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Sample records for alimentado con microalgas

  1. Evaluación del peso de conejos para carne alimentados con diferentes ensilajes

    Directory of Open Access Journals (Sweden)

    Rigoberto Villa-Ramírez

    2016-11-01

    Full Text Available En la Granja Experimental Bengala, de la Universidad del Quindío, ubicada en el municipio de Filandia, Quindío, se evaluó la ganancia de peso en conejos tipo carne cuando son alimentados con diferentes ensilajes: pasto imperial (Axonopus scoparius, pasto imperial mezclado con botón de oro (Tithonia diversifolia (Hemsl., pasto imperial con ramio (Boehmeria nivea y pasto imperial con morera (Morus alba. Se valoraron cuatro tratamientos en cuatro grupos de cinco conejos cada uno. Los conejos alimentados con ensilaje de pasto imperial y botón de oro fueron los que obtuvieron el mayor peso (2389 g, en promedio, mientras que los alimentados con solo forrajes frescos obtuvieron un peso promedio de 2021 g. Las fuentes nutricionales que mejor responden en la alimentación de conejos son, en su orden: ensilaje de botón de oro, ensilaje de morera y ensilaje de ramio.

  2. Evaluación del peso de conejos para carne alimentados con diferentes ensilajes

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    Rigoberto Villa-Ramírez; Jaime Hurtado-Villegas

    2016-01-01

    En la Granja Experimental Bengala, de la Universidad del Quindío, ubicada en el municipio de Filandia, Quindío, se evaluó la ganancia de peso en conejos tipo carne cuando son alimentados con diferentes ensilajes: pasto imperial (Axonopus scoparius), pasto imperial mezclado con botón de oro (Tithonia diversifolia (Hemsl.), pasto imperial con ramio (Boehmeria nivea) y pasto imperial con morera (Morus alba). Se valoraron cuatro tratamientos en cuatro grupos de cinco conejos cada uno. Los conejos...

  3. Cultivo de cianobacterias para la producción de bioplasticos en un fotobioreactor tubular cerrado alimentado con digestado

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    Torrado Rufete, Carlos

    2016-01-01

    En este trabajo se determinarán las condiciones optimas de cultivo de cianobacterias para la producción de bioplasticos. Para el desarrollo del cultivo se utilizará un fotobioreactor tubular cerrado alimentado con digestado diluido con agua residual tratada

  4. Bioenergética de juveniles de langosta de quelas rojas, Cherax quadricarinatus, alimentados con dos dietas artificiales

    OpenAIRE

    Eugenio Díaz-Iglesias; Víctor Meza Castillo; Marysabel Báez-Hidalgo; Ana Denise Re-Araujo; Antonio Silva-Loera

    2012-01-01

    Se evaluó la respuesta metabólica de juveniles de langosta australiana de quelas rojas, Cherax quadricarinatus, alimentados con dos dietas artificiales (Rangen con 35% de proteína y Cherax1 con 32% de proteína de sustrato vegetal), aclimatados a la temperatura preferida de 28 ºC en un respirómetro dinámico, midiendo el consumo de oxígeno y la excreción amoniacal durante el ayuno y la alimentación, y determinándose además la mortalidad y el crecimiento. La energía consumida por los juveniles e...

  5. Productividad y eficiencia de uso de nitrógeno y energía en pollos de engorda alimentados con pasta de soya o pasta de canola

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    Sergio Gómez Rosales; María de Lourdes Angeles; Ericka Ramírez Rodríguez

    2012-01-01

    Se realizaron dos experimentos de sacrificio para evaluar el crecimiento, contenido y deposición de tejidos y retención de proteína y energía en la carne de la canal en pollos en crecimiento alimentados con pasta de canola (PCAN) en sustitución de pasta de soya (PSOY). En el Exp 1, seis pollos machos, de 43 días de edad, se sacrificaron al inicio y 36 pollos fueron asignados a tres dietas con cantidades crecientes de PCAN (0, 10 y 20 %) combinadas con dos niveles de lisina digestible (LD: 0.8...

  6. Respuesta productiva de conejos alimentados con forraje verde hidropónico de avena, como reemplazo parcial de concentrado comercial

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    Francisco Fabián Fuentes Carmona

    2011-04-01

    Full Text Available La respuesta productiva de conejos raza californiana alimentados con forraje verde hidropónico (FVH de avena como reemplazo parcial de concentrado comercial (CC, fue evaluada en condiciones de desierto en el norte de Chile. Se establecieron cinco tratamientos de alimentación, equivalentes a 0, 25, 50, 75 y 100% de reemplazo de la dieta diaria con FVH, el cual fue cosechado y utilizado directamente diez días después de la siembra. Cuarenta y cinco conejos destetados a los 31 días fueron evaluados en un diseño completamente al azar hasta alcanzar un peso de sacrificio de 2 kg de peso vivo. La calidad del FVH de avena fue considerada como buena, presentando similar valor nutritivo que el CC. Las variables evaluadas y sus respectivos rangos fueron: consumo de materia seca promedio (59.17 - 104.73 g/día, ganancia de peso vivo promedio (16.35 - 29.10 g/animal por día, conversión alimenticia promedio (3.31 - 3.93 kg MS/kg PV, tiempo de peso vivo a sacrificio (53 - 91 días, peso vivo final (1430 - 2044 g/animal, peso de la canal (1235 - 1385 g/animal y rendimiento de la canal (59.19 - 62.25%. El reemplazo de hasta 50% de la dieta base con FVH de avena no afectó significativamente (P < 0.05 el consumo de alimento, tiempo de peso vivo a sacrificio, peso vivo final y rendimiento de la canal, haciendo posible su uso como recurso forrajero alternativo en la alimentación de conejos en etapa de engorde en condiciones de desierto.

  7. Respuesta productiva de conejos alimentados con forraje verde hidropónico de avena, como reemplazo parcial de concentrado comercial

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    Poblete Pérez Cecilia Eva

    2011-06-01

    Full Text Available La respuesta productiva de conejos raza californiana alimentados con forraje verde hidropónico (FVH deavena como reemplazo parcial de concentrado comercial (CC, fue evaluada en condiciones de desiertoen el norte de Chile. Se establecieron cinco tratamientos de alimentación, equivalentes a 0, 25, 50, 75 y100% de reemplazo de la dieta diaria con FVH, el cual fue cosechado y utilizado directamente diez díasdespués de la siembra. Cuarenta y cinco conejos destetados a los 31 días fueron evaluados en un diseñocompletamente al azar hasta alcanzar un peso de sacrificio de 2 kg de peso vivo. La calidad del FVH deavena fue considerada como buena, presentando similar valor nutritivo que el CC. Las variables evaluadasy sus respectivos rangos fueron: consumo de materia seca promedio (59.17 - 104.73 g/día, gananciade peso vivo promedio (16.35 - 29.10 g/animal por día, conversión alimenticia promedio (3.31 - 3.93 kgMS/kg PV, tiempo de peso vivo a sacrificio (53 - 91 días, peso vivo final (1430 - 2044 g/animal, pesode la canal (1235 - 1385 g/animal y rendimiento de la canal (59.19 - 62.25%. El reemplazo de hasta50% de la dieta base con FVH de avena no afectó significativamente (P ≤ 0.05 el consumo de alimento,tiempo de peso vivo a sacrificio, peso vivo final y rendimiento de la canal, haciendo posible su uso comorecurso forrajero alternativo en la alimentación de conejos en etapa de engorde en condiciones de desierto.

  8. Comportamiento productivo de reproductoras porcinas alimentados con follaje fresco de Morus alba. IIndicadores reproductivos

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    Contino Yuván; Ojeda Félix ; Herrera Rafael ; Altunaga Nancy; Pérez Guadalupe.

    2008-08-01

    Full Text Available El objetivo de esta investigación consistió en evaluar el consumo, larespuesta productiva y reproductiva de cerdas mestizas al emplear elfollaje de morera fresca (hojas y tallos tiernos como sustituto parcial del concentrado comercial y su repercusión en la salud de las crías. Las investigaciones se efectuaron en el Módulo de Investigación-Producción Porcina de la EEPF ”Indio Hatuey”. Se realizó una experiencia con 10 reproductoras en diferentes estados reproductivos alimentadas a voluntad con morera fresca, para determinar el consumo; y otra evaluación con reproductoras en el último tercio de la gestación que consumían morera, a voluntad para comparar sus indicadores productivos y de salud de las crías con respecto a un grupo control que no consumió el follaje fresco. Sedeterminaron los siguientes indicadores: Cantidad de cerdos nacidos, crías vivas y muertas a las 48 horas, peso al nacimiento y a los 10 días posparto,peso total de la camada al nacimiento y a los 10 días post-parto, peso al destete, porcentaje de viabilidad y de mortalidad a las 48 horas, número de crías con diarreas a las 48 horas. Para el procesamiento se empleó el paquete estadístico SPSS versión 10.1. No hubo diferencias en los índices de consumo entre las diferentes categorías reproductivas. Se obtuvo un incremento en la cantidad de crías nacidas, crías vivas a las 48 horas, en elpeso promedio de la camada, del peso al destete así como en el porcentaje de viabilidad con una disminución en las diarreas de las crías. Los resultados demuestran la factibilidad económica de esta alternativa alimentaria

  9. Alimentación y defecación en triatominos del género Rhodnius (Hemiptera: Reduviidae) alimentados con sangre humana

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    2014-01-01

    Se estudió el comportamiento alimenticio y de defecación de Rhodnius prolixus Stal, 1859, R. robustus Larrousse, 1927, R. neivai Lent, 1953 y R. pictipes Stal, 1872 alimentados artificialmente con sangre humana en condiciones de laboratorio. La ninfa I de todas las especies no defecó en la primera media hora después de haber iniciado la ingesta. R. pictipes no se acercó a picar en el alimentador artificial aunque sí lo hizo cuando el alimento se ofreció directamente sobre el cuerpo humano. La...

  10. CULTIVO EXPERIMENTAL DEL CLADOCERO Moina sp ALIMENTADO CON Ankistrodesmus sp y Saccharomyces cereviseae

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    Martha Prieto

    2006-05-01

    Full Text Available Saccharomyces cereviseae. Materiales y métodos. Fueron realizados cultivos experimentales de la cepade cladóceros Moina sp en el laboratorio de Alimento Vivo de la Universidad de Córdoba, bajo condicionescontroladas de temperatura (22oC, pH (7.6, intensidad lumínica (2000 lux y aireación. Se emplearondos dietas de alimento como tratamiento (Ankistrodesmus y Ankistrodesmus mas Saccharomyces cereviseaeen concentración de 40 x 105 cel.ml-1 cada uno, para determinar su efecto sobre el desempeño de lapoblación. Diariamente se registró la densidad poblacional y celular. Resultados. Se obtuvieron diferenciassignificativas para el efecto de las dietas sobre el crecimiento poblacional de los cladóceros, los individuosalimentados con Ankistrodesmus sp + Saccharomyces cereviseae alcanzaron una densidad de 12.3a±0.30 org/ml-1 presentando mayor tasa instantánea de crecimiento (K 0.36 ± 0.002, el menor tiempode duplicación (td 1.94 ± 0.012 y el mayor rendimiento (r 1,1 ± 0.07 clad.ml-1.día-1. Conclusión. Loscladóceros por sus características de crecimiento en cultivo, presentan adaptación favorable a lascondiciones de manejo para la producción de biomasas potencialmente útiles como partícula nutritivacon fines acuícolas.

  11. Lípidos sanguíneos en cerdos alimentados con pijiguao (Bactris gasipaes Kunth y lisina sintética

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    Janeth Colina R.

    2011-12-01

    Full Text Available Objetivo. Evaluar el efecto de la harina de pijiguao y lisina sintética sobre los lípidos sanguíneos de cerdos en crecimiento y engorde. Materiales y métodos. El estudio se realizó en dos etapas. En la primera etapa se utilizaron 72 cerdos castrados en crecimientode 30 ± 0.5 kg, en un arreglo factorial 2x3: dos niveles de lisina sintética (0 y 2.70 g/kgy tres niveles de harina de pijiguao (0, 160 y 320 g/kg. En la segunda etapa se utilizaron 16 cerdos en engorde de 67.25 ± 1.17 kg, en un arreglo factorial 2x2: dos niveles de lisinasintética (0 y 2.70 g/kg y dos niveles de pijiguao (0 y 175 g/kg. Se determinaron las concentraciones séricas de triacilgliceroles, colesterol total y ácidos grasos. Resultados. Los cerdos en crecimiento que consumieron pijiguao presentaron menores (p<0.001concentraciones de colesterol que el grupo control (2.27 y 2.23 mmol/l vs 2.56 mmol/l y triacilgliceroles (0.34 y 0.28 mmol/l vs 0.42 mmol/l. El ácido oleico incrementó (p<0.01con el mayor nivel de pijiguao (20.78% a 28.84%, y la lisina aumentó (p<0.05 el ácidolinoleico (27.83% a 31.29%. Los cerdos alimentados con pijiguao y lisina mostraron menor (p<0.001 ácido palmítico que el grupo con pijiguao sin lisina (0.23 y 0.19% vs 0.45 y 0.62%, respectivamente. En la etapa de engorde los triacilgliceroles disminuyeron (p<0.05 en los cerdos alimentados con pijiguao y lisina (0.46 a 0.36 mmol/l. Los cerdos alimentados con pijiguao mostraron menor ácido linoleico y mayor ácido oleico (p<0.001. Conclusiones. Las dietas con pijiguao y lisina sintética no causaron efectos negativos sobre los lípidos sanguíneos de cerdos.

  12. An integral term adaptive neural control of fed-batch fermentation biotechnological process; Control neuronal adaptable con termino integral para un proceso biotecnologico de fermentacion por lote alimentado

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    Baruch, Ieroham; Hernandez, Luis Alberto; Barrera Cortes, Josefina [Centro de Investigacion y de Estudios Avanzados, Instituto Politecnico Nacional, Mexico D.F. (Mexico)

    2005-07-15

    A nonlinear mathematical model of aerobic biotechnological process of a fed-batch fermentation system is derived using ordinary differential equations. A neurocontrol is applied using Recurrent Trainable Neural Network (RTNN) plus integral term; the first network performs an approximation of the plant's output; the second network generates the control signal so that the biomass concentration could be regulated by the nutrient influent flow rate into the bioreactor. [Spanish] Un modelo matematico no lineal de un proceso biotecnologico aerobio de un sistema de fermentacion por lote alimentado es presentado mediante ecuaciones diferenciales ordinarias. Es propuesto un control utilizando dos redes neuronales recurrentes entrenables (RNRE) con la adicion de un termino integral; la primera red representa un aproximador de la salida de la planta y la segunda genera la senal de control tal que la concentracion de la biomasa pueda ser regulada mediante la alimentacion de un flujo con nutrientes al biorreactor.

  13. Effect of alternative mediums on production and proximate composition of the microalgae Chaetoceros muelleri as food in culture of the copepod Acartia sp. Efecto de medios alternativos sobre la producción y composición proximal de la microalga Chaetoceros muelleri como alimento en cultivo del copépodo Acartia sp.

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    Luis R Martínez-Córdova

    2012-03-01

    . La biomasa y concentración celular finales también fueron más altas en Agr-F. Las microalgas de Agr-F y Aq-F tuvieron mayor contenido de carbohidratos y menor contenido de proteína en comparación con el control. No se observaron diferencias en los contenidos de lípidos y cenizas. Respecto a la producción de copépodos, las mayores densidades e índices de fecundidad se observaron en los organismos alimentados con microalgas producidas en Agr-F y Aq-F, en comparación con el control. La proporción adulto-nauplio también fue mayor en copépodos alimentados con microalga de Agr-F comparada con Aq-F y el control. Los copépodos alimentados con microalgas del Agr-F y Aq-F, tuvieron un mayor contenido de proteínas que el control; la cantidad de carbohidratos fue mayor en copépodos alimentados con microalga del Agr-F comparada con Aq-F. No se observaron diferencias en los contenidos de lípidos y cenizas. Agr-F y Aq-F fueron medios alternativos adecuados para producir C. muelleri, los cuales produjeron microalgas de alta calidad que incrementaron la producción de copépodos.

  14. Dinámica poblacional del rotífero Brachionus ibericus aislado de estanques para camarón, alimentado con diferentes dietas

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    José Cristóbal Román-Reyes

    2014-11-01

    Full Text Available La producción de microalgas vivas para cultivar rotíferos constituye uno de los mayores costos de operación en la larvicultura de peces, por lo que se están desarrollando sustitutos comerciales de microalgas para la alimentación y producción de rotíferos. Se desconoce el efecto que tienen las formulaciones comerciales sobre la dinámica poblacional de rotíferos nativos del noroeste de México y en este estudio se evaluó el efecto de cuatro dietas comerciales (Espirulina, RotiMac®, Nanno 3600®, RotiGrow-Plus® y la microalga viva Nannochloropsis sp., sobre el crecimiento poblacional y fecundidad del rotífero Brachionus ibericus (GenBank KJ949043, aislado de una granja de camarón blanco (Litopenaeus vannamei. Se realizaron cinco réplicas por tratamiento alimenticio utilizando recipientes con volumen de 12 L de agua, con temperatura de 29 ± 1°C y salinidad de 35 ± 1, respectivamente. Los resultados mostraron que durante los periodos experimentales, las dietas probadas resultaron adecuadas para alimentar a B. ibericus, con tasas de crecimiento, tiempos de duplicación, densidades máximas y fecundidades que fluctuaron entre 0.20 a 0.27 rotíferos día-1, 2.60 a 3.42 días, 215 a 344 rotíferos mL-1 y de 0.16 a 0.39 huevos hembra-1, respectivamente. Las diferencias entre tratamientos fueron significativas (P 0.05 a las obtenidas con Nanno 3600®.

  15. Cultivos discontinuos alimentados con urea de la cianobacteria Phormidium sp. en función de la salinidad y edad del cultivo

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    Lorena del valle Jonte Gómez

    2013-12-01

    Full Text Available Título en ingles: Urea fed-batch cultures of the cyanobacterium  Phormidium sp. as a function of the salinity and age of cultures Título corto: Cultivos discontinuos alimentados de Phormidium sp.Resumen: Se  Se comparó la eficiencia de sistemas de cultivos discontinuos alimentados versus cultivos discontinuos convencionales, en cuanto a concentración de nitrógeno, adicionando 0,2 mM de urea cada tres días al final de la fase exponencial, durante 21 días. Se realizaron cultivos con un volumen de 1500 mL a 15 y 35 UPS de salinidad, enriquecidos con medio ALGAL 8mM NaNO3, a 238 mmol q m-2 s-1, aireación constante, fotoperiodo 12:12 horas y temperatura de 29 ±3ºC. Phormidium sp. posee la capacidad de hidrolizar la urea; mostrando una asimilación de 65±7,07% de la misma, con la mayor producción (p´<´0,05 de clorofila a, ficocianina y proteínas de 20,26±1,24; 203,47±12,83 y 707,87±28,47 µg mL-1en los cultivos alimentados. La producción de pigmentos vario en el tiempo, independientemente a la salinidad y sistema de cultivo, mientras que la producción de proteínas y carbohidratos totales fue directamente proporcional a la edad del cultivo, con valores máximos de 612,74±5,41 µg mL-1 y 8,96±0,08 mg mL-1 respectivamente a los 31 días. La síntesis de lípidos y EPS fueron influenciadas (p´<´0,05 por la salinidad, presentando los máximos de lípidos a 15 UPS con 12,22±2,91mg mL-1, y los EPS se incrementaron a 35 UPS con 2,00±0,26 y 2,03±0,15 mg mL-1. Estos resultados determinan que los cultivos de Phormidium sp. alimentados con urea y a salinidades de 15 y 35 UPS, representan una alternativa económica para la producción de clorofila a, ficocianina y proteínas, incrementándose un 31,04; 40,72 y 31,94 % respectivamente en comparación con cultivos no alimentados.Palabras clave: clorofila, ficocianina, proteínas, cianobacteria, urea.Abstract: Fed-batch system efficiency versus batch cultures was compared in relation

  16. Utilización de la proteína dietaría por alevinos de la gamitana, Colossoma macropomum, alimentados con dietas isocalóricas

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    Félix Walter Gutiérrez

    2011-05-01

    Full Text Available Un experimento fue conducido para evaluar los efectos de cinco niveles de proteína (25,27, 29, 31 y 33% sobre el comportamiento productivo de alevinos de la gamitana, Colossoma macropomum Cuvier 1818, alimentados con dietas isocalóricas (2,7 kcal de ED/g. Los parámetros medidos fueron ganancia de peso (GP, conversión alimenticia (CA, proteína retenida (PR, razón de eficiencia proteica (REP y energía retenida (ER. En la preparación de las dietas experimentales se utilizaron como fuentes de proteína harina de anchoveta y harina de torta de soya y como fuentes de energía maíz amarillo duro, subproducto de trigo y aceite de pescado. Se encontraron diferencias significativas (P<0,05 entre tratamientos para los parámetros GP, PR, REP y ER. No se encontraron diferencias significativas para la CA. Los mejores rendimientos fueron obtenidos cuando las gamitanas fueron alimentadas con niveles dietarios de 25, 27 y 33% de proteína cruda. También se encontró que a medida que se elevó el nivel de proteína de la dieta, la REP decreció significativamente. Tomando en cuenta el costo de la proteína en la dieta, se concluye que la alimentación de la gamitana con niveles dietarios de 25 ó 27% de proteína cruda y 2,7 kcal de ED/g, garantizarán su exitoso crecimiento.

