magnetization switching probability with perpendicular easy axis by solving the Fokker-Planck equation numerically with finite difference method. The calculated results show that the thermal agitation during the reversal process crucially influences the switching probability. The switching probability can be achieved is only determined by the thermal stability factor Δ of the free layer, it is independent on the device dimension, which is important for the high density device application. Ultra-low error rate down to the order of 10−9 can be achieved for the device of thermal stability factor Δ of 40. Low damping factor α material should be used for the free layer for high reliability device applications. These results exhibit potential of electric field induced precessional magnetization switching with perpendicular easy axis for ultra-low power, high speed and high density magnetic random access memory (MRAM applications.

  2. Tetragonal Heusler-Like Mn-Ga Alloys Based Perpendicular Magnetic Tunnel Junctions

    Science.gov (United States)

    Ma, Qinli; Sugihara, Atsushi; Suzuki, Kazuya; Zhang, Xianmin; Miyazaki, Terunobu; Mizukami, Shigemi

    2014-10-01

    Films of the Mn-based tetragonal Heusler-like alloys, such as Mn-Ga, exhibit a large perpendicular magnetic anisotropy (PMA), small damping constant, small saturation magnetization and large spin polarizations. These properties are attractive for the application to the next generation high density spin-transfer-torque (STT) magnetic random access memory (STT-MRAM). We reviewed the structure, magnetic properties and Gilbert damping of the alloy films with large PMA, and the current status of research on tunnel magnetoresistance (TMR) in perpendicular magnetic tunnel junctions (p-MTJs) based on Mn-based tetragonal Heusler-like alloy electrode, and also discuss the issues for the application of those to STT-MRAM.

  3. Influence of thermal agitation on the electric field induced precessional magnetization reversal with perpendicular easy axis

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hongguang, E-mail: chenghg7932@gmail.com; Deng, Ning [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China)

    2013-12-15

    We investigated the influence of thermal agitation on the electric field induced precessional magnetization switching probability with perpendicular easy axis by solving the Fokker-Planck equation numerically with finite difference method. The calculated results show that the thermal agitation during the reversal process crucially influences the switching probability. The switching probability can be achieved is only determined by the thermal stability factor Δ of the free layer, it is independent on the device dimension, which is important for the high density device application. Ultra-low error rate down to the order of 10{sup −9} can be achieved for the device of thermal stability factor Δ of 40. Low damping factor α material should be used for the free layer for high reliability device applications. These results exhibit potential of electric field induced precessional magnetization switching with perpendicular easy axis for ultra-low power, high speed and high density magnetic random access memory (MRAM) applications.

  4. MnxGa1-x nanodots with high coercivity and perpendicular magnetic anisotropy

    Science.gov (United States)

    Karel, J.; Casoli, F.; Lupo, P.; Celegato, F.; Sahoo, R.; Ernst, B.; Tiberto, P.; Albertini, F.; Felser, C.

    2016-11-01

    A MnxGa1-x (x = 0.70) epitaxial thin film with perpendicular magnetic anisotropy and a large coercivity (μ0Hc = 1 T) was patterned into nanodots using a combined self-assembly nanolithography and plasma etching procedure. Nanostructuring is achieved by self-assembly of polystyrene nanospheres acting as a mask on the magnetic film. This procedure allows easy patterning of a large area although introduced some chemical disorder, which resulted in a soft magnetic component in the magnetic hysteresis loops. However, chemical order was recovered after vacuum annealing at low temperature. The resulting nanodots retain the properties of the original film, i.e. magnetization oriented perpendicular to the particle and large coercivity. Our results suggest this lithography procedure could be a promising direction for nanostructuring tetragonal Heusler alloys.

  5. Perpendicular spin injection and polarization features in InAs quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D. [Lehrstuhl fuer Angewandte Festkoerperphysik, Ruhr-Universitaet Bochum (Germany); Soldat, Henning; Li, Mingyuan; Gerhardt, Nils C.; Hofmann, Martin [Lehrstuhl fuer Photonik und Terahertztechnologie, Ruhr-Universitaet Bochum (Germany); Stromberg, Frank; Warland, Anne; Wende, Heiko; Keune, Werner [Fachbereich Physik, Center for Nanointegration Duisburg-Essen, Universitaet Duisburg-Essen (Germany); Ebbing, Astrid [Lehrstuhl fuer Angewandte Festkoerperphysik, Ruhr-Universitaet Bochum (Germany); Experimentalphysik IV - Festkoerperphysik, Ruhr-Universitaet Bochum (Germany); Petracic, Oleg [Experimentalphysik IV - Festkoerperphysik, Ruhr-Universitaet Bochum (Germany)