  17. COMPARACIÓN ENTRE EL SISTEMA DE ACABADO Y EL PESO AL SACRIFICIO SOBRE LA CALIDAD DE LA CARNE Y DE LA GRASA DE TERNEROS ALIMENTADOS CON RACIONES A BASE DE ENSILADOS

    OpenAIRE

    Zea Salgueiro, J.; Diaz Diaz, Mª D.; Carballo, J. A.

    2011-01-01

    Se comparan los efectos de los acabados de 45 o 90 días, en terneros machos y hembras, alimentados a base de ensilados, con pienso limitado (5 o 4 kg según sea ensilado de pradera o maíz, respectivamente) o a voluntad, con los efectos producidos por el aumento del peso de sacrificio (375,410 y 450 kg), en determinadas características de la carne: color, pérdidas de agua, veteado, consistencia, terneza, pH, composición química e índices nutricionales. En los ensayos de acabado los machos se sa...

  18. Comportamiento productivo de reproductoras porcinas alimentados con follaje fresco de Morus alba. IIndicadores hematológicos y estructurales

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    Contino Yuván; Ojeda Félix; Herrera Rafael; Altunaga Nancy; Pérez Guadalupe.

    2008-08-01

    Full Text Available El objetivo de esta investigación consistió en evaluar el comportamiento hematológico, morfométrico e histológico de las reproductoras porcinas alimentadas con follaje fresco de Morus alba (hojas y tallos tiernos como sustituto parcial del concentrado comercial en diferentes estados reproductivos comparadas con un grupo control el que no consumió el follaje fresco como sustituto parcial del concentrado. Las investigaciones se efectuaron en el Módulo de Investigación-Producción Porcina de la EEPF “Indio Hatuey. Los indicadores hematológicos medidos fueron el hematocrito, la hemoglobina y el leucograma con diferencial, en el Laboratorio Provincial del IMV ubicado en el municipio de Jovellanos. Elanálisis morfométrico de los órganos del tracto gastrointestinal,hemolinfopoyéticos y accesorios, se realizó mediante la medición y elpesaje en las reproductoras posterior al sacrificio. El rocesamiento histológico se realizó mediante la tinción hematoxilina-eosina. En el estudio estadístico se empleó el paquete SPSS Versión 10.1. Se obtuvo un mejor comportamiento hematológico, morfométrico e histológico al incluir en la dieta de las reproductoras el follaje de morera fresca como sustituto parcial del concentrado. Los resultados demuestran la factibilidad económica del empleo de esta alternativa alimentaría.

  19. Comportamiento productivo de cerdos en ceba alimentados con follaje fresco de Morus alba como sustituto parcial del concentrado

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    Contino Yuván| Ojeda Félix | Herrera Rafael | Altunaga Nancy | Pérez Guadalupe

    2008-08-01

    Full Text Available El objetivo de esta investigación consistió en evaluar la respuestaproductiva en la etapa de ceba en cerdos mestizos al emplear el follaje de morera fresca (hojas y tallos tiernos como sustituto parcial del concentrado comercial. La investigación se efectuó en el Módulo de Investigación-Producción Porcina de la EEPF ”Indio Hatuey” Se evaluaron las ganancias de peso vivo de cerdos en crecimiento desde los 30 kg hasta los 90 kg. El pesaje se realizó cada 14 días, con la determinación del peso vivo promedio, la ganancia media diaria, y la conversión alimentaría. Para el procesamiento se empleó el paquete estadístico SPSS versión 10.1. Se obtuvo un incremento de las ganancias medias diarias con el aumento del peso vivo y una mejor eficiencia en la dieta total por la utilización de lamorera. Los resultados demuestran la factibilidad económica de estaalternativa alimentaria

  20. Metabolitos sanguíneos en caprinos alimentados con mezclas integrales frescas con Moringa oleífera: Pennisetum purpureum Clon-OM22

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    Nelson Norberto González González; Delfín Gutiérrez González; Roberto García López; Aníbal Fernández Mayer

    2015-01-01

    Se evaluó el comportamiento de metabolitos sanguíneos energéticos y proteicos con el uso de mezclas de Moringa oleífera : Pennisetum purpureum clon OM-22. Se utilizaron cuatro machos caprinos de raza Alpina, con 37.78 ±4.87 kg de peso vivo, dos años de edad y alojados en jaulas metabólicas individuales, or - ganizados en un diseño cuadrado latino (4x4). El tiempo experimental fue 60 días, con cuatro periodos de 15 días. Los tratamientos consistie - ron en la inclusión creciente de ...

  1. Diseño y simulación de un balastro electrónico con corrección de factor de potencia con topología buck-boost e inversor alimentado por corriente

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    Germán E. Melo

    2014-08-01

    Full Text Available Las lámparas fluorescentes compactas o CFL (compact fluorescent lamp se han convertido en uno de los tipos de iluminación más usados en la actualidad. Sin embargo, las CFL comerciales poseen en su mayoría balastros electrónicos de bajo factor de potencia. Esto genera un aumento en los niveles de distorsión del sistema de generación y distribución debido al uso masivo de estas lámparas. En el presente artículo se presenta el diseño y simulación de un balastro electrónico con corrección de factor de potencia para lámparas fluorescentes compactas. La propuesta busca evaluar la viabilidad de integrar el correcto funcionamiento, tamaño y costo de este dispositivo. La topología propuesta es una etapa buck-boost operando en modo de conducción discontinua integrada a un inversor alimentado por corriente. La alta factibilidad de implementación de esta topología es mostrada mediante simulaciones que logran un factor de potencia de 0.998 y una distorsión total armónica menor de 5 %.

  2. Diseño y simulación de un balastro electrónico con corrección de factor de potencia con topología buck-boost e inversor alimentado por corriente

    Directory of Open Access Journals (Sweden)

    Germán E. Melo

    2014-05-01

    Full Text Available Las lámparas fluorescentes compactas o CFL (compact fluorescent lamp se han convertido en uno de los tipos de iluminación más usados en la actualidad. Sin embargo, las CFL comerciales poseen en su mayoría balastros electrónicos de bajo factor de potencia. Esto genera un aumento en los niveles de distorsión del sistema de generación y distribución debido al uso masivo de estas lámparas. En el presente artículo se presenta el diseño y simulación de un balastro electrónico con corrección de factor de potencia para lámparas fluorescentes compactas. La propuesta busca evaluar la viabilidad de integrar el correcto funcionamiento, tamaño y costo de este dispositivo. La topología propuesta es una etapa buck-boost operando en modo de conducción discontinua integrada a un inversor alimentado por corriente. La alta factibilidad de implementación de esta topología es mostrada mediante simulaciones que logran un factor de potencia de 0.998 y una distorsión total armónica menor de 5 %.

  3. Metabolitos sanguíneos en caprinos alimentados con mezclas integrales frescas con Moringa oleífera: Pennisetum purpureum Clon-OM22

    Directory of Open Access Journals (Sweden)

    Nelson Norberto González González

    2015-01-01

    Full Text Available Se evaluó el comportamiento de metabolitos sanguíneos energéticos y proteicos con el uso de mezclas de Moringa oleífera : Pennisetum purpureum clon OM-22. Se utilizaron cuatro machos caprinos de raza Alpina, con 37.78 ±4.87 kg de peso vivo, dos años de edad y alojados en jaulas metabólicas individuales, or - ganizados en un diseño cuadrado latino (4x4. El tiempo experimental fue 60 días, con cuatro periodos de 15 días. Los tratamientos consistie - ron en la inclusión creciente de Moringa oleífera (MO20%, MO40%, MO80% en sustitución de Pennisetum purpureum clon OM-22 (20:80, 40:60; 80:20% en la mezcla integral y un testigo, al que se le ofertó concentrado comer - cial (6g kg PV -1 . La totalidad de los forrajes frescos fueron cosechados, molidos (3-5cm y mezclados, ofertados a razón del 3% del peso vivo base seca, en dos ocasiones (10:30-16:30 horas durante el día. El estado de los metaboli - tos sanguíneo fue evaluado 22 horas posteriores al consumo de alimento. Las concentraciones de Glucosa, Colesterol, Triglicéridos y Urea se mantuvieron dentro del rango fisiológico. Los valores de Urea y Colesterol mostraron una ten - dencia creciente con la moringa en la mezcla, a diferencia de los Triglicéridos, que disminu - yeron. Los niveles de Creatinina en MO40 y MO80% superaron el límite fisiológico para la especie (59.7-134.8 μmol/l, indicando un posible fallo renal. Estos resultados permiten concluir que la Moringa oleífera con un nivel de inclusión del 20% constituye una alternativa alimentaria para caprinos; pero requiere de es - tudios para dilucidar niveles de Creatinina con la inclusión de 40 y 80% moringa.

  4. PRODUCCIÓN DE LA MICROALGA Nannochloropsis oculata (Droop) Hibberd EN MEDIOS ENRIQUECIDOS CON ENSILADO BIOLÓGICO DE PESCADO

    OpenAIRE

    2008-01-01

    Los residuos pesqueros se producen en grandes volúmenes en el Perú, generando problemas de contaminación, sin embargo, estos pueden ser un favorable sustrato para aplicaciones biotecnológicas. El ensilado biológico de pescado puede suplir a los medios de cultivo masivo basados en fertilizantes agrícolas para la producción de microalgas. Se cultivó a Nannochloropsis oculata en lote durante 12 días hasta alcanzar la fase estacionaria, con temperatura e iluminación constantes las 24 horas del dí...

  5. Monster potential meets potential monster: pros and cons of deploying genetically modified microalgae for biofuels production.

    Science.gov (United States)

    Flynn, K J; Mitra, A; Greenwell, H C; Sui, J

    2013-02-06

    Biofuels production from microalgae attracts much attention but remains an unproven technology. We explore routes to enhance production through modifications to a range of generic microalgal physiological characteristics. Our analysis shows that biofuels production may be enhanced ca fivefold through genetic modification (GM) of factors affecting growth rate, respiration, photoacclimation, photosynthesis efficiency and the minimum cell quotas for nitrogen and phosphorous (N : C and P : C). However, simulations indicate that the ideal GM microalgae for commercial deployment could, on escape to the environment, become a harmful algal bloom species par excellence, with attendant risks to ecosystems and livelihoods. In large measure, this is because an organism able to produce carbohydrate and/or lipid at high rates, providing stock metabolites for biofuels production, will also be able to attain a stoichiometric composition that will be far from optimal as food for the support of zooplankton growth. This composition could suppress or even halt the grazing activity that would otherwise control the microalgal growth in nature. In consequence, we recommend that the genetic manipulation of microalgae, with inherent consequences on a scale comparable to geoengineering, should be considered under strict international regulation.

  6. Análisis de la resistencia inmune en un modelo murino experimental alimentado con dietas lipídicas e infectado con Listeria monocytogenes Analysis of the immune resistance in an experimental murine model fed dietary lipids and infected with Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    M.ª A. Puertollano

    2004-11-01

    Full Text Available Algunas dietas lipídicas están implicadas en la reducción de ciertas funciones inmunes. Sin embargo, la acción inmunosupresora de estas dietas puede tener efectos adversos sobre la resistencia inmune del individuo frente a enfermedades de naturaleza infecciosa. En el presente estudio tratamos de valorar el estado inmune de ratones alimentados con dietas lipídicas e infectados experimentalmente con una cepa virulenta de Listeria monocytogenes. Ratones de la raza Balb/c fueron divididos en cuatro grupos alimentados cada uno de ellos con su respectiva dieta: dieta baja en lípidos (control, 2,5%, dieta rica en aceite de oliva (AO, 20%, dieta rica en aceite de pescado (AP, 20% y dieta rica aceite de coco (AC, 20%. Los animales fueron alimentados durante un mes y posteriormente infectados con L. monocytogenes por vía endovenosa. Los resultados han mostrado una reducción de la supervivencia en animales alimentados con AP, así como un incremento significativo en el número de bacterias viables aisladas a partir de bazo. Además hemos podido observar un aumento de la capacidad bactericida de células peritoneales procedentes de ratones alimentados con AO, aunque la invasividad de L. monocytogenes en este grupo fue mayor que en el resto. Finalmente, una reducción significativa de la linfoproliferación fue observada en el grupo alimentado con AP, mientras que la actividad de células natural killer (NK no se ha visto modificada. Estos resultados indican que dietas lipídicas constituidas por ácidos grasos poliinsaturados de la serie n-3 reducen la resistencia inmune de los ratones, mientras que una dieta constituida por AO no produce un efecto inmusupresor tan relevante y por consiguiente no reduce drásticamente la resistencia inmune siendo más eficiente en la eliminación de L. monocytogenes.Several dietary lipids are capable of exerting an immunosupressor effect. This action may have undiserable effects on the host immune resistance to

  7. Evaluación del crecimiento del pulpo común Octopus mimus del norte de Chile alimentado con dietas formuladas Growth evaluation of octopus (Octopus mimus from northern Chile fed with formulated diets

    Directory of Open Access Journals (Sweden)

    Oscar Zúñiga

    2011-11-01

    Full Text Available Durante 57 días se comparó el crecimiento y sobreviviencia de pulpos juveniles Octopus mimus del norte de Chile alimentados con tres diferentes dietas: dos dietas húmedas (A y B aglutinadas con solución de gelatina embutidas en tripa de cordero y una dieta control (C natural. La dieta (A fue elaborada en base a una mezcla de filete triturado del pescado Cheilodactylus variegatus con harina de pellet para salmón, la dieta (B con pasta de almeja (Protothaca thaca mezclada con filete de Ch. variegatus y la dieta control consistió en el suministro de almejas frescas congeladas (C. Basado en un diseño experimental de medidas repetidas, los pulpos se mantuvieron individualmente en estanques de 70 L con circulación de agua de mar y aireación permanente. Los pulpos que consumieron la dieta B no experimentaron mortalidad y la dieta control C presentó mortalidad del 16,7%, sus crecimiento fueron similares (P > 0,05 con tasas de crecimiento absoluta (AGR de 7,0 ± 0,91 (g d-1 y 6,6 ± 1,10 (g d-1 respectivamente. Los pulpos alimentados con la dieta A registraron mortalidad de 33,3% y tasa de crecimiento absoluta negativa, AGR= -1,70 ± 0,37 (g d-1. La dieta A que contenía como ingrediente pellet para salmón molido como harina no tuvo una adecuada aceptación y los ejemplares experimentaron disminución de su peso. La dieta B preparada con gelatina de origen animal como aglutinante, no implicó un efecto negativo en la palatabilidad y aceptabilidad en comparación al control basada en almeja fresca congelada, incluso los organismos lograron crecimientos similares. Los resultados permitirán a futuro mejorar la calidad nutricional de dietas artificiales para maximizar el crecimiento de O. mimus en cautiverio.The growth and survival of juvenile octopus, Octopus mimus, from northern Chile, fed three different diets were analyze during 57 days. Two of the diets (A and B were wet diets stuffed in lamb gut with a gelatin solution, and the third (C was

  8. Crecimiento y composición corporal en prematuros extremos alimentados mediante fórmulas con diferente contenido proteico-calórico

    OpenAIRE

    Costa Orvay, Juan Antonio

    2009-01-01

    OBJETIVOS: Determinar el efecto de una dieta enteral hipercalórica e hiperproteica sobre el crecimiento y la composición corporal en prematuros extremos. Valorar la aparición de efectos adversos secundarios. METODOS: Se plantea un estudio clínico longitudinal de asignación sistematizada tipo cohorte con cuatro grupos (LM, A, B y C) desde enero 2006 a enero 2008. Cada paciente es seguido durante 21 días. El estudio es aprobado por el Comité ético de investigación clínica del Hospital Clínic i ...

  9. Desarrollo de Moina sp en condiciones de laboratorio alimentada con microalgas cultivadas en residuales pesqueros (Development of Moina sp. In laboratory conditions, fed with microalgae cultured in the waste waters of fishing industry

    Directory of Open Access Journals (Sweden)

    Romero-López, Teresita de J.

    2009-04-01

    Full Text Available ResumenEl cladócero Moina sp se cultivó en condiciones controladas de laboratorio, con una densidad inicial de 130 org/500 mL, aplicando a los organismos de prueba Scenedesmus sp desarrollada en residual pesquero, a razón de 650 cel/mm3 y 1 300 cel/mm3 como única fuente de alimentación. Como resultado se obtuvo que la densidad del zooplancton ascendió a 3,0 org/mL como promedio en ambos tratamientos, sin presentarse diferencias estadísticas significativa entre ellos, para un rendimiento (r entre 0,3 y 0,4 org/mL.d y un tiempo de duplicación (Td entre 2,7 y y 3,3 d. Se concluyó que esta microalga cultivada en efluentes industriales satisface losrequerimientos nutricionales de Moina sp, aunque es recomendable suingestión con otra fuente de alimento que podría aumentar la densidad de organismos en las condiciones dadas.SummaryWith the objective to evaluate the development of Moina sp fed withmicroalgae cultured in the waste water from the fishing industry anexperimental completely completely randomized design was made with twotreatments and three repetition each one. Recipients with 500 mL volume filled with tap water enriched with lime hydroxide. In each one 130 Moina sp individuals were seeded. In the feeding of Moina was used microalgae Scenedesmus sp in two concentrations (A 650 cel/mm3 and (B 1 300 cel/mm3. Significant statistical differences (p>0, 05 between the applied treatments were not observed. The density of zooplankton increased up to 3.0 org/mL in both treatments and the yield were of 0, 4 and 0, 3 org/mL.d and a duplication time of 2,7 and 3,3 days respectively.

  10. Fatty Acid Composition of Longissimus dorsi Muscle of Suffolk Down Lambs Fed on Different Dryland Forages Composición de Ácidos Grasos del Músculo Longissimus dorsi de Corderos Suffolk Down Alimentados con Diferentes Forrajes

    Directory of Open Access Journals (Sweden)

    María Asunción Gallardo

    2011-12-01

    , poliinsaturados (PUFA, y razón omega 6/omega 3 (06/03. Hubo una tendencia (p > 0,06 hacia un mayor contenido de ácidos grasos monoinsaturados (MUFA en la carne de corderos alimentados con trébol rosado, comparado con los otros tipos de praderas. Aunque no hubo diferencias significativas entre tratamientos, los resultados obtenidos con la pradera sucesional no pueden ser extrapolados a pasturas naturales en el secano, debido a sus altos contenidos de leguminosas. Se concluye que el uso de trébol subterráneo proveería una similar calidad de carne, al comparar con forrajes basados en trébol rosado.

  11. Microbial protein synthesis in young steers fed with grass silage and extruded corn Síntesis de proteína microbiana en novillos jóvenes alimentados con ensilaje de praderas y maíz extruido

    Directory of Open Access Journals (Sweden)

    Claudia Barchiesi-Ferrari

    2012-12-01

    Full Text Available Microbial protein synthesis is essential to meet protein requirements in ruminants. The aim of this investigation was to evaluate the effect of incorporating extruded corn (Zea mays L. into the ration of young steers fed with grass silage on microbial protein synthesis (MPS. Twenty young steers in metabolic cages were used for supplying food. The treatments consisted of combinations of extruded corn (EC and ground corn (GC EC-10 (10% EC-30% GC; EC-25 (25% EC-15% GC and EC-40 (40% EC-0% GC. These foods constituted 40% of the ration (DM-based and the remaining 60% was grass silage. The MPS was calculated through the excretion of purine derivatives (PD in the urine, using total collection of urine. The inclusion of a higher percentage of extruded corn (EC-40 increased the PD excretion (51.85 mmol d-1, P La síntesis de proteína microbiana es fundamental para satisfacer los requerimientos proteicos en rumiantes. El objetivo de esta investigation fue evaluar el efecto de incluir maíz (Zea mays L. extruido en la ración de novillos alimentados con ensilaje de pradera, sobre la sintesis de proteina microbiana (MPS. Se emplearon 20 novillos jóvenes ubicados en jaulas metabólicas para suministro de los alimentos. Los tratamientos consistieron en combinaciones de maiz extruido (EC y maiz molido (GC EC-10 (10% EC-30% GC; EC-25 (25% EC-15% GC y EC-40 (40% EC-0% GC. Estos alimentos constituyeron el 40% de la ración (base MS y el restante 60% fue ensilaje de pradera. Se estimó la MPS a través de la excreción de derivados de purinas (PD en la orina, empleando colección total de orina. La inclusión de un mayor porcentaje de EC (EC-40 incrementó la excreción de PD (51.85 mmol d-1, P < 0,05. Los valores de excreción de PD fluctuaron entre 663 y 1078 μmol BW-075 d-1. La absorción de proteína microbiana y el flujo de N duodenal también se incrementaron por una mayor inclusión de EC (EC-40, P < 0,05. Las diferencias entre los tratamientos pueden

  12. Respuesta productiva de conejos alimentados con forraje verde hidropónico de avena, como reemplazo parcial de concentrado comercial Productive response of rabbits fed with green hydroponic oats forage as partial replacement of commercial concentrate

    Directory of Open Access Journals (Sweden)

    Francisco Fabián Fuentes Carmona

    2011-04-01

    Full Text Available La respuesta productiva de conejos raza californiana alimentados con forraje verde hidropónico (FVH de avena como reemplazo parcial de concentrado comercial (CC, fue evaluada en condiciones de desierto en el norte de Chile. Se establecieron cinco tratamientos de alimentación, equivalentes a 0, 25, 50, 75 y 100% de reemplazo de la dieta diaria con FVH, el cual fue cosechado y utilizado directamente diez días después de la siembra. Cuarenta y cinco conejos destetados a los 31 días fueron evaluados en un diseño completamente al azar hasta alcanzar un peso de sacrificio de 2 kg de peso vivo. La calidad del FVH de avena fue considerada como buena, presentando similar valor nutritivo que el CC. Las variables evaluadas y sus respectivos rangos fueron: consumo de materia seca promedio (59.17 - 104.73 g/día, ganancia de peso vivo promedio (16.35 - 29.10 g/animal por día, conversión alimenticia promedio (3.31 - 3.93 kg MS/kg PV, tiempo de peso vivo a sacrificio (53 - 91 días, peso vivo final (1430 - 2044 g/animal, peso de la canal (1235 - 1385 g/animal y rendimiento de la canal (59.19 - 62.25%. El reemplazo de hasta 50% de la dieta base con FVH de avena no afectó significativamente (P The productive response of Californian rabbits fed with hydroponic green oats forage (HGOF as a partial replacement of commercial concentrate (CC was evaluated under desert conditions in northern Chile. Five treatments were established as follow: 0, 25, 50, 75 and 100% replacement of daily diet with HGOF, which was harvested and used directly at 10 days after sowing. Forty-five rabbits weaned at 31 days were evaluated in a completely randomized design until slaughter weight of 2.0 kg. HGOF quality was considered as good, presenting similar nutritional value to CC. The variables assessed and range values were: average dry matter intake (59.17-104.73 g/d, average weight gain (16.35-29.10 g/ rabbit for day, feed conversion average (3.31-3.93 kg DM/ kg LW, time of

  13. Enhancement of superoxide dismutase and catalase activity in juvenile brown shrimp, Farfantepenaeus californiensis (Holmes, 1900, fed β-1.3 glucan vitamin E, and β-carotene and infected with white spot syndrome virus Incremento de la actividad superóxido dismutasa y catalasa en juveniles de camarón café Farfantepenaeus californiensis (Holmes, 1900 alimentados con β-1,3 glucano vitamina E y β-caroteno e infectados con el virus de la mancha blanca

    Directory of Open Access Journals (Sweden)

    Rosario Pacheco

    2011-11-01

    contenedores de fibra de vidrio de 60 L y se alimentaron diariamente durante 23 días con β-1,3-glucano (0,1%, vitamina E (0,01%, y β-caroteno (0,01% y posteriormente se inocularon con WSSV. Se determinó la actividad antioxidante de la enzima superóxido dismutasa (SOD y catalasa (CAT en hepatopáncreas y músculo a las 0, 1, 6, 12, 24 y 48 h después de la infección. Los grupos de camarones alimentados con los tratamientos incrementaron la actividad SOD en el hepatopáncreas y músculo a las 12 y 24 h después de la infección, respectivamente. Los juveniles tratados con vitamina E y β-1,3-glucano mantuvieron un incremento en la actividad SOD desde las 12 a 48 h postinfección. Los camarones alimentados con β-caroteno incrementaron la actividad de SOD antes de la infección con WSSV y los que fueron alimentados con β-1,3-glucano y vitamina E incrementaron la actividad CAT también antes de la infección. La actividad CAT en músculo se incrementó respecto al grupo control, con todos los grupos de camarones tratados desde 1 hasta 6 h posteriores a la inoculación con WSSV. La actividad antioxidante más alta se registró en los camarones alimentados con vitamina E. Los juveniles alimentados con vitamina E y posteriormente inoculados con WSSV, registraron 100% de mortalidad a las 72 h, pero los que fueron alimentados con β-1,3-glucano y β-caroteno resistieron la infección hasta las 144 h. Los resultados de Antioxidant response in F. californiensis fed with dietary supplements and infected with WSSV este estudio mostraron la capacidad de juveniles de Farfantepenaeus californiensis alimentados con β-1,3-glucano, vitamina E o β-caroteno, de incrementar la respuesta antioxidante antes y durante una infección viral.

  14. Comparación de la ganancia de peso de neonatos prematuros alimentados con lactancia materna exclusiva con énfasis en la fracción emulsión, lactancia mixta y sucedáneos

    OpenAIRE

    Velásquez Barahona, Gloria

    2015-01-01

    Objetivo: Determinar si los bebés prematuros que se alimentaban con lactancia materna exclusiva con énfasis en la fracción emulsión, ganaban peso adecuadamente, comparable a los que se alimentan con lactancia mixta o sucedáneos  y así obtener evidencia clínica que apoye el uso de lactancia materna exclusiva, utilizando esta técnica, en los neonatos prematuros. Método: El estudio fue de tipo experimental longitudinal por  2 meses y medio entre el 31 de agosto al 27 de septiembre del año 2007 e...

  15. - Valor nutritivo del ensilado de pastos tropicales III. Fermentación ruminal en carneros alimentados con ensilado sólo o suplementado con energía y/o proteína.

    Directory of Open Access Journals (Sweden)

    R. Ayala

    2006-03-01

    Full Text Available Resumen Se evaluó el efecto de la suplementación con proteína y/o energía en la fermentación ruminal de 3 carneros adultos mestizos de criollo con un peso vivo promedio de 29 kg fistulados en el rumen a través de un análisis de de varianza mediante un modelo lineal. Los tratamiento consistieron en: Ensilado a voluntad (E; ensilado más melaza (E+M; ensilado más harina de pescado (E+HP y ensilado más miel más harina de pescado (E+M+HP. La melaza y la harina de pescado se suministraron a razón de 8.2 y 7.2 g/kg¾ (base húmeda respectivamente. Las concentraciones de ácido láctico en el rumen fueron más elevadas (p<0.001 en los tratamientos de E+M (1.14 y E+M+HP(1.00 mmol/L que en las restantes dietas y los niveles de amoníaco más alto (P<0.001 en las raciones de E+HP (17.48 mg/ 100 ml comparado con E+M+HP (12.50. Hubo diferencia altamente significativa (p<0.001 en las concentraciones de nitrógeno total y nitrógeno no proteico entre todos los tratamientos siendo en el orden decreciente como sigue: E+M+HP: E+HP: E y E+M. Al parecer la suplementación con melaza sola a un ensilado de bajo contenido proteico (<7% no mejoró la eficiencia de utilización de nitrógeno amoniacal en el rumen.

  16. Public health intervention linked to a toxic microalgae bloom in Mijas beach (Malaga, Spain); Intervencion en salud publica relacionada con la proliferacion de microalgas toxicas en una playa de Mijas (Malaga; Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Gamez de la Hoz, J.; Padilla Fortes, A.

    2012-07-01

    This paper provide an overview of the surveillance environmental efforts and risk management for the public health linked to the register of a disease outbreak related to an episode of toxic potentially and harmful microalgae, identified during the summer of 2010 in a recreational beach of a touristic municipality in the coast of Malaga (Spain). Phytoplankton analyses showed the presence of different species producers of marine biotoxins, dominating Ostreopsis cf. ovata in the followed immediately days to the communication of 39 clinical cases of people that required health cares. The risks of the toxins produced by microalgae must be taken into account in the health networks surveillance for recreational waters. This study suggests the possibility to review the actions of the public health services from Public Administration, to the light of the increasing information on episodic harmful algal blooms. (Author)

  17. Analytical Issues on the Determination of Carotenoids in Microalgae by Liquid Chromatography with Diode Array Detector; Aspectos Analiticos sobre la Determinacion de Compuestos Carotenoides en Microalgas mediante Cromatografia de Liquidos con Detector de Diodos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R. M.

    2012-04-11

    A preliminary study of literature review on the determination of carotenoids in microalgae samples by HPLC with diode array detector is presented. Main objective has been focused to compile data from literature and based on the main aspects of the analytical methodology used in the determination of these compounds. The work is structured as follows and affecting major analytical difficulties: Procurement and commercial availability of standard solutions. Stage of sample treatment. Chromatographic analysis. (Author) 19 refs.

  18. Microalgae Nutraceuticals

    Directory of Open Access Journals (Sweden)

    Marcello Nicoletti

    2016-08-01

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

  19. Diseño y Construcción de un sistema de Ozonificación para purificación de agua alimentado con Energía Solar.

    OpenAIRE

    Sànchez Vega, Guadalupe Omar

    2016-01-01

    En el trabajo que a continuación se presenta se realizó el diseño y construcción de un sistema de purificación de agua por medio del proceso de ozonificación que opera totalmente con energía solar. Para su dimensionamiento se tomaron en cuenta gran cantidad de variables (como la presión del gas de alimentación, voltaje, frecuencia, por destacar algunas) para obtener una mayor cantidad de ozono con bajos consumos energéticos, los cuales son capaces de ser abastecidos con una pila de 12 V y 17 ...

  20. Mice fed with a high fat diet show a decrease in the expression of "toll like receptor" (TLR2 and TLR6 mRNAs in adipose and hepatic tissues El tejido adiposo y el tejido hepático de los ratones alimentados con una dieta alta en grasa tienen un decremento en la expresión del mRNA del "toll like receptor" (TLR2 y del TLR6

    Directory of Open Access Journals (Sweden)

    G. Betanzos-Cabrera

    2012-08-01

    inflamatorio que conduce a una resistencia a la insulina en el tejido graso. Objetivo: En este trabajo, nosotros investigamos si los otros miembros de la familia de los PRRs podrían también participar en el proceso inflamatorio del tejido adiposo de los ratones obesos. Métodos: La expresión del mRNA de los TLRs, del NLRP3-inflamasoma (constituido por las moléculas NLRP3, ASC, caspasa-1 e IL-lbeta, de las citocinas inflamatorias IL-6 y TNFα fue estudiado, por RT-PCR, en el tejido adiposo y en el tejido hepático de ratones alimentados con una dieta alta en grasa (HFD. Resultados: El tejido adiposo de los ratones alimentados con una HFD tuvieron un nivel bajo de expresión de TLR2, TLR6 y TLR7 en comparación a los ratones controles y este nivel fue también presente en el tejido hepático. La expresión de la IL-6 y el TNF-α se decremento en el tejido adiposo de los ratones alimentados con HFD. La expresión del NLRP3-inflamasoma no fue modificado. Conclusión: Estos resultados sugieren que el nivel bajo de expresión del TLR2 y del TLR6 en los ratones alimentados con HFD podrían estar regulando la inflamación inducida por la dieta empleada en este estudio.

  1. Composición química y calidad sensorial de jamones curados provenientes de cerdos alimentados con una dieta rica en ácido oleico y pasturas

    Directory of Open Access Journals (Sweden)

    Ana Echenique

    2011-05-01

    Full Text Available La dieta animal es uno de los factores que más incide sobre la calidad de los productos porcinos. En este trabajo se evaluó el efecto de la utilización de semilla de girasol de alto oleico (SGAO y pasturas sobre la calidad química y sensorial del jamón curado. Se analizaron jamones provenientes de 60 cerdos faenados a los 145 kg. Éstos fueron sometidos a cuatro tratamientos, consistentes en el suministro de dietas con diferente aporte lipídico en cantidad y composición química, con y sin acceso a pasturas: i ración estándar, sin pasturas; ii ración estándar, con pasturas; iii ración con SGAO, sin pasturas, y iv ración con SGAO, con pasturas.Se evaluaron parámetros físico-químicos y sensoriales de jamones obtenidos luego de un curado tradicional de nueve meses. La ración con SGAO dio lugar a jamones con una mayor proporción de C18:1(9 y menor de ácidos grasos saturados en relación a la estándar. Las pasturas incidieron sobre el color y determinaron una mayor proporción de C18:3(3 y C22:6(3. Se concluye que con una dieta compuesta por SGAO y pasturas se obtienen jamones con mayor proporción de ácidos grasos oleico y 3 yrelaciones 6/3 más favorables para la salud humana, sin que se vean afectados atributos sensoriales.Palabras clave: Porcinos, sistema de alimentación, ácidos grasos, calidad.AbstractOne of the most important factors that determine the quality of pork products is the pig´s diet. This study was performed to evaluate the use of sun ower seed with high oleic acid (HOSS and the use of pastures on the chemical and sensorial quality of dry-cured ham. Dry-cured hams from 60 pigs slaughtered at 145 kg were analyzed. These animals were fed with two diets with different lipid content and chemical composition, and with and without access to pastures: i standard diet without pastures;ii standard diet with pastures; iii diet with HOSS without pastures and iv diet with HOSS with pastures. Dry-cured hams obtained after

  2. Análisis de indicadores de rendimiento biológico y económico en la producción de dos híbridos de pollos de engorde alimentados con tres alimentos comerciales (ING)

    OpenAIRE

    José Rodríguez Zelaya; Diego Aguirre Rosales; Olga Flora Hidalgo Villegas

    2016-01-01

    Un total de 180 pollos de engorde, 90 del híbrido H1 y 90 del híbrido H2, de un día de nacidos, sin sexar,  fueron distribuidos de acuerdo con un arreglo factorial 2 x 3 en un diseño irrestrictamente al azar, dividido en dos etapas (iniciación y finalización). En ambas etapas el agua y el alimento se suministraron ad libitum. Se utilizaron alimentos comerciales específicos para cada etapa (A1, A2, A3). El periodo experimental fue de 49 días y las aves se pesaron semanalmente, así como el ...

  3. Parámetros hematológicos y bioquímicos en el hámster dorado (Mesocricetus auratus L. alimentado con base en harina de lombriz roja (Eisenia spp. y fuentes convencionales

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    L. Cova

    2011-01-01

    Full Text Available Se evaluó durante 21 días el efecto de cuatro dietas proteicas con base en harina de Lombriz Roja (Hl (Eisenia spp. (nivel de inclusión de Hl: D1: 21; D2: 24; D3: 27 y D4: 30% y dos alimentos convencionales: Conejarina ® (D0 y Ratarina® (D5 en algunos parámetros hematológicos y bioquímicos en el hámster dorado (Mesocrisetus auratus L. mediante un diseño totalmente aleatorizado para un factor, en el estado Trujillo, Venezuela. El hematocrito (37.65-41.01%, la hemoglobina (10.83-12.25%, la bilirrubina total, directa e indirecta (0.20-0.40; 0.10-0.22; 0.10-0.20mg/ dL, respectivamente, las lipoproteínas de muy baja densidad (Vldl (15.12-41.27mg/dL; los triglicéridos (95.42-190.54mg/dL; así como los valores de Calcio (Ca (9.83-12.32 mg/dL y Potasio (4.24-5.43mg/dL no exhibieron diferencias significativas entre dietas (P>0,05. Los leucocitos (Lto, las plaquetas (Plq, el conteo diferencial (neutrófilos/linfocitos (Linf/eosinófilos, la glicemia (Glc, la amilasa, el colesterol total, las lipoproteínas de elevada (Hdl y baja densidad y el Fósforo mostraron variaciones sustanciales entre los tratamientos (P<0,05. Los niveles crecientes de proteína de las dietas no afectaron los parámetros evaluados. Sin embargo, se observó una relación negativa entre la inclusión de Hl y las cantidades de Lto (r=-0.76**, Plq (r=-0.76**, Linf (r=-0.71**, Glc (r=-0.58* y Hdl (r=-0.50*. La adición de hl en proporciones de 24, 27 y 30% para obtener alimentos formulados entre 13.5 y 19.6% de proteína, para M. auratus, afecta algunos de los parámetros hematológicos y la concentración sérica de metabolitos relacionados con la composición nutricional de la dieta.

  4. Assessment of Blood Chemistry, Weight Gain and Linear Body Measurements of Pre-Puberal Buck Rabbits Fed Different Levels of Neem (Azadirachta indica A. Juss. Leaf Meals Evaluación de Química Sanguínea, Ganancia de Peso y Mediciones Corporales Lineales de Conejos Pre-Púberes Alimentados con Diferentes Niveles de Harina de Hojas de Neem (Azadirachta indica A. Juss.

    Directory of Open Access Journals (Sweden)

    I.P Ogbuewu

    2010-09-01

    Full Text Available A 16 week feeding trial was carried out to investigate the effect of dietary Neem (Azadirachta indica A. Juss. leaf meal (NLM on body weight gain, linear body measurements and blood chemistry of pre-puberal buck rabbits. Four treatment diets were formulated to contain the NLM at inclusion levels of 0 (control, 5, 10 and 15%. Thirty six crossbred New Zealand white × Chinchilla pre-puberal buck rabbits aged 5 to 6 mo were divided into four groups of nine rabbits and each group was further replicated into three of three rabbits each. The rabbits were randomly assigned to the four dietary treatments. Lymphocyte count of rabbits fed control diet (8.32 × 10(9 mm-3 was significantly higher than the group fed 15% NLM (4.60 × 10(9 mm-3. The mean cell hemoglobin (MCH and mean cell volume (MCV of the control bucks were significantly (p 0.05 among the treatment groups. The results suggest that buck rabbits could tolerate up to 15% dietary inclusion of NLM without deleterious effects on body weight gain, linear body measurements and some hematological parameters.Se realizó un ensayo de alimentación de 16 semanas para investigar el efecto de harina de hojas de neem Azadirachta indica A. Juss. (NML sobre ganancia de peso, mediciones corporales lineales y química sanguínea de conejos machos pre-púberes. Se formularon cuatro dietas con niveles de inclusión de NLM de 0 (control, 5, 10, y 15%. Treinta y seis conejos híbridos New Zealand white × Chinchilla, pre-púberes, de 5 a 6 meses, se distribuyeron en cuatro grupos de nueve conejos, y cada grupo fue repetido en tres grupos de tres conejos cada uno. Los conejos se asignaron aleatoriamente a las cuatro dietas tratamiento. El recuento de linfocitos de los conejos alimentados con la dieta control (8,32 × 10(9 mm-3 fue significativamente mayor que el grupo alimentado con 15% NLM (4,60 × 10(9 mm-3. La hemoglobina celular media (MCH y el volumen celular medio (MCV de los conejos control fueron

  5. Efecto de la coinmovilización de la microalga Chlorella sorokiniana con la bacteria promotora de crecimiento vegetal Azospirillum brasilense, en el crecimiento poblacional microalgal y capacidad de remoción de amonio como uso potencial en el tratamiento..

    Directory of Open Access Journals (Sweden)

    Guillot Monroy Gabriel

    2006-06-01

    Full Text Available Se desarrollaron dos experimentos de coinmovilización de la microalga Chlorella sorokiniana con la bacteria promotora
    de crecimiento vegetal (PGPB Azospirillum brasilense en esferas de alginato, para evaluar la influencia de la bacteria en el crecimiento poblacional y en la capacidad de remoción de amonio de la microalga; con el fin de establecer el potencial que pueda tener la coinmovilización de estos microorganismos en el tratamiento terciario de aguas residuales. Los resultados revelan un significativo incremento de la población cuando C.
    sorokiniana es coinmovilizada con A. brasilense, aunque no se observó un efecto significativo en la remoción de amonio. Los resultados obtenidos en el presente trabajo, reflejan la importancia de avanzar en el estudio de un sistema coinmovilizado altamente eficiente para ser utilizado en tratamiento de aguas residuales. La coinmovilización
    de C. sorokiniana con A. brasilense, muestra la habilidad de esta bacteria para influir de manera positiva en el crecimiento y fisiología de la microalga y por lo tanto la remoción de amonio puede ser incrementada.

  6. Comparación entre la ganancia de peso de neonatos prematuros alimentados con lactancia materna exclusiva (con énfasis en la fracción emulsión) y los de lactancia mixta o sucedáneos

    OpenAIRE

    Gloria Velásquez-Barahona

    2014-01-01

    Antecedentes. Las intervenciones relacionadas con la alimentación en los neonatos prematuros promueven tanto la salud inmediata como a lo largo de la vida y tienen un impacto significativo en los niveles de morbimortalidad neonatal e infantil (3). Objetivo. Determinar si los bebés prematuros que se alimentaban con lactancia materna exclusiva (LME) con énfasis en la fracción emulsión -final de la toma-, ganaron peso adecuadamente, comparados con los que se alimentan con lactancia mixta (LMM) o...

  7. Brote con síntomas respiratorios en la provincia de Almería por una posible exposición a microalgas tóxicas An epidemic outbreak with respiratory symptoms in the province of Almeria (Spain due to toxic microalgae exposure

    Directory of Open Access Journals (Sweden)

    Pilar Barroso García

    2008-12-01

    Full Text Available Objetivos: Describir un brote con clínica de irritación de las vías respiratorias, notificado en una localidad de la costa almeriense en agosto de 2006, así como la investigación etiológica realizada. Métodos: Estudio descriptivo y de casos y controles. Se dividió la localidad en 3 zonas según su mayor o menor cercanía al mar (de 1 a 3. La sintomatología fue valorada subjetivamente de menor a mayor gravedad (1 a 3. Se estimaron las tasas de ataque (TA. Para relacionar la gravedad de los síntomas por zonas y el tipo de exposición se calcularon las odds ratio (OR y sus intervalos de confianza del 95% (IC95%. También se utilizó la prueba de la χ2 y el test exacto de Fisher. Se realizó una investigación ambiental. Resultados: Se encuestó a 57 casos y 26 controles. Se estimó una TA del 69%. El síntoma más frecuente fue el estornudo (87,7%. Los individuos de la zona 1 presentaron mayor riesgo de padecer sintomatología de más gravedad que los de la zona 3 (OR = 46,7; IC95%: 4,7-2.067,4. Los que indicaron una mayor permanencia fuera de la vivienda tuvieron mayor riesgo de enfermar (OR = 12,2; IC95%: 1,1-615,1. En agua de mar se detectaron 1.200 células/l de dinoflagelados Ostreopsis. Conclusiones: Se trata de un brote con sintomatología respiratoria, con distinto grado de afectación según la cercanía al mar de la vivienda. Según la investigación epidemiológica y ambiental, lo más probable es que se haya debido a la presencia de microalgas tóxicas Ostreopsis.Aim: To describe an outbreak with symptoms of respiratory tract irritation reported in a village located on the Almerian coast in August 2006, as well as the etiological research performed. Methods: We performed a descriptive case-control study. The village was divided into three areas (from 1 to 3 according to the distance from the sea. Symptomatology was subjectively assessed on an ascending severity scale (from 1 to 3. Attack rates (AR were estimated. To correlate

  8. Microalgae: biofuel production

    Directory of Open Access Journals (Sweden)

    Babita Kumari

    2013-04-01

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

  9. MICROALGAE AS TOCOPHEROL PRODUCERS

    Directory of Open Access Journals (Sweden)

    V. M. Mokrosnop

    2014-04-01

    Full Text Available Microalgae are able to accumulate considerable amounts of tocopherols (up to 4 mg/g dry weight. The content of α-tocopherol to plant oils is low, whereas microalgae contain up to 97% of the tocochromanols that provides high bioactivity. The data about the content of tocopherols in eukaryotic microalgae Dunaliella tertiolecta, Nannochloropsis oculata, Isochrysis galbana, Euglena gracilis, Tetraselmis suecica, Diacronema vlkianum, as well as in the cyanobacterium Spirulina platensis are given in the paper. The largest amounts of tocopherols are synthesized by Euglena gracilis cells at mixotrophic cultivation. The level of tocopherols in microalgae depends on cultivation conditions. Two-stage biotech cultivation techniques, limiting nutrition in some biogenic elements, the introduction of exogenous carbon sources are used to increase the yield of tocopherol from microalgae. The approaches to the genetic transformation of plants leading to higher content of active vitamin E are rewieved as well.