    2011-07-01

    Self assembled InAs quantum dots (QDs) are zero dimensional multilevel systems with long spin relaxation times and thus offer great potential for spin optoelectronic research and applications. Electrically injected spin polarization is efficiently transferred into circularly polarized photons if the injected spin is oriented perpendicularly to the growth plane. The optical polarization from an ensemble of QDs in a spin-LED is strongly magnetic field dependent due to the orbital character of the transitions of excited carriers. An unambiguous separation of spin injection and Zeeman shift is obtained by investigating the magnetic field dependence of the circular polarisation of the spin-LED emission. Here we present and analyze perpendicular spin injection from Fe/Tb magnetic injectors at room temperature and in remanence. Polarization features of excited transitions are discussed.

  6. Tuning of the nucleation field in nanowires with perpendicular magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Kimling, Judith; Gerhardt, Theo; Kobs, Andre; Vogel, Andreas; Peter Oepen, Hans; Merkt, Ulrich; Meier, Guido [Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung Hamburg, Universitaet Hamburg, Jungiusstr. 11, 20355 Hamburg (Germany); Wintz, Sebastian [Institut fuer Ionenstrahlphysik und Materialforschung, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden (Germany); Im, Mi-Young; Fischer, Peter [Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2013-04-28

    We report on domain nucleation in nanowires consisting of Co/Pt multilayers with perpendicular magnetic anisotropy that are patterned by electron-beam lithography, sputter deposition, and lift-off processing. It is found that the nucleation field can be tuned by changing the geometry of the wire ends. A reduction of the nucleation field by up to 60% is achieved when the wire ends are designed as tips. This contrasts with the behavior of wires with in-plane anisotropy where the nucleation field increases when triangular-pointed ends are used. In order to clarify the origin of the reduction of the nucleation field, micromagnetic simulations are employed. The effect cannot be explained by the lateral geometrical variation but is attributable to a local reduction of the perpendicular anisotropy caused by shadowing effects due to the resist mask during sputter deposition of the multilayer.

  7. Band gap engineering of silicene zigzag nanoribbons with perpendicular electric fields: a theoretical study.

    Science.gov (United States)

    Liang, Yunye; Wang, Vei; Mizuseki, Hiroshi; Kawazoe, Yoshiyuki

    2012-11-14

    The electronic properties of silicene zigzag nanoribbons with the presence of perpendicular fields are studied by using first-principles calculations and the generalized nearest neighboring approximation method. In contrast to the planar graphene, in silicene the Si atoms are not coplanar. As a result, by applying perpendicular fields to the two-dimensional silicene sheet, the on-site energy can be modulated and the band gap at the Dirac point is open. The buckled structure also creates a height difference between the two edges of the silicene zigzag nanoribbons. We find that the external fields can modulate the energies of spin-polarized edge states and their corresponding band gaps. Due to the polarization in the plane, the modulation effect is width dependent and becomes much more significant for narrow ribbons.

  8. Average observed properties of the Earth's quasi-perpendicular and quasi-parallel bow shock

    CERN Document Server

    Czaykowska, A; Treumann, R A; Baumjohann, W

    2000-01-01

    We present a statistical analysis of 132 dayside (LT 0700-1700) bow shock crossings of the AMPTE/IRM spacecraft. We perform a superposed epoch analysis of plasma and magnetic field parameters as well as of low frequency magnetic power spectra some minutes upstream and downstream of the bow shock by dividing the events into categories depending on the angle between bow shock normal and interplanetary magnetic field and on the plasma-beta, i.e., the ratio of plasma to magnetic pressure. Downstream of the quasi-perpendicular low-beta (beta 1.0) crossings mirror waves are identified. However, there are also cases where the conditions for mirror modes are met downstream of the nearly perpendicular shock, but no mirror waves are observed.

  9. Micromagnetic simulation of FeCo write head in perpendicular recording hard disk drives

    Institute of Scientific and Technical Information of China (English)

    QUAN Liang; WEI Dan

    2006-01-01

    The single-pole tip (SPT) heads made of the high saturation FeCo ferromagnetic metals are crucial for the actualization of ultrahigh density perpendicular recording. The effective head field distribution in the medium is of key importance for the design of the SPT head, which would be analyzed by micromagnetic simulations in this work. Two 3D micromagnetic models of the SPT head were established to select a more appropriate method of modeling, with a magnetostatic image effect or a real soft magnetic material to model the image of the SPT head in soft under layer (SUL). The results from these two designs were tested and compared to the ideal head field calculated by the Jacobi finite element method (FEM); and the design with the real soft magnetic material as image was proved suitable for simulating the ultrahigh density perpendicular recording write head.