  10. Comparación entre la ganancia de peso de neonatos prematuros alimentados con lactancia materna exclusiva (con énfasis en la fracción emulsión y los de lactancia mixta o sucedáneos

    Directory of Open Access Journals (Sweden)

    Gloria Velásquez-Barahona

    2014-12-01

    Full Text Available Antecedentes. Las intervenciones relacionadas con la alimentación en los neonatos prematuros promueven tanto la salud inmediata como a lo largo de la vida y tienen un impacto significativo en los niveles de morbimortalidad neonatal e infantil (3. Objetivo. Determinar si los bebés prematuros que se alimentaban con lactancia materna exclusiva (LME con énfasis en la fracción emulsión -final de la toma-, ganaron peso adecuadamente, comparados con los que se alimentan con lactancia mixta (LMM o de sucedáneos (LMS. Materiales y métodos. El estudio fue descriptivo, analítico, y observacional, tipo cohorte; se adelantó por dos meses y medio, entre el 31 de agosto y el 27 de septiembre del año 2007 en la consulta externa de niño sano del Hospital Roosevelt. Se enroló a 48 pacientes. Se les tomó las medidas antropométricas de peso y talla, y se siguieron por el período necesario para que alcanzaran un peso de 2,5kg. Resultados. La mayoría pesaron entre 1.000 y 1.500g al nacer. La media de ganancia diaria de peso de los que recibían LME fue de 32,4+9,2g, de LMM fue de 32+7g y de sucedáneos fue de 36,2+7,3g. Comparando la media de ganancia de peso de todos los grupos, se encontró que no existía diferencia estadísticamente significativa (p=0,32, al igual que la ganancia diaria de talla (p=0,44. Conclusiones. Cínicamente, se evidenció que se obtienen ganancias de peso y talla adecuadas en bebés prematuros utilizando LME comparables a las obtenidas utilizando lactancia mixta y sucedáneos.

  11. Concentraciones séricas de triyodotironina, tiroxina y perfil lipídico en bovinos lecheros alimentados con una ración con bajo contenido de selenio Serum concentrations of triiodothyronine, thyroxine and lipid profile in dairy cows fed with a low selenium diet

    OpenAIRE

    R. MATAMOROS; Ceballos, A; PA Contreras; Quiroga, C.; M Andaur; F. WITTWER

    2008-01-01

    El objetivo de este estudio fue evaluar el efecto de un bajo consumo de Se y su suplementación sobre la concentración sérica de T3 y T4 y sobre el perfil lipídico en vacas lactantes bajo estrés oxidativo inducido. Fueron seleccionadas 12 vacas Frisón Negro gestantes, asignadas auno de dos grupos homogéneos, control (n = 6, Se-D) y tratado (n = 6, Se-S) con selenato de bario (BaSe0(4)), ambos recibieron una ración Se-deficiente (el Se en base seca fue 0,03 ppm para la dieta preparto y 0,05 ppm...

  12. OPTIMIZACION DE LA SINTESIS DE GALACTO-OLIGOSACARIDOS EN MODALIDAD DE LOTE ALIMENTADO

    OpenAIRE

    Vera, Carlos

    2012-01-01

    Esta tesis doctoral tiene por hipótesis que la implementación de la síntesis de galacto-oligosacáridos (GOS) en modalidad de lote alimentado y su optimización por metodologías de control óptimo permitirá un aumento de la concentración de GOS en el producto de la reacción, lo cual provocará una mejora en la economía del proceso evaluada en términos de su valor actual neto, respecto de la síntesis por lotes. Con el fin de verificar la hipótesis de esta tesis doctoral, la investigación se lle...

  13. Concentraciones séricas de triyodotironina, tiroxina y perfil lipídico en bovinos lecheros alimentados con una ración con bajo contenido de selenio Serum concentrations of triiodothyronine, thyroxine and lipid profile in dairy cows fed with a low selenium diet

    Directory of Open Access Journals (Sweden)

    R Matamoros

    2008-01-01

    Full Text Available El objetivo de este estudio fue evaluar el efecto de un bajo consumo de Se y su suplementación sobre la concentración sérica de T3 y T4 y sobre el perfil lipídico en vacas lactantes bajo estrés oxidativo inducido. Fueron seleccionadas 12 vacas Frisón Negro gestantes, asignadas auno de dos grupos homogéneos, control (n = 6, Se-D y tratado (n = 6, Se-S con selenato de bario (BaSe0(4, ambos recibieron una ración Se-deficiente (el Se en base seca fue 0,03 ppm para la dieta preparto y 0,05 ppm para la dieta posparto y sebo oxidado (0,5 kg/vaca/día. El grupo Se-S se suplemento con (1 mg Se/kg bajo la forma de BaSe0(4 (1 mL/50 kg, s.c. Previo a la suplementación y cada 15 días, se tomaron muestras de sangre heparinizada y sin anticoagulante mediante venopunción coccígea. Se evaluó la actividad de glutatión peroxidasa (GSH-Px, EC 1.15.1.9, además la concentración sérica de T3 y T4, colesterol total, lipoproteínas (HDL, LDL y VLDL y triacilgliceroles (TAG. La significancia se estableció empleando un PROC MIXED de S AS mediante la opción REPEATED, considerándose significativo P 0,05, y la actividad de GSH-Px aumentó significativamente en el grupo Se-S a partir de 45 días postsuplementación (P 0,05. La concentración de colesterol, LDL, VLDL y TAG fue similar entre los grupos (P > 0,05, siendo la concentración de HDL levemente mayor en el grupo Se-D (P = 0,047. Los resultados permiten señalar que una dieta baja en Se no indujo cambios en la función tiroidea o en el metabolismo de las lipoproteínas, excepto una mayor concentración de HDL, lo que en el bovino requiere la realización de estudios posterioresThe aim of this study was to evaluate the effect of a low Selenium diet and its supplementation on the serum levels of T3, T4 and on the lipid profile in dairy cows under an induced oxidative stress. Twelve pregnant dairy Chilean-Friesian cows were selected and assigned to one of two groups, control (n = 6, Se-D and treated (n

  14. Food commodities from microalgae.

    Science.gov (United States)

    Draaisma, René B; Wijffels, René H; Slegers, P M Ellen; Brentner, Laura B; Roy, Adip; Barbosa, Maria J

    2013-04-01

    The prospect of sustainable production of food ingredients from photoautotrophic microalgae was reviewed. Clearly, there is scope for microalgal oils to replace functions of major vegetable oils, and in addition to deliver health benefits to food products. Furthermore, with a limited production surface, a substantial portion of the European Union market could be supplied with edible oils and proteins from microalgae. Yet, before microalgal ingredients can become genuinely sustainable and cost effective alternatives for current food commodities, major breakthroughs in production technology and in biorefinery approaches are required. Moreover, before market introduction, evidence on safety of novel microalgal ingredients, is needed. In general, we conclude that microalgae have a great potential as a sustainable feedstock for food commodities.

  15. Production of biodiesel from microalgae

    Directory of Open Access Journals (Sweden)

    Danilović Bojana R.

    2014-01-01

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

  16. Biotechnological applications of microalgae

    Directory of Open Access Journals (Sweden)

    Wan-Loy Chu

    2012-07-01

    Full Text Available Microalgae are important biologicalresources that have a wide range of biotechnologicalapplications. Due to their high nutritional value,microalgae such as Spirulina and Chlorella are beingmass cultured for health food. A variety of high-valueproducts including polyunsaturated fatty acids (PUFA,pigments such as carotenoids and phycobiliproteins, andbioactive compounds are useful as nutraceuticals andpharmaceuticals, as well as for industrial applications. Interms of environmental biotechnology, microalgae areuseful for bioremediation of agro-industrial wastewater,and as a biological tool for assessment and monitoring ofenvironmental toxicants such as heavy metals, pesticidesand pharmaceuticals. In recent years, microalgae haveattracted much interest due to their potential use asfeedstock for biodiesel production. In Malaysia, therehas been active research on microalgal biotechnologyfor the past 30 years, tapping into the potential of ourrich microalgal resources for high-value products andapplications in wastewater treatment and assessmentof environmental toxicants. A culture collection ofmicroalgae has been established, and this serves asan important resource for microalgal biotechnologyresearch. Microalgal biotechnology should continue tobe regarded as a priority area of research in this country.

  17. Functional ingredients from microalgae

    NARCIS (Netherlands)

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

    2014-01-01

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

  18. Food commodities from microalgae

    NARCIS (Netherlands)

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

    2013-01-01

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

  19. Biofuels from Microalgae

    NARCIS (Netherlands)

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

    2013-01-01

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

  20. Biohydrogen from Microalgae

    Energy Technology Data Exchange (ETDEWEB)

    Dubini, Alexandra; Gonzalez-Ballester, David

    2016-03-01

    This chapter provides an overview of the current state of knowledge of the mechanisms involved in biohydrogen production from microalgae. The known limitations linked to photohydrogen productivity are addressed. Particular attention is given to physiological and molecular strategies to sustain and improve hydrogen production. The impact of different nutrient stresses and the effect of carbon supply on hydrogen production are discussed. The genetic and metabolic engineering approaches for increasing hydrogen production are outlined.

  1. Fuels from microalgae

    Energy Technology Data Exchange (ETDEWEB)

    1989-06-01

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

  2. Assessment of the toxicity of sediment and seawater polluted by the Prestige fuel spill using bioassays with clams (Venerupis pullastra, Tappes decussatus and Venerupis rhomboideus) and the microalga Skeletonema costatum; Evaluacion de la toxicidad de sedimento y agua de mar contaminados por el vertido de fuel del Prestige, mediante el uso de bioensayos con las almejas Venerupis pullastra, Tappes decussatus y Venerupis rhomboideus y la microalga Skeletonema costatum

    Energy Technology Data Exchange (ETDEWEB)

    Marino-Balsa, J.C.; Perez, P.; Estevez-Blanco, P.; Saco-Alvarez, L.; Fernandez, E.; Beiras, R. [Laboratorio de Ecologia Marina LEM, Facultad de Ciencias, Universidad de Vigo, Galicia (Spain)

    2003-03-15

    In this study we present the early monitoring of the pollution caused by the accident of the Prestige tanker off the Galician coast. To evaluate the toxicity of sediment and water exposed to fuel, three kinds of bioassays were carried out using juvenile clams, clam embryos and microalgae. Firstly, the burrowing behavior of Venerupis pullastra and Tappes decussatus in the sediment collected from two beaches of similar characteristics but different pollution conditions, was studied over 24 h. No significant differences were observed between the two sediments. Secondly, embryogenesis success of Venerupis rhomboideus was recorded after incubation in seawater and elutriates obtained from affected areas. In this case, fuel-polluted seawater showed a marked inhibition of embryogenesis, while sediment elutriates showed moderate toxicity. Parallel bioassays with the diatom Skeletonema costatum were carried out using sediment elutriates and filtered seawater from the sampling sites. The response variable measured was the maximum quantum yield of photosynthesis ({phi}{sub p}o) using a Fast Repetition Rate Fluorometer (FRRF). In the first sampling, significant differences were found in the response of S. costatum cultured in the elutriates as compared to the control after 5 h exposure. The results corresponding to the second sampling showed statistically significant lower values of {phi}{sub p}o in the culture incubated in M2 water as compared with the control, indicating that the water-accommodated fraction of fuel at this site was the most toxic. [Spanish] En este estudio presentamos los primeros resultados obtenidos del control de la contaminacion producida por el accidente del petrolero Prestige en la costa de Galicia. Para evaluar la toxicidad del agua y el sedimento expuestos al fuel, se realizaron tres tipos de bioensayos: usando almejas juveniles, embriones de almeja y una microalga. En los primeros, se evaluo el comportamiento de enterramiento de Venerupis pullastra y

  3. Phototrophic pigment production with microalgae

    NARCIS (Netherlands)

    Mulders, K.J.M.

    2014-01-01

    Abstract

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

  4. Crecimiento y supervivencia de crías de pulpo (Octopus maya : alimentados con dietas inertes bajo condiciones de laboratorio en Yucatán, México Growth and survival of larvals of octopus (Octopus maya : fed with inert diets under conditions of laboratory in Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    Miguel Rodríguez-Serna

    2008-12-01

    Full Text Available Bajo un diseño experimental se probaron tres dietas con el objetivo de determinar el crecimiento y la supervivencia de las crías de Octopus maya (Voss y Solís 1966, utilizando dos tipos de alimento inerte (A2 = Balanceado, A3 = Surimi y comparándolo con un alimento vivo (A1 = Artemia, bajo condiciones controladas. Los resultados mostraron diferencias significativas entre el alimento vivo y el alimento inerte. Se encontró un mejor crecimiento en peso ganado en las crías de pulpo alimentadas con una dieta viva en comparación con las dietas inertes (A1 = 11.88 g, A2 = 8.9 g, A3 = 8.83 g; sin embargo, para las tres dietas se obtuvo una baja supervivencia. El análisis estadístico arrojó diferencias estadísticas (p > 0.05 entre todos los tratamientos, siendo el alimento vivo el que presentó la mayor supervivencia con un 61.3%, seguido del surimi con un 42.3% y finalmente el balanceado con un 27.6%. La alimentación de O. maya en cautiverio aún requiere de muchos esfuerzos para desarrollar un alimento balanceado adecuado desde el punto de vista nutrimental o de formulación, así como desde la parte de atracción y aceptación por los animales.Three experimental diets were probed for the growth and survival rates of young Octopus maya (Voss and Solis 1966, using two inert foods (A2 = shrimp pellets, A3 = Surimi and one alive food (A1 = Artemia, under controlled conditions. The results showed significant differences between the live food and the inert ones. Young octopus feed with artemia, reported better growth in weight gained compared with the inert diets (A1 = 11.88 g, A2 = 8.9 g, A3 = 8.83 g. All three diets obtained low survivorships, being the alive food the best one with a rate of 61.3%, followed by surimi with 42.3%, and finally the pellet food with 27.6%. Statistical analysis showed differences (p > 0.05 between all the treatments for both growth and survival results. Artificial feeding of O. maya in captivity still requires many

  5. Management of oxidative stress by microalgae.

    Science.gov (United States)

    Cirulis, Judith T; Scott, J Ashley; Ross, Gregory M

    2013-01-01

    The aim of this review is to provide an overview of the current research on oxidative stress in eukaryotic microalgae and the antioxidant compounds microalgae utilize to control oxidative stress. With the potential to exploit microalgae for the large-scale production of antioxidants, interest in how microalgae manage oxidative stress is growing. Microalgae can experience increased levels of oxidative stress and toxicity as a result of environmental conditions, metals, and chemicals. The defence mechanisms for microalgae include antioxidant enzymes such as superoxide dismutase, catalase, peroxidases, and glutathione reductase, as well as non-enzymatic antioxidant molecules such as phytochelatins, pigments, polysaccharides, and polyphenols. Discussed herein are the 3 areas the literature has focused on, including how conditions stress microalgae and how microalgae respond to oxidative stress by managing reactive oxygen species. The third area is how beneficial microalgae antioxidants are when administered to cancerous mammalian cells or to rodents experiencing oxidative stress.

  6. Cell disruption for microalgae biorefineries.

    Science.gov (United States)

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

    2015-01-01

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

  7. Fuel from microalgae lipid products

    Energy Technology Data Exchange (ETDEWEB)

    Hill, A.M.; Feinberg, D.A.

    1984-04-01

    The large-scale production of microalgae is a promising method of producing a renewable feedstock for a wide variety of fuel products currently refined from crude petroleum. These microalgae-derived products include lipid extraction products (triglycerides, fatty acids, and hydrocarbons) and catalytic conversion products (paraffins and olefins). Microalgal biomass productivity and lipid composition of current experimental systems are estimated at 66.0 metric tons per hectare year and 30% lipid content. Similar yields in a large-scale facility indicate that production costs are approximately six times higher than the average domestic price for crude, well-head petroleum. Based on achievable targets for productivity and production costs, the potential for microalgae as a fuel feedstock is presented in context with selected process refining routes and is compared with conventional and alternative feedstocks (e.g., oilseeds) with which microalgae must compete. 24 references, 9 figures, 4 tables.

  8. Microalgae biofuel potentials (review).

    Science.gov (United States)

    Ghasemi, Y; Rasoul-Amini, S; Naseri, A T; Montazeri-Najafabady, N; Mobasher, M A; Dabbagh, F

    2012-01-01

    With the decrease of fossil based fuels and the environmental impact of them over the planet, it seems necessary to seek the sustainable sources of clean energy. Biofuels, is becoming a worldwide leader in the development of renewable energy resources. It is worthwhile to say that algal biofuel production is thought to help stabilize the concentration of carbon dioxide in the atmosphere and decrease global warming impacts. Also, among algal fuels' attractive characteristics, algal biodiesel is non toxic, with no sulfur, highly biodegradable and relatively harmless to the environment if spilled. Algae are capable of producing in excess of 30 times more oil per acre than corn and soybean crops. Currently, algal biofuel production has not been commercialized due to high costs associated with production, harvesting and oil extraction but the technology is progressing. Extensive research was conducted to determine the utilization of microalgae as an energy source and make algae oil production commercially viable.

  9. [Harvesting microalgae via flocculation: a review].

    Science.gov (United States)

    Wan, Chun; Zhang, Xiaoyue; Zhao, Xinqing; Bai, Fengwu

    2015-02-01

    Microalgae have been identified as promising candidates for biorefinery of value-added molecules. The valuable products from microalgae include polyunsaturated fatty acids and pigments, clean and sustainable energy (e.g. biodiesel). Nevertheless, high cost for microalgae biomass harvesting has restricted the industrial application of microalgae. Flocculation, compared with other microalgae harvesting methods, has distinguished itself as a promising method with low cost and easy operation. Here, we reviewed the methods of microalgae harvesting using flocculation, including chemical flocculation, physical flocculation and biological flocculation, and the progress and prospect in bio-flocculation are especially focused. Harvesting microalgae via bio-flocculation, especially using bio-flocculant and microalgal strains that is self-flocculated, is one of the eco-friendly, cost-effective and efficient microalgae harvesting methods.

  10. Phosphopantetheinylation in the green microalgae Chlamydomonas reinhardtii

    DEFF Research Database (Denmark)

    Sonnenschein, Eva; Pu, Yuan; Beld, Joris

    2016-01-01

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

  11. New challenges in microalgae biotechnology.

    Science.gov (United States)

    Valverde, Federico; Romero-Campero, Francisco J; León, Rosa; Guerrero, Miguel G; Serrano, Aurelio

    2016-08-01

    Photosynthetic protists, also called microalgae, have been systematically studied for more than a century. However, only recently broad biotechnological applications have fostered a novel wave of research on their potentialities as sustainable resources of renewable energy as well as valuable industrial and agro-food products. At the recent VII European Congress of Protistology held in Seville, three outstanding examples of different research strategies on microalgae with biotechnological implications were presented, which suggested that integrative approaches will produce very significant advances in this field in the next future. In any case, intense research and the application of systems biology and genetic engineering techniques are absolutely essential to reach the full potential of microalgae as cell-factories of bio-based products and, therefore, could contribute significantly to solve the problems of biosustainability and energy shortage.

  12. Flashing light in microalgae biotechnology.

    Science.gov (United States)

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

    2016-03-01

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

  13. Efecto de la alimentación con sangre humana sobre la fecundidad, fertilidad y ciclo biológico de Rhodnius prolixus (Hemiptera: Reduviidae)

    OpenAIRE

    2014-01-01

    Se observó el efecto de diferentes fracciones de sangre humana sobre la ovipostura (fecundidad), la eclosión (fertilidad) y el ciclo biológico de Rhodnius prolixus Stal 1859 utilizando un alimentador artificial. En los ejemplares alimentados con sangre de hombre, la fecundidad fue mayor que en los alimentados con sangre de mujer. No hubo diferencia significativa en la fertilidad relacionada con la procedencia de las fracciones. En cada estadio se estimaron los tiempos de permanencia y el núme...

  14. Desempenho produtivo de cabritos alimentados com glicerina bruta

    Directory of Open Access Journals (Sweden)

    Diego Amorim dos Santos

    2015-04-01

    Full Text Available Avaliou-se o desempenho produtivo de cabritos mestiços terminados em confinamento, alimentados com dietas contendo glicerina bruta (0, 4, 8 e 12% na MS. Vinte cabritos mestiços foram utilizados em blocos completos, casualizados com quatro tratamentos e cinco repetições, para determinação do ganho médio diário (GMD, consumo de matéria seca (CMS e nutrientes (PB, FDN, EE e comportamento ingestivo. Para o ensaio de digestibilidade, foram utilizados quatro caprinos alocados em delineamento em quadrado latino, para determinação da digestibilidade da MS e nutrientes (PB, FDN, EE. A adição de glicerina bruta não interferiu (P>0,05 no GMD e no CMS e demais nutrientes. O tempo de ingestão aumentou com o incremento de glicerina bruta nas dietas. Não houve diferença significativa (P>0,05 dos tratamentos sobre o tempo gasto na ruminação e digestibilidade da MS, PB e FDN, contudo, houve efeito quadrático para a digestibilidade do EE. Recomenda-se a inclusão em até 12% de glicerina bruta para cabritos em terminação, em situações de oscilação do preço do milho, sem alteração nos parâmetros produtivos avaliados

  15. Cell disruption for microalgae biorefineries

    NARCIS (Netherlands)

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

    2015-01-01

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

  16. Circadian rhythms in microalgae production

    NARCIS (Netherlands)

    Winter, de L.

    2015-01-01

    Abstract Thesis: Circadian rhythms in microalgae production Lenneke de Winter The sun imposes a daily cycle of light and dark on nearly all organisms. The circadian clock evolved to help organisms program their activities at an appropriate time during this daily cycle. For example,

  17. Current Status and Prospects of Biodiesel Production from Microalgae

    Directory of Open Access Journals (Sweden)

    Yuhuan Liu

    2012-07-01

    Full Text Available Microalgae represent a sustainable energy source because of their high biomass productivity and ability to remove air and water born pollutants. This paper reviews the current status of production and conversion of microalgae, including the advantages of microalgae biodiesel, high density cultivation of microalgae, high-lipid content microalgae selection and metabolic control, and innovative harvesting and processing technologies. The key barriers to commercial production of microalgae biodiesel and future perspective of the technologies are also discussed.

  18. Current Status and Prospects of Biodiesel Production from Microalgae

    OpenAIRE

    2012-01-01

    Microalgae represent a sustainable energy source because of their high biomass productivity and ability to remove air and water born pollutants. This paper reviews the current status of production and conversion of microalgae, including the advantages of microalgae biodiesel, high density cultivation of microalgae, high-lipid content microalgae selection and metabolic control, and innovative harvesting and processing technologies. The key barriers to commercial production of microalgae biodie...

  19. Microalgae biorefinery: High value products perspectives.

    Science.gov (United States)

    Chew, Kit Wayne; Yap, Jing Ying; Show, Pau Loke; Suan, Ng Hui; Juan, Joon Ching; Ling, Tau Chuan; Lee, Duu-Jong; Chang, Jo-Shu

    2017-04-01

    Microalgae have received much interest as a biofuel feedstock in response to the uprising energy crisis, climate change and depletion of natural sources. Development of microalgal biofuels from microalgae does not satisfy the economic feasibility of overwhelming capital investments and operations. Hence, high-value co-products have been produced through the extraction of a fraction of algae to improve the economics of a microalgae biorefinery. Examples of these high-value products are pigments, proteins, lipids, carbohydrates, vitamins and anti-oxidants, with applications in cosmetics, nutritional and pharmaceuticals industries. To promote the sustainability of this process, an innovative microalgae biorefinery structure is implemented through the production of multiple products in the form of high value products and biofuel. This review presents the current challenges in the extraction of high value products from microalgae and its integration in the biorefinery. The economic potential assessment of microalgae biorefinery was evaluated to highlight the feasibility of the process.

  20. Optimization of Biofuel Production From Transgenic Microalgae

    Science.gov (United States)

    2013-02-27

    AFRL-OSR-VA-TR-2013-0145 OPTIMIZATION OF BIOFUEL PRODUCTION FROM TRANSGENIC MICROALGAE Richard Sayre Donald Danforth...Technical 20080815 to 20120630 OPTIMIZATION OF BIOFUEL PRODUCTION FROM TRANSGENIC MICROALGAE FA9550-08-1-0451 Richard Sayre Donald Danforth Plant...BIOFUEL PRODUCTION FROM TRANSGENIC MICROALGAE Grant/Contract Number: FA9550-08-1-0451 Reporting Period: Final Report Abstract: We have compared the

  1. Global evaluation of biofuel potential from microalgae

    OpenAIRE

    2014-01-01

    Research into microalgae as a feedstock for biofuels continues to increase because of the inherent potential advantages it holds over traditional terrestrial feedstocks. However, the true near-term large-scale productivity of microalgae remains uncertain. This study integrates a large-scale, outdoor growth model with historical meteorological data from 4,388 global locations to estimate the current near-term lipid and biomass productivity potential from microalgae cultivated in a photobioreac...

  2. Morphology of photoreceptor systems in microalgae.

    Science.gov (United States)

    Gualtieri, P

    2001-06-01

    The polyphyletic artificial assemblage of O(2)-evolving, photosynthetic organisms, collectively referred to as algae, include a highly diverse array of organisms from large seaweeds (macroalgae) to unicellular microalgae. Phycology, the study of algae, focuses on morphological, ecological, physiological and molecular biological aspects of these organisms. Most microalgae show a photo-behaviour, i.e. they sense light and move towards it; in this review we will describe morphological similarities and differences in the photoreceptive system of microalgae.

  3. Microalgae Culture Collection: 1984-1985

    Energy Technology Data Exchange (ETDEWEB)

    1984-09-01

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

  4. Efecto de diferentes dietas de microalgas sobre la supervivenci y crecimiento de Apocyclops aff. panamensis (Marsh, 1913 (Copépodo: Cyclopoida cultivado bajo condiciones controladas de laboratorio - Effect of different diets from microalga on supervivenci and growth of Apocyclops aff. panamensis (Marsh, 1913 (Copépodo: Cyclopoida cultivated under controlled conditions of laboratory

    Directory of Open Access Journals (Sweden)

    Elifonso Isiordia Perez,

    2006-07-01

    Full Text Available El presente trabajo fue realizado Julio 2001 con el propósito de evaluar el efecto de diferentes dietas de microalgas sobre la supervivencia y crecimiento (desarrollo de Apocyclops aff. Panamensis. El experimento duró 15 días y se realizó en las instalaciones del Instituto de Ciencias del Mar y Limnología (UNAM Unidad académica Mazatlán Sinaloa. El sistema consistió en un acuario de fibra de vidrio (50x30x40 al cual se agregó 4 litros de agua dulce filtrada 5µ se colocó un termostato para presentar condiciones controladas de temperatura (28ºC, así mismo se mantuvo constante el fotoperiodo (8 horas luz. En el interior del acuario se colocó 1 gradilla con 35 tubos de ensayo con 6 ml de agua salada a 32 ‰ filtrada con luz ultravioleta. Los copépodos fueron colectados en la boca del estero el Yugo Mazatlán, Sinaloa, transportados y aclimatados durante 15 minutos. La siembra consistió en colocar 20 nauplios en estadio II en cada tubo de ensayo. Los tratamientos que se aplicaron como alimento fueron: Chaetoceros sp. + Nannocloropsis sp. (50%:50% (T1, Isochrysis sp. + Nannocloropsis sp. (50%:50% (T2, Chaetoceros sp. + Isochrysis sp. (50%:50% (T3, Chaetoceros sp. (100% (T4, Isochrysis sp. (100% (T5, Nannocloropsis sp. (100% (T6, Chaetoceros sp. + Isochrysis sp. + Nannocloropsis sp. (1:1:1 (T7 cada uno con 5 repeticiones. La densidad de microalgas a suministrar para el presente experimento fue de 50,000 células / mililitro. Al finalizar el estudio solo los copépodos que lograron una supervivencia del 15% hasta copepodito 5 fueron los alimentados con Nanocloropsis sp. (100% y la mayor longitud (0.83 mm se presentó en copépodos alimentados con Chaetoceros sp. (100%, De acuerdo a los resultados se concluye que para lograr mayor crecimiento y supervivencia en el cultivo de copépodos Apocyclops aff. Panamensis se recomienda usar estos tratamientos como alimento. The present work was made July 2001 in order to evaluate the effect of

  5. Microalgae production in a biofilm photobioreactor

    NARCIS (Netherlands)

    Blanken, Ward

    2016-01-01

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

  6. Mechanism behind autoflocculation of unicellular green microalgae

    NARCIS (Netherlands)

    Salim, S.; Kosterink, N.; Tchetkoua Wacka, N.D.; Vermue, M.H.; Wijffels, R.H.

    2014-01-01

    The oleaginous Ettlia texensis is an autoflocculating green microalga that can be used for bio-flocculation of other microalgae species to facilitate harvesting. In this study the mechanism behind autoflocculation of E. texensis was revealed by scanning electron microscopy (SEM) analysis and by char

  7. Production of biofuels obtained from microalgae

    Directory of Open Access Journals (Sweden)

    Luis Carlos Fernández-Linares

    2012-09-01

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

  8. Application of photobioreactors to cultivation of microalgae

    Institute of Scientific and Technical Information of China (English)

    陈雷; 王光玉

    2003-01-01

    An overview of photobioreactors now in use for production of microalgae world wide is presented, andthe application of photobioreactors to the cultivation of microalgae is discussed in detail. It is pointed out thathigh cell density and industrial production of microalgae can be achieved using many kinds of closed photobiore-actors including fermentor, tubular and flat plate photobioreactors, and the cultivation of Spirulina, Chlorella,Dunaliella tertiolecta and Porphyridium cruentrim by photobioreactors can achieve higher and steadier produc-tivity than the cultivation of microalgae by an open air system. More and more researches indicate that tubularand flat plate photobioreactors are the development trend for photobioreactors with bubbles and air lift stirrers,and high bright light-emitting diodes are the most economic light source with great potential for future develop-ment of photobioreactors. Photobioreactors can also be used for the production of high-value metabolite ( EPA orDHA) using some microalgae species for energy development and environment protection.

  9. Astaxanthin production by freshwater microalgae Chlorella sorokiniana and marine microalgae Tetraselmis sp.

    Science.gov (United States)

    Raman, Rinugah; Mohamad, Shaza Eva

    2012-12-15

    There are numerous commercial applications of microalgae nowadays owing to their vast biotechnological and economical potential. Indisputably, astaxanthin is one of the high value product synthesized by microalgae and is achieving commercial success. Astaxanthin is a keto-carotenoid pigment found in many aquatic animals including microalgae. Astaxanthin cannot be synthesized by animals and provided in the diet is compulsory. In this study, the production of astaxanthin by the freshwater microalgae Chlorella sorokiniana and marine microalgae Tetraselmis sp. were studied. The relationship between growth and astaxanthin production by marine and freshwater microalgae cultivated under various carbon sources and concentrations, environmental conditions and nitrate concentrations was investigated in this study. Inorganic carbon source and low nitrate concentration favored the growth and production of astaxanthin by the marine microalgae Tetraselmis sp. and the freshwater microalgae Chlorella sorokiniana. Outdoor cultivation enhanced the growth of microalgae, while indoor cultivation promoted the formation of astaxanthin. The results indicated that supplementation of light, inorganic carbon and nitrate could be effectively manipulated to enhance the production of astaxanthin by both microalgae studied.

  10. Meta-análisis de dietas con baja proteína adicionadas con aminoácidos sintéticos para cerdos en engorda.

    OpenAIRE

    González Reyes, Mónica

    2013-01-01

    Se han reportado resultados inconsistentes utilizando dietas bajas en proteína cruda formuladas con sorgo-pasta de soya adicionadas con AA sintéticos que mantengan los resultados productivos y las características de la canal de cerdos alimentados con dieta estándar. Esto ha motivado a realizar un meta-análisis para combinar los resultados originales de estudios independientes. El conjunto de datos utilizados se basó en una línea de investigación sobre la alimentación de cerdos con dietas baja...

  11. Effective flocculation of target microalgae with self-flocculating microalgae induced by pH decrease.

    Science.gov (United States)

    Liu, Jiexia; Tao, Yujun; Wu, Jinheng; Zhu, Yi; Gao, Baoyan; Tang, Yu; Li, Aifen; Zhang, Chengwu; Zhang, Yuanming

    2014-09-01

    A flocculation method was developed to harvest target microalgae with self-flocculating microalgae induced by decreasing pH to just below isoelectric point. The flocculation efficiencies of target microalgae were much higher than those flocculated only via pH decrease. The mechanism could be that negatively charged self-flocculating microalgal cells became positively charged during pH decrease, subsequently attracted negatively charged target microalgae cells to form flocs and settled down due to gravity. Microalgal biomass concentration and released polysaccharide (RPS) from target microalgae influenced flocculation efficiencies, while multivalent metal ions in growth medium could not. Furthermore, neutralizing pH and then supplementing nutrients allowed flocculated medium to be recycled for cultivation. Finally, Spearman's Rank Correlation Coefficients (Rs) between flocculation efficiency and key factors were also investigated. These results suggest that this method is effective, simple to operate and allows the reuse of flocculated medium, thereby contributing to the economic production from microalgae to biodiesel.

  12. Feasibility of remote sensing benthic microalgae

    Science.gov (United States)

    Zingmark, R. G.

    1979-01-01

    Results of data analyses from multispectral scanning data are presented. The data was collected in July 1977 for concentration of chlorophyll in benthic microalgae (mainly diatoms) on an estuary mudflat.

  13. Screening of antioxidant activity in microalgae

    Directory of Open Access Journals (Sweden)

    Mariana F.G. Assunção

    2014-06-01

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

  14. Biologically Active Metabolites Synthesized by Microalgae

    Directory of Open Access Journals (Sweden)

    Michele Greque de Morais

    2015-01-01

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

  15. TAXAS DE FILTRAÇÃO E INGESTÃO DE UMA MICROALGA POR Philodina roseola (Rotifera: Bdelloidea

    Directory of Open Access Journals (Sweden)

    Raquel Aparecida Moreira

    2016-04-01

    Full Text Available RESUMORotíferos possuem um importante papel nos ciclos biogeoquímicos e na produtividade orgânica dos ecossistemas de água doce em decorrência de suas elevadas taxas metabólicas. Informações sobre a filtração, seu principal processo de aquisição de energia, são relevantes e ainda escassos para a região tropical. Os rotíferos da Subclasse Bdelloidea alimentam-se por filtração ou raspagem consumindo pequenos itens alimentares, como bactérias, algas, leveduras ou matéria orgânica particulada. Sabemos pouco sobre o papel que desempenham na dinâmica trófica dos habitats que ocupam e por isso o objetivo deste estudo foi quantificar em laboratório as taxas de filtração e ingestão do rotífero Philodina roseola, alimentado com Raphidocelis subcapitata. O delineamento experimental consistiu na exposição de 10 rotíferos adultos por tratamento, em cinco concentrações que variaram entre 104 e 107 cels mL-1, mantidos sob temperatura de 25 ± 1 °C. Os experimentos tiveram a duração de 1 hora e as concentrações iniciais e finais da suspensão algal foram quantificadas por contagem numérica das células em câmara de Neubauer. Não foram encontradas diferenças significativas entre as concentrações iniciais e finais de células nos controles indicando não ter ocorrido crescimento algal. As taxas de filtração de P. roseola variaram entre 0,09 e 0,25 mL ind-1 h-1. Tendo em vista que a filtração é o principal processo de aquisição de energia de Philodina roseola, assim como dos demais rotíferos, e que está relacionada a questões importantes da dinâmica trófica dos ecossistemas aquáticos, informações adicionais são desejáveis mas necessitam, no entanto, ser ampliadas para outros tipos de alimento e para diferentes combinações de condições experimentais.Rates of Filtration and Ingestion of a Microalga by Philodina roseola (Rotifera: BdelloideaABSTRACTRotifers play an important role in biogeochemical cycles

  16. Experimentacion y optimizacion conjunta de la disrupcion celular de microalgas y extraccion soxhletde aceite para alimentacion y biocombustibles

    OpenAIRE

    2014-01-01

    La producción de biocombustibles y bioproductos utilizando microalgas puede realizarse con tratamientos térmicos para producir biocrudo, o mediante la extracción y transformación de metabolitos específicos. Esta última alternativa incluye las etapas de cultivo, cosecha, secado, extracción de lípidos y purificación o transformación de los mismos. La factibilidad técnica y económica de la obtención de bioproductos derivados del aceite de microalgas depende en gran medida de la eficiencia de ext...

  17. RESPUESTA ANTAGÓNICA DE MICROORGANISMOS AISLADOS DE LOS CULTIVOS DE MICROALGAS EN EL LABORATORIO DE CULTIVOS MARINOS

    Directory of Open Access Journals (Sweden)

    Carmen Ruíz Huamán

    2013-10-01

    Full Text Available Durante el 2012, el Laboratorio de Cultivos Marinos obtuvo bacterias aisladas de los cultivos de microalgas. Se trabajó 60 colonias de los cultivos. Se confrontó una a una las colonias aisladas del cultivo de microalgas con las bacterias patógenas tipo ATCC, estas fueron: Flavobacterium psychrophilum, Aeromona hydrophila, Lactococcus garviaceae y Vibrio herveyi. Solo una bacteria tuvo interacción antagónica ya que formó el halo de inhibición.

  18. Harvesting microalgae grown on wastewater.

    Science.gov (United States)

    Udom, Innocent; Zaribaf, Behnaz H; Halfhide, Trina; Gillie, Benjamin; Dalrymple, Omatoyo; Zhang, Qiong; Ergas, Sarina J

    2013-07-01

    The costs and life cycle impacts of microalgae harvesting for biofuel production were investigated. Algae were grown in semi-continuous culture in pilot-scale photobioreactors under natural light with anaerobic digester centrate as the feed source. Algae suspensions were collected and the optimal coagulant dosages for metal salts (alum, ferric chloride), cationic polymer (Zetag 8819), anionic polymer (E-38) and natural coagulants (Moringa Oleifera and Opuntia ficus-indica cactus) were determined using jar tests. The relative dewaterability of the algae cake was estimated by centrifugation. Alum, ferric chloride and cationic polymer could all achieve >91% algae recovery at optimal dosages. Life cycle assessment (LCA) and cost analysis results revealed that cationic polymer had the lowest cost but the highest environmental impacts, while ferric chloride had the highest cost and lowest environmental impacts. Based on the LCA results, belt presses are the recommended algae dewatering technology prior to oil extraction.

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

    NARCIS (Netherlands)

    Garcia Alba, Laura; Torri, Cristian; Fabbri, Daniele; Kersten, Sascha R.A.; Brilman, Derk W.F. (Wim)

    2013-01-01

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

  20. Bioremediation of wastewater using microalgae

    Science.gov (United States)

    Chalivendra, Saikumar

    Population expansion and industrial development has deteriorated the quality of freshwater reservoirs around the world and has caused freshwater shortages in certain areas. Discharge of industrial effluents containing toxic heavy metals such as Cd and Cr into the environment have serious impact on human, animal and aquatic life. In order to solve these problems, the present study was focused on evaluating and demonstrating potential of microalgae for bioremediation of wastewater laden with nitrogen (N) in the form of nitrates, phosphorous (P) in the form of phosphates, chromium (Cr (VI)) and cadmium (Cd (II)). After screening several microalgae, Chlorella vulgaris and algae taken from Pleasant Hill Lake were chosen as candidate species for this study. The viability of the process was demonstrated in laboratory bioreactors and various experimental parameters such as contact time, initial metal concentration, algae concentration, pH and temperature that would affect remediation rates were studied. Based on the experimental results, correlations were developed to enable customizing and designing a commercial Algae based Wastewater Treatment System (AWTS). A commercial AWTS system that can be easily customized and is suitable for integration into existing wastewater treatment facilities was developed, and capital cost estimates for system including installation and annual operating costs were determined. The work concludes that algal bioremediation is a viable alternate technology for treating wastewater in an economical and sustainable way when compared to conventional treatment processes. The annual wastewater treatment cost to remove N,P is ~26x lower and to remove Cr, Cd is 7x lower than conventional treatment processes. The cost benefit analysis performed shows that if this technology is implemented at industrial complexes, Air Force freight and other Department of Defense installations with wastewater treatment plants, it could lead to millions of dollars in

  1. Lutein production from biomass: marigold flowers versus microalgae.

    Science.gov (United States)

    Lin, Jian-Hao; Lee, Duu-Jong; Chang, Jo-Shu

    2015-05-01

    Microalgae have faster growth rates and more free lutein than marigold flowers, the current source of lutein. However, no commercial lutein production uses microalgae. This review compares lutein content, cultivation, harvesting, cell disruption, and extraction stages of lutein production using marigold flowers and those using microalgae as feedstock. The lutein production rate of microalgae is 3-6 times higher than that of marigold flowers. To produce 1 kg of pure lutein, marigolds need more land and water, but require less nutrients (N, P, K) and less energy than microalgae. Since lutein is tightly bound in microalgae and microalgae are small, cell disruption and subsequent extraction stages consume a considerable amount of energy. Research and development of affordable lutein production from microalgae are discussed.

  2. Harvesting microalgae by bio-flocculation and autoflocculation

    OpenAIRE

    2013-01-01

    Harvesting in commercial microalgae production plants is generally done by centrifugation, but this requires upto about 50% of the total energy gained from the microalgae. The energy needed for harvesting can be reduced considerably by pre-concentration of the microalgae prior to further dewatering. The focus of this thesis was on development of a controlled pre-concentration step in which bio-flocculation and autoflocculation using oleaginous microalgae is applied combined with gravity sedim...