  10. A Perpendicular Biased 2nd Harmonic Cavity for the Fermilab Booster

    Energy Technology Data Exchange (ETDEWEB)

    Tan, C. Y.; Dey, J. [Fermilab; Madrak, R. L. [Fermilab; Pellico, W. [Fermilab; Romanov, G. [Fermilab; Sun, D. [Fermilab; Terechkine, I. [Fermilab

    2015-07-13

    A perpendicular biased 2nd harmonic cavity is currently being designed for the Fermilab Booster. Its purpose cavity is to flatten the bucket at injection and thus change the longitudinal beam distribution so that space charge effects are decreased. It can also with transition crossing. The reason for the choice of perpendicular biasing over parallel biasing is that the Q of the cavity is much higher and thus allows the accelerating voltage to be a factor of two higher than a similar parallel biased cavity. This cavity will also provide a higher accelerating voltage per meter than the present folded transmission line cavity. However, this type of cavity presents technical challenges that need to be addressed. The two major issues are cooling of the garnet material from the effects of the RF and the cavity itself from eddy current heating because of the 15 Hz bias field ramp. This paper will address the technical challenge of preventing the garnet from overheating.

  11. Strain-assisted magnetization reversal in Co/Ni multilayers with perpendicular magnetic anisotropy.

    Science.gov (United States)

    Gopman, D B; Dennis, C L; Chen, P J; Iunin, Y L; Finkel, P; Staruch, M; Shull, R D

    2016-06-14

    Multifunctional materials composed of ultrathin magnetic films with perpendicular magnetic anisotropy combined with ferroelectric substrates represent a new approach toward low power, fast, high density spintronics. Here we demonstrate Co/Ni multilayered films with tunable saturation magnetization and perpendicular anisotropy grown directly on ferroelectric PZT [Pb(Zr0.52Ti0.48)O3] substrate plates. Electric fields up to ±2 MV/m expand the PZT by 0.1% and generate at least 0.02% in-plane compression in the Co/Ni multilayered film. Modifying the strain with a voltage can reduce the coercive field by over 30%. We also demonstrate that alternating in-plane tensile and compressive strains (less than 0.01%) can be used to propagate magnetic domain walls. This ability to manipulate high anisotropy magnetic thin films could prove useful for lowering the switching energy for magnetic elements in future voltage-controlled spintronic devices.

  12. Ferromagnetic MnGaN thin films with perpendicular magnetic anisotropy for spintronics applications

    Science.gov (United States)

    Lee, Hwachol; Sukegawa, Hiroaki; Liu, Jun; Ohkubo, Tadakatsu; Kasai, Shinya; Mitani, Seiji; Hono, Kazuhiro

    2015-07-01

    Perpendicularly magnetized flat thin films of antiperovskite Mn67Ga24N9 were grown on an MgO(001) substrate by reactive sputtering using an argon/1% nitrogen gas mixture and a Mn70Ga30 target. The films showed a saturation magnetization of 80 -100 kA/m, an effective perpendicular magnetic anisotropy (PMA) energy of 0.1-0.2 MJ/m3, and a Curie temperature of 660-740 K. Upon increasing the N composition, the films transformed from ferromagnetic to antiferromagnetic as expected in the stoichiometric Mn3GaN phase. Point contact Andreev reflection spectroscopy revealed that the ferromagnetic MnGaN has a current spin polarization of 57%, which is comparable to D022-MnGa. These findings suggest that MnGaN is a promising PMA layer for future spintronics devices.

  13. Angular dependence of demagnetization processes in Fe-FePt perpendicular exchange-spring bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Solzi, M. [Dipartimento di Fisica, Universita di Parma and CNISM, V.le G.P. Usberti 7/A, 43100 Parma (Italy)]. E-mail: solzi@fis.unipr.it; Pernechele, C. [Dipartimento di Fisica, Universita di Parma and CNISM, V.le G.P. Usberti 7/A, 43100 Parma (Italy); Pellicelli, R. [Dipartimento di Fisica, Universita di Parma and CNISM, V.le G.P. Usberti 7/A, 43100 Parma (Italy); Ghidini, M. [Dipartimento di Fisica, Universita di Parma and CNISM, V.le G.P. Usberti 7/A, 43100 Parma (Italy); Albertini, F. [IMEM-CNR, Parco Area delle Scienze 37/A, 43010 Parma (Italy); Casoli, F. [IMEM-CNR, Parco Area delle Scienze 37/A, 43010 Parma (Italy)

    2007-09-15

    The angular dependence of hysteresis loops of exchange-spring (ES) bilayers constituted by a Fe layer as the soft phase and a hard layer of L1{sub 0} Fe{sub 53}Pt{sub 47} is presented. FePt thin films of nominal thickness 10 nm have been prepared by RF sputtering on MgO (1 0 0) substrates in order to achieve the epitaxial growth with the c-axis perpendicular to the film plane. The Fe soft layers have been deposited at RT with various thicknesses (from 2 to 10 nm). The angular dependence of the bilayers' magnetic properties is studied by SQUID magnetometry varying the angle between the easy axis of the hard phase and the direction of the applied field from 0 to {pi}/2. The magnetic behavior at different angles is analyzed by a one-dimensional micromagnetic model specifically extended to the case of perpendicular magnetic anisotropy (PMA)

  14. Perpendicular magnetic anisotropy and magnetic domain structure of unpatterned and patterned Co/Pt multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J.C.A. E-mail: jcahuang@mail.ncku.edu.tw; Wu, L.C.; Chen, M.M.; Wu, T.H.; Wu, J.C.; Huang, Y.W.; Lee, C.H.; Fu, C.M

    2000-02-01

    Perpendicular magnetic anisotropy and magnetic domain structure were studied in epitaxial [Co(t{sub Co})/Pt(10 A)]{sub 30} (t{sub Co}=2, 2.5, 3, 4, 5 and 10 A) multilayers prepared on Al{sub 2}O{sub 3}(1 1 -2 0) substrate via Mo or Pt seed layer. The best perpendicular magnetic effect occurred for t{sub Co}{approx}3 A. At remnant state the domain size tends to increase as t{sub Co} decreases, and the domain structure depends strongly on the seed layer. For [Co(3 A)/Pt(10 A)]{sub 30} multilayers grown on gold grid made hole arrays, the polar coercivity inside the holes is different from those on the gold land and unpatterned area.

  15. High tunneling magnetoresistance ratio in perpendicular magnetic tunnel junctions using Fe-based Heusler alloys

    Science.gov (United States)

    Wang, Yu-Pu; Lim, Sze-Ter; Han, Gu-Chang; Teo, Kie-Leong

    2015-12-01

    Heulser alloys Fe2Cr1-xCoxSi (FCCS) with different Co compositions x have been predicted to have high spin polarization. High perpendicular magnetic anisotropy (PMA) has been observed in ultra-thin FCCS films with magnetic anisotropy energy density up to 2.3 × 106 erg/cm3. The perpendicular magnetic tunnel junctions (p-MTJs) using FCCS films with different Co compositions x as the bottom electrode have been fabricated and the post-annealing effects have been investigated in details. An attractive tunneling magnetoresistance ratio as high as 51.3% is achieved for p-MTJs using Fe2CrSi (FCS) as the bottom electrode. The thermal stability Δ can be as high as 70 for 40 nm dimension devices using FCS, which is high enough to endure a retention time of over 10 years. Therefore, Heusler alloy FCS is a promising PMA candidate for p-MTJ application.

  16. Transport through a strongly coupled graphene quantum dot in perpendicular magnetic field

    Directory of Open Access Journals (Sweden)

    Güttinger Johannes

    2011-01-01

    Full Text Available Abstract We present transport measurements on a strongly coupled graphene quantum dot in a perpendicular magnetic field. The device consists of an etched single-layer graphene flake with two narrow constrictions separating a 140 nm diameter island from source and drain graphene contacts. Lateral graphene gates are used to electrostatically tune the device. Measurements of Coulomb resonances, including constriction resonances and Coulomb diamonds prove the functionality of the graphene quantum dot with a charging energy of approximately 4.5 meV. We show the evolution of Coulomb resonances as a function of perpendicular magnetic field, which provides indications of the formation of the graphene specific 0th Landau level. Finally, we demonstrate that the complex pattern superimposing the quantum dot energy spectra is due to the formation of additional localized states with increasing magnetic field.