  3. The Potential for Microalgae as Bioreactors to Produce Pharmaceuticals

    OpenAIRE

    2016-01-01

    As photosynthetic organisms, microalgae can efficiently convert solar energy into biomass. Microalgae are currently used as an important source of valuable natural biologically active molecules, such as carotenoids, chlorophyll, long-chain polyunsaturated fatty acids, phycobiliproteins, carotenoids and enzymes. Significant advances have been achieved in microalgae biotechnology over the last decade, and the use of microalgae as bioreactors for expressing recombinant proteins is receiving incr...

  4. Harvesting microalgae by bio-flocculation and autoflocculation

    NARCIS (Netherlands)

    Salim, S.

    2013-01-01

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

  5. Microalgae bulk growth model with application to industrial scale systems

    NARCIS (Netherlands)

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

    2011-01-01

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

  6. Calidad y rendimiento en canal de corderos en pastoreo suplementados con caña de azúcar fermentada

    Directory of Open Access Journals (Sweden)

    J. C. Frías

    2011-01-01

    Full Text Available El objetivo del trabajo fue medir el rendimiento de la canal y la calidad de la carne de corderos alimentados con pasto, suplementados con caña de azúcar fermentada en forma aeróbica. Se llevó a cabo en dos sitios. Se trabajó con un grupo de 13 corderos de 11.5 kg de peso vivo inicial, estabulados y alimentados con pasto, suplementados con caña de azúcar fermentada en Cunduacán, Tabasco, y 24 corderos con 20 kg de peso vivo inicial, semiestabulado en pastoreo con pasto Estrella Africana, suplementados con caña de azúcar fermentada, en Huimanguillo, Tabasco. Se sacrificaron a un peso de 32 kg. Los resultados fueron analizados mediante estadística descriptiva. La ganancia diaria de peso fue de 109 y 85 g para el sistema Cunduacán y Huimanguillo, respectivamente. El peso y rendimiento de la canal en frío y caliente fue de 13.5 y de 14.14 kg, 42.04 y 43.09% y 40.28 y 41.45%, para el sistema Cunduacán y Huimanguillo, respectivamente. La relación entre el peso al sacrificio con el rendimiento de la canal tuvo correlación negativa de -0.41. Las piezas de mayor peso fueron, pierna, costilla/falda, lomo y paleta. La capacidad de retención de agua fue 12.78, 12.8, y elpH, 5.49 y 5.71, para el sistema Cunduacán y Huimanguillo, respectivamente. El color de la grasa fue blanco para las canales de ovinos, en ambos sitios. Se concluye que los corderos de pelo alimentados con pasto y caña fermentada producen canales con bajo rendimiento magro y con grasa de color blanca.

  7. ESTUDO BIOMÉTRICO DE RATOS ALIMENTADOS COM DOIS TIPOS DE DIETA

    OpenAIRE

    Alice Cristina Antonio dos Santos; Ana Carolina Tocilo Lopes; Gláucia de Cássia Xavier da Cruz; Bruna Corral Garcia; Fábio Yoshikazu Kodama; Regina Celi Trindade Camargo; José Carlos Silva Camargo Filho

    2010-01-01

    A dieta hipercalórica é tida como fator de risco para o desenvolvimento de doenças cardiovasculares, sendo preocupante para a saúde pública mundial. O objetivo do presente estudo foi comparar a biometria de ratos alimentados por dois tipos de dieta. Para tanto, foram utilizados 24 ratos Wistar machos com 90 dias com oferta de ração e água à vontade; divididos em G1 recebendo dieta normocalórica e G2, dieta hipercalórica. A ingesta alimentar foi mensurada diariamente. Após 18 semanas foram eut...

  8. Availability and Utilization of Pigments from Microalgae.

    Science.gov (United States)

    Begum, Hasina; Yusoff, Fatimah Md; Banerjee, Sanjoy; Khatoon, Helena; Shariff, Mohamed

    2016-10-02

    Microalgae are the major photosynthesizers on earth and produce important pigments that include chlorophyll a, b and c, β-carotene, astaxanthin, xanthophylls, and phycobiliproteins. Presently, synthetic colorants are used in food, cosmetic, nutraceutical, and pharmaceutical industries. However, due to problems associated with the harmful effects of synthetic colorants, exploitation of microalgal pigments as a source of natural colors becomes an attractive option. There are various factors such as nutrient availability, salinity, pH, temperature, light wavelength, and light intensity that affect pigment production in microalgae. This paper reviews the availability and characteristics of microalgal pigments, factors affecting pigment production, and the application of pigments produced from microalgae. The potential of microalgal pigments as a source of natural colors is enormous as an alternative to synthetic coloring agents, which has limited applications due to regulatory practice for health reasons.

  9. Ultrasonic cavitation for disruption of microalgae.

    Science.gov (United States)

    Greenly, Justin M; Tester, Jefferson W

    2015-05-01

    Challenges with mid-stream fractionation steps in proposed microalgae biofuel pathways arise from the typically dilute cell density in growth media, micron scale cell sizes, and often durable cell walls. For microalgae to be a sustainable source of biofuels and co-products, efficient fractionation by some method will be necessary. This study evaluates ultrasonic cell disruption as a processing step that fractionates microalgae. A range of species types with different sizes and cell wall compositions were treated. The initial seconds of sonication offered the most significant disruption, even for the more durable Nannochloropsis cells. Following this initial period, diminishing effectiveness was attributed, by acoustic measurements, to attenuation of the ultrasound in the ensuing cloud of cavitating bubbles. At longer exposure times, differences between species were more pronounced. Processing higher concentrations of Isochrysis slowed cell disintegration only marginally, making the expenditure of energy more worthwhile.

  10. Physico-chemical surface properties of microalgae.

    Science.gov (United States)

    Ozkan, Altan; Berberoglu, Halil

    2013-12-01

    This study reports a comprehensive set of experimentally measured physico-chemical surface properties of 12 different microalgae including fresh and seawater species of green algae, diatoms and cyanobacteria. The surface free energy and its components including the acid-base (AB), van der Waals (LW), electron donor/acceptor parameters were quantified based on contact angle measurements along with the Lifshitz-van der Waals acid-base approach using the probe liquid surface tension parameters proposed by van Oss et al. as well as by Della Volpe and Siboni. Moreover, the zeta and surface potentials of all species were determined using electrophoretic mobility measurements along with using Smoluchowski's model. Finally, the free energy of cohesion of the microalgae was also determined based on the calculated surface energy properties. The results showed that the electron donor parameter correlated well with the free energy of cohesion in all groups of microalgae. Moreover, species known to form colonies and exhibit benthic cultures had distinctly hydrophobic surfaces compared to microalgae prefering planktonic growth. These results indicate the importance of surface hydrophobicity for causing biofouiling or flocculation of cultures. Finally, the zeta potentials did not show a distinctive trend with the types of microalgae but the surface potentials were markedly larger for the salt water species. The reported methods and data are expected to provide critical information for researchers and technology developers concerned with cell to cell and cell to substrata interactions of microalgae in algal biomass cultivation and harvesting, biofouling of membranes and surfaces, as well as cell-surface interactions in photosynthetic microbial fuel cell technologies.

  11. Potential of microalgae and cyanobacteria in bioremediation of distillery wastewaters

    Directory of Open Access Journals (Sweden)

    Isis Amores-Sanchez

    2015-01-01

    Full Text Available Los efluentes de destilerías, también llamados vinazas, son unos de los residuales más agresivos para el medio ambiente. Muchos estudios han focalizado los biotratamientos al uso de hongos y bacterias, pero la descontaminación eficiente de dicho efluente es todavía un problema sin resolver. En los últimos tiempos microalgas y cianobacterias han surgido como una alternativa muy promisoria a la destoxificación. Estos microorganismo ofrecen una serie de ventajas como son: la degradación de gran cantidad de contaminantes, síntesis de metabolitos con alto valor agregado, utilización de una fuente de energía abundante y barata (Luz solar, utilización de su biomasa para la producción de una gran variedad de compuestos con aplicaciones en la industria química y farmaceútica entre otras. En esta revisión abordamos el potencial de estos microorganismos para tratar sustancias contaminantes estructuralmente relacionadas con las vinazas, su capacidad para metabolizar compuestos fenolicos como lignina y taninos así como la degradación de las melanoidinas, compuesto recalcitrante presente en las vinazas y responsable de su color oscuro.

  12. MICROALGAS E SEU POTENCIAL DE USO

    OpenAIRE

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

    2014-01-01

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

  13. Marine microalgae attack and feed on metazoans

    DEFF Research Database (Denmark)

    Berge, Terje; Poulsen, Louise K.; Moldrup, Morten

    2012-01-01

    Free-living microalgae from the dinoflagellate genus Karlodinium are known to formmassive blooms in eutrophic coastal waters worldwide and are often associated with fish kills. Natural bloom populations, recently shown to consist of the two mixotrophic and toxic species Karlodinium armiger...... of the microalgae from prey to predator of copepods couples population growth to reduced grazing pressure, promoting the persistence of blooms at high densities. K. armiger also fed on three other metazoan organisms offered, suggesting that active predation by mixotrophic dinoflagellates may be directly involved...

  14. TASAS DE CONCEPCIÓN, FERTILIDAD Y PROLIFICIDAD EN OVEJAS DE PELO ALIMENTADAS CON DIETAS ENRIQUECIDAS CON ÁCIDOS GRASOS POLIINSATURADOS

    OpenAIRE

    G Cansino-Arroyo; J Herrera-Camacho; JR Aké-López

    2009-01-01

    Las tasas de concepción, de fertilidad y prolificidad fueron evaluadas en ovejas de pelo distribuidas al azar en: un grupo testigo que recibió 800 g MS de un concentrado comercial, un grupo melaza (n = 51) alimentado con 717.6 g MS del concentrado comercial + 80.25 g MS de melaza y un grupo aceite (n = 85) mantenido con 726.8 del concentrado comercial + 30.0 g de aceite de maíz como fuente de ácidos grasos poliinsaturados. Las tasas de concepción y fertilidad fueron similares entre los tratam...

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

    Directory of Open Access Journals (Sweden)

    Bashan Yoav

    2003-12-01

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

  16. Fatty Acid Content of Indonesian Aquatic Microalgae

    Directory of Open Access Journals (Sweden)

    TRI PRARTONO

    2010-12-01

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

  17. Investigation of microalgae with photon density waves

    Science.gov (United States)

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

    2007-09-01

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

  18. Harvesting of microalgae by bio-flocculation

    NARCIS (Netherlands)

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

    2011-01-01

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

  19. Antenna size reduction in microalgae mass culture

    NARCIS (Netherlands)

    Mooij, de T.

    2016-01-01

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

  20. Towards high productivities of microalgae in photobioreactors

    NARCIS (Netherlands)

    Bosma, R.

    2010-01-01

    The biodiversity of microalgae is enormous and they represent an almost untapped source of unique algae products. Presently, there is a niche market for high-value algal products (e.g. carotenoids and fatty acids). To make commercial production of low-value bulk products possible, still many bottlen

  1. Hormone profiles in microalgae: gibberellins and brassinosteroids.

    Science.gov (United States)

    Stirk, W A; Bálint, P; Tarkowská, D; Novák, O; Strnad, M; Ördög, V; van Staden, J

    2013-09-01

    Endogenous gibberellins and brassinosteroids were quantified in 24 axenic microalgae strains from the Chlorophyceae, Trebouxiophyceae, Ulvophyceae and Charophyceae microalgae strains after 4 days in culture. This is the first report of endogenous gibberellins being successfully detected in microalgae. Between 18 and 20 gibberellins were quantified in all strains with concentrations ranging from 342.7 pg mg(-1) DW in Raphidocelis subcapitata MACC 317-4746.1 pg mg(-)(1) DW in Scotiellopsis terrestris MACC 44. Slower growing strains (S. terrestris MACC 44, Gyoerffyana humicola MACC 334, Nautococcus mamillatus MACC 716 and Chlorococcum ellipsoideum MACC 712) exhibited the highest gibberellin contents while lowest levels of gibberellins were found in faster growing strains (R. subcapitata MACC 317 and Coelastrum excentrica MACC 504). In all strains, the active gibberellin detected in the highest concentration was GA6, the predominant intermediates were GA15 and GA53 and the main biosynthetic end products were GA13 and GA51. Gibberellin profiles were similar in all strains except for the presence/absence of GA12 and GA12ald. To date this is the second report of endogenous brassinosteroids in microalgae. Brassinosteroids were detected in all 24 strains with concentrations ranging from 117.3 pg mg(-)(1) DW in R. subcapitata MACC 317-977.8 pg mg(-)(1) DW in Klebsormidium flaccidum MACC 692. Two brassinosteroids, brassinolide and castasterone were determined in all the strains. Generally, brassinolide occurred in higher concentrations than castasterone.

  2. Negative effects of Phaeocystis globosa on microalgae

    NARCIS (Netherlands)

    Liu Jiesheng, [No Value; Van Rijssel, Marion; Yang Weidong, [No Value; Peng Xichun, [No Value; Lue Songhui, [No Value; Wang Yan, [No Value; Chen Jufang, [No Value; Wang Zhaohui, [No Value; Qi Yuzao, [No Value

    2010-01-01

    The potential allelopathic effects of the microalga, Phaeocystis globosa Scherffel, on three harmful bloom algae, Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Chattonella ovata Hara et Chihara were studied. The growth of C. marina and C. ovata was markedly reduc

  3. Culture of microalgae biomass for valorization of table olive processing water

    Directory of Open Access Journals (Sweden)

    Contreras, C. G.

    2016-09-01

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

  4. Microalgae harvesting and processing: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Shelef, G.; Sukenik, A.; Green, M.

    1984-08-01

    The objective of this report is to present a discussion of the literature review performed on methods of harvesting microalgae. There is no single best method of harvesting microalgae. The choice of preferable harvesting technology depends on algae species, growth medium, algae production, end product, and production cost benefit. Algae size is an important factor since low-cost filtration procedures are presently applicable only for harvesting fairly large microalgae. Small microalgae should be flocculated into larger bodies that can be harvested by one of the methods mentioned above. However, the cells' mobility affects the flocculation process, and addition of nonresidual oxidants to stop the mobility should be considered to aid flocculation. The decision between sedimentation or flotation methods depends on the density difference between the algae cell and the growth medium. For oil-laden algae with low cell density, flotation technologies should be considered. Moreover, oxygen release from algae cells and oxygen supersaturation conditions in growth medium support the use of flotation methods. If high-quality algae are to be produced for human consumption, continuous harvesting by solid ejecting or nozzle-type disc centrifuges is recommended. These centrifuges can easily be cleaned and sterilized. They are suitable for all types of microalgae, but their high operating costs should be compared with the benefits from their use. Another basic criterion for selecting the suitable harvesting procedure is the final algae paste concentration required for the next process. Solids requirements up to 30% can be attained by established dewatering processes. For more concentrated solids, drying methods are required. The various systems for algae drying differ both in the extent of capital investment and the energy requirements. Selection of the drying method depends on the scale of operation and the use for which the dried product is intended.

  5. Microalgae as a safe food source for animals: nutritional characteristics of the acidophilic microalga Coccomyxa onubensis

    Directory of Open Access Journals (Sweden)

    Francisco Navarro

    2016-10-01

    Full Text Available Background: Edible microalgae are marine or fresh water mesophilic species. Although the harvesting of microalgae offers an abundance of opportunities to the food and pharmaceutical industries, the possibility to use extremophilic microalgae as a food source for animals is not well-documented. Objective: We studied the effects of dietary supplementation of a powdered form of the acidophilic microalga Coccomyxa onubensis on growth and health parameters of laboratory rats. Method: Four randomly organized groups of rats (n=6 were fed a standard diet (Diet 1, control or with a diet in which 0.4% (Diet 2, 1.25% (Diet 3, or 6.25% (Diet 4 (w/w of the standard diet weight was substituted with dried microalgae powder, respectively. The four groups of animals were provided ad libitum access to feed for 45 days. Results: C. onubensis biomass is rich in protein (44.60% of dry weight and dietary fiber (15.73%, and has a moderate carbohydrate content (24.8% and a low lipid content (5.4% in which polyunsaturated fatty acids represent 65% of the total fatty acid. Nucleic acids are present at 4.8%. No significant difference was found in growth rates or feed efficiency ratios of the four groups of rats. Histological studies of liver and kidney tissue revealed healthy organs in control and C. onubensis-fed animals, while plasma hematological and biochemical parameters were within healthy ranges for all animals. Furthermore, animals fed a microalgae-enriched diet exhibited a statistically significant decrease in both blood cholesterol and triglyceride levels. The blood triglyceride content and very low density lipoprotein-cholesterol levels decreased by about 50% in rats fed Diet 4. Conclusions: These data suggest that C. onubensis may be useful as a food supplement for laboratory animals and may also serve as a nutraceutical in functional foods. In addition, microalgae powder-supplemented diets exerted a significant hypocholesterolemic and hypotriglyceridemic

  6. Catalytic deoxygenation of microalgae oil to green hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chen; Bruck, Thomas; Lercher, Johannes A.

    2013-05-14

    Microalgae are high potential raw biomass material for triglyceride feedstock, due to their high oil content and rapid growth rate, and because algae cultivation does not compete with edible food on arable land. This review addresses first the microalgae cultivation with an overview of the productivity and growth of microalgae, the recovery of lipids from the microalgae, and chemical compositions of microalgae biomass and microalgal oil. Second, three basic approaches are discussed to downstream processing for the production of green gasoline and diesel hydrocarbons from microalgae oil, including cracking with zeolite, hydrotreating with supported sulfided catalysts and hydrodeoxygenation with non-sulfide metal catalysts. For the triglyceride derived bio-fuels, only “drop-in” gasoline and diesel range components are discussed in this review.

  7. Biotechnological production of value-added carotenoids from microalgae

    Science.gov (United States)

    Wichuk, Kristine; Brynjólfsson, Sigurður; Fu, Weiqi

    2014-01-01

    We recently evaluated the relationship between abiotic environmental stresses and lutein biosynthesis in the green microalga Dunaliella salina and suggested a rational design of stress-driven adaptive evolution experiments for carotenoids production in microalgae. Here, we summarize our recent findings regarding the biotechnological production of carotenoids from microalgae and outline emerging technology in this field. Carotenoid metabolic pathways are characterized in several representative algal species as they pave the way for biotechnology development. The adaptive evolution strategy is highlighted in connection with enhanced growth rate and carotenoid metabolism. In addition, available genetic modification tools are described, with emphasis on model species. A brief discussion on the role of lights as limiting factors in carotenoid production in microalgae is also included. Overall, our analysis suggests that light-driven metabolism and the photosynthetic efficiency of microalgae in photobioreactors are the main bottlenecks in enhancing biotechnological potential of carotenoid production from microalgae. PMID:24691165

  8. Cultivo de microalgas com vinhaça digerida anaerobiamente

    OpenAIRE

    Serejo, Mayara Leite

    2012-01-01

    A busca por energias alternativas como os bicombustíveis cresce a cada ano e tem atraído atenção de muitas grupos de pesquisa, ganhando destaque a produção de microalgas para obtenção de biodiesel ou biogás. A utilização de resíduos para o cultivo de microalgas pode ser uma alternativa vantajosa, visto que alguns efluentes contêm quantidades de nutrientes necessários ao crescimento das microalgas. Nesta pesquisa foram estudadas as condições ideais de cultivo de microalgas utilizando a vinhaça...

  9. Lipid extraction from microalgae using a single ionic liquid

    Science.gov (United States)

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

    2013-05-28

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

  10. Learning sustainability by developing a solar dryer for microalgae retrieval

    Directory of Open Access Journals (Sweden)

    Benedita Malheiro

    2016-01-01

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

  11. Used water resource recovery using green microalgae

    DEFF Research Database (Denmark)

    Wágner, Dorottya Sarolta

    A paradigm shift is promoted in wastewater treatment whereby wastewater is considered as a source of nutrients, water and energy, rather than waste and it is referred to as used water. Microalgae cultivation on used water resources offers the potential to recover nitrogen, phosphorus, water...... and energy. When coupling with used water treatment, microalgae is mostly considered to produce energy through biofuel production. A novel used water resource recovery approach was presented earlier, referred to as TRENS – a fully biochemical process for the removal, recovery and reuse of used water...... content can be used for aquifer recharge. Design and optimization of bacterial-microalgal systems requires process models that can be readily combined with consensus used water treatment models, e.g. the activated sludge models (ASM). Previous microalgal process models cannot be used for such purposes...

  12. Negative effects of Phaeocystis globosa on microalgae

    Science.gov (United States)

    Liu, Jiesheng; van Rijssel, Marion; Yang, Weidong; Peng, Xichun; Lü, Songhui; Wang, Yan; Chen, Jufang; Wang, Zhaohui; Qi, Yuzao

    2010-07-01

    The potential allelopathic effects of the microalga, Phaeocystis globosa Scherffel, on three harmful bloom algae, Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Chattonella ovata Hara et Chihara were studied. The growth of C. marina and C. ovata was markedly reduced when the organisms were co-cultured with P. globosa or cultured in cell-free spent medium. Haemolytic extracts from P. globosa cells in the senescence phase had a similar inhibitory effect on the three harmful bloom algae. However, P. globosa had less influence on the brine shrimp, Artemia salina. These results indicate that P. globosa may have an allelopathic effect on microalgae, which would explain the superior competitive abilities of P. globosa. Because the addition of the haemolytic toxins from P. globosa had similar effects on algae as spent media, these compounds may be involved in the allelopathic action of P. globosa.