  17. High-resolution in-source laser spectroscopy in perpendicular geometry

    Energy Technology Data Exchange (ETDEWEB)

    Heinke, R., E-mail: reinhard.heinke@uni-mainz.de; Kron, T. [Universität Mainz, Institut für Physik (Germany); Raeder, S. [Helmholtz-Institut Mainz (Germany); Reich, T.; Schönberg, P. [Universität Mainz, Institut für Kernchemie (Germany); Trümper, M.; Weichhold, C.; Wendt, K. [Universität Mainz, Institut für Physik (Germany)

    2017-11-15

    Operation of the novel laser ion source unit LIST (Laser Ion Source and Trap), operating at the on-line radioactive ion beam facility ISOLDE at CERN allowed for the production of ultra-pure beams of exotic isotopes far-off stability as well as direct isobar-free laser spectroscopy, giving access to the study of atomic and nuclear properties of so far inaccessible nuclides. We present a specific upgrade and adaption of the LIST targeted for high resolution spectroscopy with a Doppler-reduced perpendicular atom - laser beam geometry. With this PI-LIST (Perpendicularly Illuminated Laser Ion Source and Trap) setup, experimental linewidths below 100 MHz could be demonstrated in optical laser spectroscopy off-line, applying a pulsed injection-locked high repetition rate Ti:sapphire laser. A dual repeller configuration ensured highest suppression of isobaric interferences and almost background-free measurements on small samples in the order of 10{sup 11} atoms.

  18. Very strong antiferromagnetic interlayer exchange coupling with iridium spacer layer for perpendicular magnetic tunnel junctions

    Science.gov (United States)

    Yakushiji, Kay; Sugihara, Atsushi; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji

    2017-02-01

    We systematically studied the interlayer exchange coupling (IEC) in a perpendicular synthetic antiferromagnetically coupled structure having an Ir spacer layer for perpendicular magnetic tunnel junctions (p-MTJs). We found a broader peak in IEC energy density (Jex) versus spacer thickness (tIr) compared with the case of using a Ru spacer. The highest IEC energy density was 2.6 erg/cm2 at a tIr of about 5 nm. The p-MTJ nanopillars had a high magnetoresistance ratio (131%) as well as a high spin-transfer torque (STT) switching efficiency (about 2). An Ir spacer can be used to make a stable reference layer for STT magnetoresistive random access memory.

  19. Three-terminal magnetic tunneling junction device with perpendicular anisotropy CoFeB sensing layer

    Energy Technology Data Exchange (ETDEWEB)

    Honjo, H., E-mail: hr-honjou@aist.go.jp; Nebashi, R.; Tokutome, K.; Miura, S.; Sakimura, N.; Sugibayashi, T. [Green Platform Research Laboratories, NEC Corporation, Tsukuba (Japan); Fukami, S.; Kinoshita, K.; Murahata, M.; Kasai, N. [Center for Spintronics Integrated Systems, Tohoku University, Sendai (Japan); Ishihara, K. [Smart Energy Research Laboratories, NEC Corporation, Tsukuba (Japan); Ohno, H. [Center for Spintronics Integrated Systems, Tohoku University, Sendai (Japan); Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai (Japan); WPI Advanced Institute for Materials Research, Tohoku University, Sendai (Japan)

    2014-05-07

    We demonstrated read and write characteristics of a three terminal memory device with a perpendicular anisotropy-free layer of a strip of [Co/Ni] and a low-switching perpendicular-anisotropy CoFeB/MgO sensing layer. This new design of the cell results in a small cell area. The switching magnetic field of the sensing layer can be decreased by changing sputtering gas for the Ta-cap from Ar to Kr. An electron energy-loss spectroscopy analysis of the cross-section of the magnetic tunneling junction (MTJ) revealed that the boron content in CoFeB with a Kr-sputtered Ta-cap was smaller than that with an Ar-sputtered one. A change in resistance for the MTJ was observed that corresponded to the magnetic switching of the Co/Ni wire and its magnetoresistance ratio and critical current were 90% and 0.8 mA, respectively.

  20. Plasma effects on fast pair beams. III. Oblique electrostatic growth rates for perpendicular Maxwellian pair beams

    Energy Technology Data Exchange (ETDEWEB)

    Supsar, Markus; Schlickeiser, Reinhard, E-mail: markus.supsar@tp4.rub.de, E-mail: rsch@tp4.rub.de [Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2014-03-10

    The distant universe is opaque to γ radiation from blazars due to gamma-gamma attenuation with extragalactic background light. This process produces electron-positron pair beams that interact with the intergalactic medium and are unstable to linear instabilities, particularly the electrostatic and Weibel instabilities. The electrostatic instability grows faster and so determines the dissipation of the free energy of the beam. Here, we generalize the calculation of the electrostatic growth rate to a beam plasma system with a Maxwellian perpendicular momentum spread and allow for oblique propagation directions. We show that the growth rate for the oblique electrostatic mode has a maximum value that is even higher than for a cold beam or for one with a constant perpendicular momentum spread.