  13. Antioxidant activity of the microalga Spirulina maxima

    OpenAIRE

    Miranda, M. S.; Cintra,R.G.; S.B.M. Barros; J. Mancini-Filho

    1998-01-01

    Spirulina maxima, which is used as a food additive, is a microalga rich in protein and other essential nutrients. Spirulina contains phenolic acids, tocopherols and ß-carotene which are known to exhibit antioxidant properties. The aim of the present study was to evaluate the antioxidant capacity of a Spirulina extract. The antioxidant activity of a methanolic extract of Spirulina was determined in vitro and in vivo. The in vitro antioxidant capacity was tested on a brain homogenate incubated ...

  14. Crescimento e metabolismo do nitrogênio em juvenis de Trachinotus marginatus alimentados com diferentes níveis proteicos

    Directory of Open Access Journals (Sweden)

    E.M. Silva

    2015-02-01

    Full Text Available O objetivo deste trabalho foi avaliar o crescimento e alterações no metabolismo do nitrogênio, além da composição do fígado e do músculo de juvenis de pampo Trachinotus marginatus alimentados com 43, 54 ou 64% de proteína bruta (PB43, PB54 e PB64, respectivamente. Grupos de 10 juvenis (1,47±0,14g foram estocados em nove tanques de 50L, em sistema de recirculação de água marinha, durante 55 dias, alimentados quatro vezes ao dia com as rações pré-definidas. O ganho em peso, a taxa de crescimento específico e a conversão alimentar não apresentaram diferença significativa (P>0,05. Contudo, o acréscimo de proteína consumida aumentou o índice hepatossomático e a taxa de excreção de amônia pós-prandial, bem como diminuiu a retenção proteica. Os peixes alimentados com a dieta PB43 apresentaram menor concentração da transaminase glutâmico oxalacética hepática, além de menor concentração de triglicerídeos no músculo e fígado (P0,05, excetuando o maior teor de lipídios da carcaça no tratamento PB43. Concluímos que a melhor utilização da proteína por juvenis de pampo é observada quando eles são alimentados com uma dieta contendo 43% de proteína.

  15. Microalgae: An Alternative Source of Renewable Energy

    Directory of Open Access Journals (Sweden)

    A. Z. A. Saifullah

    2016-08-01

    Full Text Available This paper presents an overview on the potentiality of microalgae with particular emphasis as a sustainable renewable energy source for biodiesel. One of the most important dilemmas of the modern world is to supply maximal amount of energy with minimal environmental impact. The total energy demand of our planet is increasing with population growth whereas the fossil fuel reserves are dwindling swiftly. Biodiesel produced from biomass is widely considered to be one of the most sustainable alternatives to fossil fuels and a viable means for energy security and environmental and economic sustainability. But as a large area of arable land is required to cultivate biodiesel producing terrestrial plants, it may lead towards food scarcity and deforestation. Microalgae have a number of characteristics that allow the production concepts of biodiesel which are significantly more sustainable than their alternatives. Microalgae possess high biomass productivity, oils with high lipid content, fast growth rates, possibility of utilizing marginal and infertile land, capable of growing in salt water and waste streams, and capable of utilizing solar light and CO2 gas as nutrients.

  16. Applications of Imaging Flow Cytometry for Microalgae.

    Science.gov (United States)

    Hildebrand, Mark; Davis, Aubrey; Abbriano, Raffaela; Pugsley, Haley R; Traller, Jesse C; Smith, Sarah R; Shrestha, Roshan P; Cook, Orna; Sánchez-Alvarez, Eva L; Manandhar-Shrestha, Kalpana; Alderete, Benjamin

    2016-01-01

    The ability to image large numbers of cells at high resolution enhances flow cytometric analysis of cells and cell populations. In particular, the ability to image intracellular features adds a unique aspect to analyses, and can enable correlation between molecular phenomena resulting in alterations in cellular phenotype. Unicellular microalgae are amenable to high-throughput analysis to capture the diversity of cell types in natural samples, or diverse cellular responses in clonal populations, especially using imaging cytometry. Using examples from our laboratory, we review applications of imaging cytometry, specifically using an Amnis(®) ImageStream(®)X instrument, to characterize photosynthetic microalgae. Some of these examples highlight advantages of imaging flow cytometry for certain research objectives, but we also include examples that would not necessarily require imaging and could be performed on a conventional cytometer to demonstrate other concepts in cytometric evaluation of microalgae. We demonstrate the value of these approaches for (1) analysis of populations, (2) documentation of cellular features, and (3) analysis of gene expression.

  17. Laboratory apparatus to evaluate microalgae production

    Directory of Open Access Journals (Sweden)

    L. R. S. Gris

    2013-09-01

    Full Text Available The application of microalgae for energy purposes and CO2 biomitigation continues to present a number of challenges, including the optimization of culture conditions. The application of experimental designs for microalgae cultivation is difficult, since experiments involving such microorganisms generally last days or weeks. This work proposes a multipurpose laboratory apparatus for the optimization of microalgae experimental conditions that simultaneously enables the evaluation of variables such as temperature, irradiance, photoperiod and CO2 concentration in the aeration stream, as well as variables related to the concentration of culture media nutrients. A case study is also presented in which temperature, concentration of f/2 medium sodium nitrate and the effects of incident light intensity on Nannochloropsis oculata lipid content are evaluated. Experiments were carried out following central composite designs, in batch cultivation within an airlift photobioreactor apparatus. The best experimental result was obtained at 21 ºC, 119 mg/L NaNO3 and 137 µE.m-2.s-1, corresponding to 41.8% lipids and 211.9 mg.L-1 final lipid concentrations.

  18. Evaluation of Microalgae as Microbial Fertilizer

    Directory of Open Access Journals (Sweden)

    Onder Uysal

    2015-06-01

    Full Text Available Microalgal biomass is utilized in many fields such as food, agriculture, energy, and cosmetic sectors. It is very well known that chemical fertilizer adversely affect soil, plant, and environment. To reduce this effect in recent years, interest to organic farming has been increasing. In this study, microbial fertilizers obtained from microalgae was applied to maize and wheat plants. Microbial fertilizers at four different doses were applied, namely, S1 (control: 0,00 dose-non fertilizer, S2 (0.50 dose, S3 (1.00 dose, and S4 (1.50 dose. All measurements were made at the end of 30th days.  The best results were determined for S3 dose applications. During the experiment, the soil temperature between 15 and 30⁰C and soil pH values between 6.5 and 8.5 were maintained. The results showed that the amount of soil organic matter and the water holding capacity were improved. Finally, microbial fertilizers obtained from microalgae can be reported to have positive effects on soil, plants and therefore environment. Keywords: Microalgae, biomass, agriculture, fertilizer, microbial

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  20. Magnetic microparticles for harvesting Dunaliella tertiolecta microalgae

    Science.gov (United States)

    Manousakis, Emmanouil; Manariotis, Ioannis D.

    2016-04-01

    Microalgae based biofuels have been considered as a sustainable alternative to traditional fuels due to the higher biomass yield and lipid productivity, and the ability to be cultivated in non arable land making them not antagonistic with food supply chain. Due to the dilute nature of algal cultures and the small size of algae cells, the cost of microalgae harvesting is so far a bottleneck in microalgal based biofuel production. It is estimated that the algal recovery cost is at least 20-30% of the total biomass production cost. Various processes have been employed for the recovery of microalgal biomass, which include centrifugation, gravity separation, filtration, flocculation, and flotation. Recently, magnetophoric harvesting has received increased attention for algal separation, although it has been first applied for algal removal since the mid of 1970s. The magnetic separation process is based on bringing in contact the algal cells with the magnetic particles, and separating them from the liquid by an external magnetic force. The aim of this work was to investigate the harvesting of microalgae cells using Fe3O4 magnetic microparticles (MPs). Dunaliella tertiolecta was selected as a representative for marine microalgae. D. tertiolecta was cultivated under continuous artificial light, in 20 L flasks. Fe3O4 MPs were prepared by microwave irradiation of FeSO4 7H2O in an alkaline solution. Numerous batch and flow-through experiments were conducted in order to investigate the effect of the magnetic material addition on microalgae removal. Batch experiments were conducted examining different initial algal and MPs concentration, and algal culture volume. Flow-through experiments were conducted in a laboratory scale column made of Plexiglass. External magnetic field was applied by arranging at various points across the column length NdFeB magnets. Algal removal in flow-through experiments ranged from 70 to 85% depending on the initial MPs concentration and the hydraulic

  1. Enzyme assisted protein extraction from rapeseed, soybean, and microalgae meals

    NARCIS (Netherlands)

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

    2013-01-01

    Oilseed meals that are by-products from oil production are potential resources for protein. The aim of this work is to investigate the use of enzymes in assisting in the extraction of protein from different oilseed meals, namely rapeseed, soybean, and microalgae meals. In addition, microalgae withou

  2. Chemical Profiles of Microalgae with Emphasis on Lipids: Final Report

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-02-01

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

  3. Techno-economical evaluation of protein extraction for microalgae biorefinery

    NARCIS (Netherlands)

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

    2016-01-01

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

  4. Caracterización y perfil lipídico de aceites de microalgas

    Directory of Open Access Journals (Sweden)

    Lesly Tejeda-Benítez

    2015-05-01

    Full Text Available El uso creciente del biodiésel ha impulsado la búsqueda de nuevas materias primas, dentro de las que se destacan las microalgas. En esta investigación se estudió el cultivo de las microalgas Chlorella sp. y Dunaliella salina bajo diferentes condiciones de pH y concentración de nitrógeno (mgL-1, y la caracterización de los aceites obtenidos, con el fin de evaluar su potencial uso como materia prima en la producción de biodiésel. La D. salina alcanzó una máxima concentración celular de 1.15x106 células mL-1 en 6 días de cultivo en unas condiciones de 8.5 pH y 0.1 mg L-1 concentración de nitrógeno, mientras que Chlorella sp. presentó una máxima concentración celular de 2.6x107 células mL-1 en 14 días de cultivo en unas condiciones de 7.5 pH y 0.1 mg L-1 concentración de nitrógeno. La extracción de aceite intracelular de las microalgas cultivadas bajo las mejores condiciones de crecimiento celular se realizó empleando el método modificado de Bligh & Dyer. Al determinar el perfil de ácidos grasos de los aceites extraídos de ambas microalgas, se  encontraron en mayor proporción dos ácidos grasos insaturados: ácido linolénico y ácido oleico. En el aceite de D. salina se encontró una concentración de 51% p/p de ácido linolénico, mientras que para el aceite de Chlorella sp. fue de 39% p/p. Con relación al ácido oleico, el aceite de Chrorella sp. presentó una concentración de 35% p/p, superior al aceite de D. salina, con 25% p/p.

  5. INMOVILIZACIÓN DE LAS MICROALGAS Scenedesmus ovalternus (Scenedesmaceae Y Chlorella vulgaris (Chlorellaceae EN ESFERAS DE ALGINATO DE CALCIO

    Directory of Open Access Journals (Sweden)

    Mario Andres Forero-Cujiño

    2016-04-01

    Full Text Available En este trabajo se describe la técnica de inmovilización de microalgas en esferas de alginato de calcio. Se emplearon las especies Scenedesmus ovalternus y Chlorella vulgaris, se determinó la estabilidad de las esferas, la cinética de crecimiento y la concentración de las microalgas en el interior de las esferas. Chlorella vulgaris alcanzó mayores densidades poblacionales y tasas de crecimiento más altas cuando se inmovilizó en concentraciones del 10 % v/v con el alginato (1,31*106 cél/ml. Para Scenedesmus ovalternus se observó una mayor densidad poblacional y una mayor tasa de crecimiento cuando se inmovilizó en concentraciones del 20 % v/v (7,06*105 cél/ml. Estos resultados son útiles para aplicaciones prácticas de las algas encapsuladas, tales como el biomonitoreo o la biorremediación.Immobilization of Microalgae Scenedesmus ovalternus (Scenedesmaceae and Chlorella vulgaris (Chlorellaceae in Calcium Alginate BeadsThis paper describes the immobilization technique of microalgae in calcium alginate beads. Scenedesmus ovalternus and Chlorella vulgaris species were used. The stability of beads, the kinetics of growth and the concentrations of microalgae inside the beads were determined. The higher density and the upper growth rate of Chlorella vulgaris occurred when it was immobilized in alginate at a concentration of 10 %v/v (1,31*106 cél/ml. Scenedesmus ovalternus achieved a higher population density and an elevated growth rate when it was immobilized at a concentration of 20 % v/v (7,06*105 cél/ml. These results are useful for subsequent applications of the encapsulated algae, such as biomonitoring and bioremediation.

  6. Microalgae cultivation in sugarcane vinasse: Selection, growth and biochemical characterization.

    Science.gov (United States)

    Santana, Hugo; Cereijo, Carolina R; Teles, Valérya C; Nascimento, Rodrigo C; Fernandes, Maiara S; Brunale, Patrícia; Campanha, Raquel C; Soares, Itânia P; Silva, Flávia C P; Sabaini, Priscila S; Siqueira, Félix G; Brasil, Bruno S A F

    2017-03-01

    Sugarcane ethanol is produced at large scale generating wastes that could be used for microalgae biomass production in a biorefinery strategy. In this study, forty microalgae strains were screened for growth in sugarcane vinasse at different concentrations. Two microalgae strains, Micractinium sp. Embrapa|LBA32 and C. biconvexa Embrapa|LBA40, presented vigorous growth in a light-dependent manner even in undiluted vinasse under non-axenic conditions. Microalgae strains presented higher biomass productivity in vinasse-based media compared to standard Bold's Basal Medium in cultures performed using 15L airlift flat plate photobioreactors. Chemical composition analyses showed that proteins and carbohydrates comprise the major fractions of algal biomass. Glucose was the main monosaccharide detected, ranging from 46% to 76% of the total carbohydrates content according to the strain and culture media used. This research highlights the potential of using residues derived from ethanol plants to cultivate microalgae for the production of energy and bioproducts.

  7. Cationic polymers for successful flocculation of marine microalgae.

    Science.gov (United States)

    't Lam, G P; Vermuë, M H; Olivieri, G; van den Broek, L A M; Barbosa, M J; Eppink, M H M; Wijffels, R H; Kleinegris, D M M

    2014-10-01

    Flocculation of microalgae is a promising technique to reduce the costs and energy required for harvesting microalgae. Harvesting marine microalgae requires suitable flocculants to induce the flocculation under marine conditions. This study demonstrates that cationic polymeric flocculants can be used to harvest marine microalgae. Different organic flocculants were tested to flocculate Phaeodactylum tricornutum and Neochloris oleoabundans grown under marine conditions. Addition of 10 ppm of the commercial available flocculants Zetag 7557 and Synthofloc 5080H to P. tricornutum showed a recovery of, respectively, 98% ± 2.0 and 94% ± 2.9 after flocculation followed by 2h sedimentation. Using the same flocculants and dosage for harvesting N. oleoabundans resulted in a recovery of 52% ± 1.5 and 36% ± 11.3. This study shows that cationic polymeric flocculants are a viable option to pre-concentrate marine cultivated microalgae via flocculation prior to further dewatering.

  8. Colloid's influences on microalgae growth as a potential environmental factor

    Institute of Scientific and Technical Information of China (English)

    赵新淮; 张正斌; 刘莲生

    2003-01-01

    The role of colloid as "colloid pump" in the ocean is well known. The important influence of colloid in seawater on the growth of microalga was found in our 1999-2000 study. Colloid concentrates were obtained by employing a cross-flow filtration systen to ultrafilter seawater (which had been pre-filtrated by 0.45 μm acetate cellulose membrane) successively with different membranes. Ultrafiltration retentions (we called them colloid concentrates ) together with control sample ( seawater without colloid) were then inoculated with two species of microalgae and cultivated in selected conditions. Monitoring of microalgae growth during cultivation showed that all colloid concentrates had obvious influence on the growth of the microalgae studied. Addition of Fe(OH)3 colloid or organic colloid (protein or carbohydrate) to the control sample enhanced the microalgae's growth.

  9. Novel approaches of producing bioenergies from microalgae: A recent review.

    Science.gov (United States)

    Tan, Chung Hong; Show, Pau Loke; Chang, Jo-Shu; Ling, Tau Chuan; Lan, John Chi-Wei

    2015-11-01

    Microalgae have caught the world's attention for its potential to solve one of the world's most pressing issues-sustainable green energy. Compared to biofuels supplied by oil palm, rapeseed, soybean and sugar cane, microalgae alone can be manipulated to generate larger amounts of biodiesel, bioethanol, biohydrogen and biomass in a shorter time. Apart from higher productivity, microalgae can also grow using brackish water on non-arable land, greatly reducing the competition with food and cash crops. Hence, numerous efforts have been put into the commercialisation of microalgae-derived biofuel by both the government and private bodies. This paper serves to review conventional and novel methods for microalgae culture and biomass harvest, as well as recent developments in techniques for microalgal biofuel production.

  10. New insights into shear-sensitivity in dinoflagellate microalgae.

    Science.gov (United States)

    Gallardo-Rodríguez, J J; López-Rosales, L; Sánchez-Mirón, A; García-Camacho, F; Molina-Grima, E; Chalmers, J J

    2016-01-01

    A modification of a flow contraction device was used to subject shear-sensitive microalgae to well-defined hydrodynamic forces. The aim of the study was to elucidate if the inhibition of shear-induced growth commonly observed in dinoflagellate microalgae is in effect due to cell fragility that results in cell breakage even at low levels of turbulence. The microalgae assayed did not show any cell breakage even at energy dissipation rates (EDR) around 10(12)Wm(-3), implausible in culture devices. Conversely, animal cells, tested for comparison purposes, showed high physical cell damage at average EDR levels of 10(7)Wm(-3). Besides, very short exposures to high levels of EDR promoted variations in the membrane fluidity of the microalgae assayed, which might trigger mechanosensory cellular mechanisms. Average EDR values of only about 4·10(5)Wm(-3) increased cell membrane fluidity in microalgae whereas, in animal cells, they did not.

  11. Using wet microalgae for direct biodiesel production via microwave irradiation.

    Science.gov (United States)

    Cheng, Jun; Yu, Tao; Li, Tao; Zhou, Junhu; Cen, Kefa

    2013-03-01

    To address the large energy consumption of microalgae dewatering and to simplify the conventional two-step method (cellular lipid extraction and lipid transesterification) for biodiesel production, a novel process for the direct conversion of wet microalgae biomass into biodiesel by microwave irradiation is proposed. The influences of conventional thermal heating and microwave irradiation on biodiesel production from wet microalgae biomass were investigated. The effects of using the one-step (simultaneous lipid extraction and transesterification) and two-step methods were also studied. Approximately 77.5% of the wet microalgal cell walls were disrupted under microwave irradiation. The biodiesel production rate and yield from wet microalgae biomass obtained through the one-step process using microwave irradiation were 6-fold and 1.3-fold higher than those from wet microalgae obtained through the two-step process using conventional heating.

  12. PRODUCCIÓN DE BIODIESEL A PARTIR DE MICROALGAS: PARÁMETROS DEL CULTIVO QUE AFECTAN LA PRODUCCIÓN DE LÍPIDOS Biodiesel Production from Microalgae: Cultivation Parameters that Affect Lipid Production

    Directory of Open Access Journals (Sweden)

    MARTHA TRINIDAD ARIAS PEÑARANDA

    2013-04-01

    Full Text Available Las microalgas poseen la capacidad para mitigar las emisiones de CO2 y producir lípidos, por lo que se consideran con potencial para la obtención de biocombustibles de tercera generación. La presente revisión proporciona información actualizada de la influencia de las condiciones de cultivo, sobre la obtención de lípidos con una productividad elevada y perfil adecuado para la producción de biodiesel, se proporciona una síntesis de resultados de investigaciones realizadas en los últimos 13 años en diversas partes del mundo. En la literatura consultada, los autores concluyen que aunque el comportamiento de las microalgas ante condiciones de estrés fisiológico es variable entre especies; la limitación de nutrientes especialmente nitrógeno y fósforo, asociado al crecimiento heterotrófico o a altas intensidades luminosas en fototrofía se consideran como las estrategias más eficientes para incrementar el contenido de lípidos en las microalgas, en particular de triglicéridos constituidos por ácidos grasos saturados y monoinsaturados, ideales para la producción de biodiesel. De igual forma, señalan que la presencia de pequeñas cantidades de CO2 y la cosecha de la biomasa en la fase estacionaria de crecimiento, incrementan el contenido de lípidos y disminuyen el número de insaturaciones de los ácidos grasos que lo conforman.The microalgae have the capacity to mitigate CO2 emissions and to produce lipids, which are considered with potential to obtain third-generation biofuel. This review provides updated information of the influence of culture conditions on the lipids production with high productivity and profile suitable for the biodiesel production. This document presents a compilation of research conclusions over the last 13 years around the world. In the literature consulted, the authors conclude that although the behavior of microalgae at physiological stress conditions, varies between species; the nutrients limitation

  13. Estudo comparativo do ciclo evolutivo de Rhodnius neglectus alimentados em pombos ou camundongos

    Directory of Open Access Journals (Sweden)

    Liléia Diotaiuti

    1987-06-01

    Full Text Available Baseados no encontro de 77,2% de reação de precipitina positiva para soro antiave de R. neglectus capturados em palmeiras da periferia de Belo Horizonte, estudamos o ciclo evolutivo de uma colonia recém-estabelecida no laboratório alimentada com sangue de pombo ou camundongo, na expectativa de demonstrarmos maior adaptação deste triatomíneo ao sangue da ave. Para comparação, estudamos o ciclo evolutivo destes insetos numa colônia há muito mantida em insetário. Nossos resultados mostram um desenvolvimento mais rápido da colônia recém- estabelecida, assim como do lote de triatomíneos alimentado em camundongo. Esses achados sugerem menor potencial biológico para triatomíneos criados por longo tempo em insetário em comparação a novas colônias. Sendo as aves os principais habitantes das palmeiras, a aparente preferência alimentar por sangue de aves demonstrada pela reação de precipitina parece ser circunstancial e não seletiva na busca do sangue com o qual o triatomíneo obteria melhor desenvolvimento.

  14. Nutrición en juveniles del langostino Macrobrachium carcinus (Cmstacea: Decapoda) con dietas de residuos vegetales y marinos

    OpenAIRE

    Casas-Sánchez, Ruth; Vaillard-Nava, Yvette; Re-Araujo, Ana Denisse

    2015-01-01

    Juveniles del langostino Macrobrachium carcinus fueron alimentados con dos dietas: de desechos de restaurante (dieta 1) y de pescado y productos vegetales (dieta ll). Las dietas fueron evaluadas mediante análisis proximal, bioensayos de digestibilidad (Eficiencia de Asimilación), bioensayos de crecimiento y Factor de Conversión (FCR). A pesa:[" de que, los organismos asimilaron con mayor eficiencia la dieta 1, el crecimiento no fue diferente, siendo éste, en promedio para los tres meses del e...

  15. Photo-biotechnological hydrogen production with microalgae

    Energy Technology Data Exchange (ETDEWEB)

    Lehr, F.; Posten, C. [Inst. fuer Bio- und Lebensmitteltechnik, Univ. Karlsruhe (Germany); Renz, A.; Schaub, G. [Engler-Bunte-Inst., Univ. Karlsruhe (Germany)

    2008-07-01

    Some types of unicellular green algae have evolved the ability to use solar energy to produce hydrogen by splitting water. Compared to photosynthesis with terrestrial plants, microalgal hydrogen production exhibits higher photo conversion efficiencies, very low water demands, and no competition with agriculture for arable land use. The overall process includes microalgae growth by photosynthesis and subsequent hydrogen production. The main challenge in process development is the design of photo bioreactors with minimum energy demand for mixing and liquid handling and maximum overall efficiency. In an ongoing research project, process engineering fundamentals are presently being investigated in order to allow more accurate process design and cost estimates. (orig.)

  16. Allelopathy as a potential strategy to improve microalgae cultivation.

    Science.gov (United States)

    Bacellar Mendes, Leonardo Brantes; Vermelho, Alane Beatriz

    2013-10-21

    One of the main obstacles for continuous productivity in microalgae cultivation is the presence of biological contaminants capable of eliminating large numbers of cells in a matter of days or even hours. However, a number of strategies are being used to combat and prevent contamination in microalgae cultivation. These strategies include the use of extreme conditions in the culture media such as high salinity and high pH to create an unfavorable environment for the competitive organisms or predators of the microalgae. Numerous studies have explored the potential of naturally occurring bioactive secondary metabolites, which are natural products from plants and microorganisms, as a source of such compounds. Some of these compounds are herbicides, and marine and freshwater microalgae are a source of these compounds. Microalgae produce a remarkable diversity of biologically active metabolites. Results based on the allelopathic potential of algae have only been described for laboratory-scale production and not for algae cultivation on a pilot scale. The adoption of allelopathy on microalgal strains is an unexplored field and may be a novel solution to improve algae production. Here we present information showing the diversity of allelochemicals from microalgae and the use of an allelopathic approach to control microalgae cultivation on a pilot scale based on R&D activities being carried out in Brazil for biodiesel production.

  17. Lipid profiling of some authotrophic microalgae grown on waste water

    DEFF Research Database (Denmark)

    Safafar, Hamed; Jacobsen, Charlotte; Møller, Per

    the most suitable microalgae and downstream processing for food and feed production. The present study is part of a big project funded by GUDP (green development and demonstration program of ministry of agriculture and fisheries of Denmark) which aims at developing new processing technologies, so...... that microalgae-biomass can be used as an alternative valuable resource in fish feed. In this work, 10 fresh water and marine microalgae from Chlorella, Scenedesmus, Haematococcus, Nannochloropsis, Nannochloropsis and Dunialiella species grown in waste water in Kalundborg micro algal facility were harvested...

  18. Design and operation of an outdoor microalgae test facility

    Energy Technology Data Exchange (ETDEWEB)

    Weissman, J.C.; Tillett, D.M.; Goebel, R.P. (Microbial Products, Inc., Vacaville, CA (USA))

    1989-10-01

    The objective of the project covered in this report is to establish and operate a facility in the American Southwest to test the concept of producing microalgae on a large scale. This microalgae would then be used as a feedstock for producing liquid fuels. The site chosen for this project was an existing water research station in Roswell, New Mexico; the climate and water resources are representative of those in the Southwest. For this project, researchers tested specific designs, modes of operation, and strains of microalgae; proposed and evaluated modifications to technological concepts; and assessed the progress toward meeting cost objectives.

  19. Moisture sorption characteristics of microalgae Spirulina platensis

    Directory of Open Access Journals (Sweden)

    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.

  20. Emergent Sources of Prebiotics: Seaweeds and Microalgae

    Directory of Open Access Journals (Sweden)

    Maria Filomena de Jesus Raposo

    2016-01-01

    Full Text Available In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen.

  1. Emergent Sources of Prebiotics: Seaweeds and Microalgae

    Science.gov (United States)

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

    2016-01-01

    In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS) or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen. PMID:26828501

  2. Emergent Sources of Prebiotics: Seaweeds and Microalgae.

    Science.gov (United States)

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

    2016-01-28

    In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS) or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen.

  3. Perfil sanguíneo de novilhos Nelore alimentados com diferentes fontes da energia da dieta em confinamento

    OpenAIRE

    Maia Filho, Geraldo Helber Batista; Souza,Rafahel Carvalho; Costa,Patrícia Monteiro; Silva, Sílvio Costa e; Andrade Júnior, José Mauro de Carvalho; Barbosa, Steffany Oliveira

    2015-01-01

    Bovinos confinados estão mais susceptíveis ao desenvolvimento de desordens metabólicas o que pode resultar em decréscimo na produtivida­de. Foram avaliados os perfis sanguíneos em 32 bovinos Nelore alimentados com diferentes fontes de energia na dieta em confinamento, sendo MGI - die­ta composta por milho grão inteiro e suplemento comercial peletizado; SCMF - dieta composta por silagem de capim elefante e milho floculado como fonte energética; SCPC - dieta composta por silagem de capim elefan...

  4. Morfometria testicular de cabritos alimentados com óleo de licuri (Syagrus coronata

    Directory of Open Access Journals (Sweden)

    L.P. Barbosa

    2012-08-01

    Full Text Available Determinou-se o desenvolvimento testicular de caprinos pré-púberes alimentados com óleo de licuri (Syagrus coronata na dieta. Foram utilizados 19 cabritos ¾ Boer, recém-desmamados, com média de idade de três meses. Os animais, submetidos a um período de 75 dias de confinamento, receberam alimentação composta por: farelo de milho, farelo de soja, feno picado de tifton 85 e de óleo de licuri com base na matéria seca. Os animais foram distribuídos em quatro grupos: sem lipídio adicional (n= 5; com 1,5% de óleo de licuri (n= 5; com 3,0% de óleo de licuri (n= 5; e com 4,5% de óleo de licuri (n= 4. As avaliações de peso corporal e de biometria testicular foram realizadas quinzenalmente. Após o período de confinamento, os animais foram abatidos para determinação do peso dos testículos, peso dos epidídimos e índice gonadossomático. A adição de óleo de licuri em até 4,5% na dieta de caprinos pré-púberes não alterou o desenvolvimento testicular com base nas características da biometria e morfometria testicular, indicando que a inclusão de até 4,5% de óleo de licuri na dieta pode ser utilizada.

  5. Desenvolvimento de alevinos de trairão alimentados com dietas artificiais em tanques de cultivo

    Directory of Open Access Journals (Sweden)

    Luz Ronald Kennedy

    2001-01-01

    Full Text Available Este experimento foi realizado no Setor de Hidrobiologia e Piscicultura do Departamento de Biologia Animal da Universidade Federal de Viçosa. Alevinos de trairão (Hoplias lacerdae previamente treinados a aceitar dietas artificiais foram selecionados por tamanho e estocados em três tanques com capacidade de 5000 litros cada, numa biomassa de 36,72 g cada. Após 30 dias de experimento, os peixes foram novamente separados por tamanho e redistribuídos nos mesmos tanques, numa densidade de 5 peixes/m², por mais 30 dias. Diariamente, às 8 e 14 h, os peixes foram alimentados com ração comercial extrusada (42%PB. Ao final de cada período experimental foram determinados: taxa de sobrevivência, ganho de biomassa, comprimento padrão e conversão alimentar. Observaram-se taxas médias de sobrevivência de 99,23 e 89,33%, conversão alimentar de 1,3:1,0 e 1,05:1,0, ganho de biomassa de 92,19 e 133,08 g nos dois períodos, respectivamente. Com relação ao comprimento padrão, foi comum a ocorrência de crescimento desigual dos alevinos nos dois períodos em todos os tanques, confirmando a necessidade de classificações periódicas, por tamanho, em criações de peixes carnívoros. Estes dados demonstram que o trairão apresenta potencial zootécnico para ser cultivado com a utilização de dietas artificiais, desde que treinados a aceitar ração comercial previamente.

  6. Consumo e desempenho produtivo de ovinos alimentados com dietas que continham coprodutos do desfibramento do sisal

    Directory of Open Access Journals (Sweden)

    R.D. Santos

    2011-12-01

    Full Text Available Avaliaram-se o desempenho produtivo e o consumo de nutrientes e frações fibrosas em ovinos alimentados com dietas contendo coprodutos do desfibramento do sisal, Agave sisalana. Foram utilizados 24 ovinos, machos, alojados em baias individuais. O delineamento experimental utilizado foi o inteiramente ao acaso, com quatro tratamentos e seis repetições. Os tratamentos consistiram em quatro dietas isoproteicas, em que: i dieta padrão, contendo 38% de volumoso (silagem de milheto e 62% de concentrado (milho, farelo de soja e ureia; ii inclusão de 20% da silagem de mucilagem do sisal em substituição à silagem de milheto; iii inclusão de 20% da silagem de mucilagem associada ao pó da batedeira como aditivo em substituição à silagem de milheto; iv inclusão de 20% do feno da mucilagem em substituição à silagem de milheto. O peso corporal final, os ganhos médio diário e total e a conversão alimentar dos ovinos não foram influenciados pelas dietas avaliadas (P>0,05. Os consumos dos nutrientes, em g/dia e em %PC e g/kg0,75, não sofreram influência das dietas. Os resultados indicam que as dietas à base de coprodutos do sisal podem ser utilizadas como alternativa volumosa, além de possibilitar o aumento da rentabilidade da atividade na região semiárida brasileira.

  7. Desempenho de cordeiros alimentados com diferentes níveis protéicos

    Directory of Open Access Journals (Sweden)

    Zundt Marilice

    2002-01-01

    Full Text Available O experimento foi conduzido com o objetivo de avaliar níveis crescentes de proteína bruta (PB na dieta de cordeiros em confinamento, por meio de seus efeitos sobre o desempenho animal. Trinta e dois cordeiros "tricross" (¹/2 Texel + fraction one-quarter Bergamácia + fraction one-quarter Corriedale, sendo 16 machos inteiros e 16 fêmeas, com idade média de 5 meses e peso vivo de 30 kg , foram alimentados durante 57 dias com dietas isoenergéticas (72% NDT, variando os níveis protéicos (12, 16, 20 e 24 % PB. Os animais foram identificados, pesados e distribuídos nos quatro tratamentos. Os cordeiros permaneceram em baias individuais, cobertas, com piso ripado e suspenso. Os parâmetros estudados foram ganho de peso, consumo de matéria seca, conversão alimentar e o custo de produção do quilograma de carcaça. A utilização de dietas, com diferentes níveis protéicos na terminação de cordeiros, mostrou efeito linear positivo para ganho de peso e negativo para conversão alimentar. Verificou-se que a utilização de dietas com níveis protéicos crescentes não influenciou o consumo de matéria seca dos cordeiros. Observou-se viabilidade econômica na terminação de cordeiros, utilizando-se dietas entre 12 e 24% de PB, entretanto, o maior retorno foi obtido com a ração contendo 12% PB. Não houve efeito de sexo para os parâmetros analisados.

  8. Desempenho de cordeiros confinados, alimentados com dietas à base de torta de girassol

    Directory of Open Access Journals (Sweden)

    Deivison Novaes Rodrigues

    2013-04-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da inclusão da torta de girassol na dieta de cordeiros em confinamento sobre o desempenho produtivo dos animais. Utilizaram-se 40 cordeiros sem raça definida, não castrados, com peso médio inicial de 20,17±2,66 kg, alimentados com 0, 7, 14, 21 e 28% de torta de girassol na dieta (base seca. O experimento foi conduzido em delineamento de blocos ao acaso. A inclusão de torta de girassol na dieta não alterou o consumo médio de matéria seca (883,58 g por dia, a conversão alimentar (4,40 e o consumo médio de água (2,59 L por dia. O aumento dos níveis de torta de girassol diminuiu linearmente o peso final, o ganho de peso total, o ganho de peso diário e a área de olho de lombo. O nível de inclusão de até 28% não afeta o consumo médio de matéria seca e de água, mas reduz o desempenho e a área de olho de lombo. Para obter o menor custo com a dieta, o nível de inclusão da torta de girassol pode atingir até 28% da matéria seca, quando o seu preço representar até 40% do preço da mistura entre milho e farelo de soja.

  9. Addendum to Microalgae Culture Collection 1986-1987

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, J. R.; Lemke, P.; Nagle, N. J.; Chelf, P.; Roessler, P. G.; Galloway, R.; Toon, S.

    1987-12-01

    The SERI Microalgae Culture Collection was established in support of the U.S. Department of Energy Biofuels and Municipal Waste Technology Program to provide a repository for strains identified or developed for mass culture biomass production.

  10. Extremophilic micro-algae and their potential contribution in biotechnology.

    Science.gov (United States)

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

    2015-05-01

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

  11. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae.

    NARCIS (Netherlands)

    Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

    2013-01-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments. Cyanobacteria are promising host organisms fo

  12. Collection and Screening of Microalgae for Lipid Production

    Energy Technology Data Exchange (ETDEWEB)

    Cooksey, K. E.

    1987-05-01

    Themotolerant microalgae were selected from an existing culture collection and isolated from hot spring areas of Yellowstone National Park. Several of them grew at 35 degrees celsius, although only one grew at much better than 1 doubling per day.

  13. Lipid releasing characteristics of microalgae species through continuous ultrasonication.

    Science.gov (United States)

    Natarajan, Ramya; Ang, Wei Ming Russell; Chen, Xue; Voigtmann, Michael; Lau, Raymond

    2014-04-01

    In this study, the lipid releasing characteristics of several microalgae species through continuous ultrasonication was examined. Two marine microalgae species, Tetraselmis suecica and Nannochloropsis sp., and one freshwater species, Chlorella sp. were ultrasonicated directly after cultivation. The cell disruption efficiency and lipids releasing pattern from microalgae cells were measured under various ultrasonication conditions. It was found that cell disruption efficiency correlates well with ultrasonication energy consumption despite the ultrasonication conditions. Lipids in Chlorella sp. that has rigid cell walls were released to the aqueous phase after cell disruption. T. suecica and Nannochloropsis sp. that have flexible cell membranes tend to coil up and retain the membrane lipids after disruption. Continuous ultrasonication can be a potential method to release the lipids in rigid walled microalgae species without expensive dewatering steps.

  14. Enrichment of bioactive compounds in microalgae for aquaculture

    OpenAIRE

    Fernandes, Tomásia Micaela Gomez

    2015-01-01

    Microalgae are promising microorganisms for the production of food and fine chemicals. Several species of microalgae are used in aquaculture with the purpose of transfer bioactive compounds up to the aquatic food chain. The main objective of this project was to develop a stress–inducement strategy in order to enhance the biochemical productivity of Nannochloropsis gaditana, Rhodomonas marina and Isochrysis sp. for aquaculture purposes having in account their growth and organizational differen...

  15. Biodiesel de microalgas: avanços e desafios

    Directory of Open Access Journals (Sweden)

    André Luiz Custódio Franco

    2013-01-01

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

  16. An integrated approach to microalgae biomass generation and processing

    OpenAIRE

    2016-01-01

    Liquid combustible fossil fuel empowers global society, yet is a non-renewable entity with time-constrained limits to supply. Advanced generation biofuel derived from microalgae could feasibly yield more than conventional biofuel crops, utilise non-agricultural land or the sea and remediate atmospheric carbon dioxide and anthropogenic waste. However, technical and economical limits have so far prevented the successful implementation of microalgae biofuels. This thesis exempl...

  17. DEVELOPMENT OF REFINERY CO2 CAPTURE BY MICROALGAE

    OpenAIRE

    Keresztényi, István; Babos, Katalin; Bohács, György; Siklósi, Tamás

    2013-01-01

    As a significant emitter of carbon-dioxide in the region MOL Hungarian Oil & Gas Plc. has launched an extensive research program associated with carbon capture and utilization. Research is focused on the utilization of carbon dioxide as a feedstock for biological processes such as greenhouse growing and microalgae cultivation for further industrial applications. For the development of microalgae related technologies MOL Downstream Development has established collaboration with several scienti...

  18. Microalgae as Sustainable Renewable Energy Feedstock for Biofuel Production

    OpenAIRE

    2015-01-01

    The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technical...

  19. Microalgae-microbial fuel cell: A mini review.

    Science.gov (United States)

    Lee, Duu-Jong; Chang, Jo-Shu; Lai, Juin-Yih

    2015-12-01

    Microalgae-microbial fuel cells (mMFCs) are a device that can convert solar energy to electrical energy via biological pathways. This mini-review lists new research and development works on microalgae processes, microbial fuel cell (MFC) processes, and their combined version, mMFC. The substantial improvement and technological advancement are highlighted, with a discussion on the challenges and prospects for possible commercialization of mMFC technologies.

  20. Microalgae as Sustainable Renewable Energy Feedstock for Biofuel Production

    Directory of Open Access Journals (Sweden)

    Srikanth Reddy Medipally

    2015-01-01

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

  1. Microalgae - A promising tool for heavy metal remediation.

    Science.gov (United States)

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

    2015-03-01

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

  2. Microalgae as sustainable renewable energy feedstock for biofuel production.

    Science.gov (United States)

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

    2015-01-01

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

  3. Review Paper on Cell Membrane Electroporation of Microalgae using Electric Field Treatment Method for Microalgae Lipid Extraction

    Science.gov (United States)

    Joannes, C.; Sipaut, C. S.; Dayou, J.; Yasir, S. M.; Mansa, R. F.

    2015-04-01

    The paper reviews the recent studies on the lipid extraction of microalgae that mainly highlighted on the cell disruption method using variety of microalgae species. Selection of cell disruption method and devices are crucial in order to achieve the highest extraction percentage of lipid and other valuable intracellular (proteins, carotenoids and chlorophylls) from microalgae cell. Pulsed electric field (PEF) and electrochemical lysis methods were found to be potential for enhancing the extraction efficiencies either conducted in single step extraction or used as pre-treatment followed by conventional extraction method. The PEF technology capable to extract lipid as high as 75%. While, electrochemical lysis treatment capable to extract lipid approximately 93% using Stainless Steel (SS) and Ti/IrO2 as the cathode and anode electrode respectively. PEF technology and electrochemical lysis are still considered to be a new method for microalgae lipid extraction and further investigation can still be done for better improvement of the system.

  4. Methane production from marine microalgae Isochrysis galbana.

    Science.gov (United States)

    Santos, Nathalia O; Oliveira, Suzana M; Alves, Larissa C; Cammarota, Magali C

    2014-04-01

    Methane production from marine microalgae Isochrysis galbana was assessed before and after mechanical and chemical pretreatments. Mechanical pretreatment resulted in a 61.7% increase in soluble Chemical Oxygen Demand. Different hydrolysis conditions were evaluated by varying temperature - T, sulfuric acid concentration - AC and biomass suspension concentration (measured as particulate COD - CODp) using an experimental design. The most significant interaction occurred between AC and T and the hydrolysis condition that showed the best result in the anaerobic digestion step was the condition at 40°C with addition of 0.2% (v/v) acid for 16h (9.27LCH4/kgVS). The low methane yields were attributed to inhibitory sodium concentrations for anaerobic digestion. Eliminating inhibitory sodium in the anaerobic digestion by biomass prewashing, there was a 71.5% increase in methane yield for biomass after acid hydrolysis, demonstrating the need for pretreatment and reduction in sodium concentration in the anaerobic digestion.

  5. Cultivation of microalgae in industrial wastewaters

    DEFF Research Database (Denmark)

    van Wagenen, Jonathan Myerson

    cultivation. When algae are grown within a wastewater treatment plant, the use of the chemical energy stored in the organic carbon dissolved in the wastewater could also be a useful option. Conventional aerobic sewage treatment expends much energy in breaking down the biomass to CO2. However, various......Microalgae production for the purpose of clearing wastewater has been researched for at least half a century. Such systems have a dual benefit: first, they prevent nutrients from entering water bodies and causing eutrophication; second, they transform sunlight and carbon dioxide into a biomass...... that has many potential uses. Unfortunately, the current high costs of cultivation have limited the development and exploitation of such systems, resulting in only a few full-scale algae wastewater treatment installations and a small industry based mostly around food and pigments. This thesis contributes...

  6. Used water resource recovery using green microalgae

    DEFF Research Database (Denmark)

    Wágner, Dorottya Sarolta

    A paradigm shift is promoted in wastewater treatment whereby wastewater is considered as a source of nutrients, water and energy, rather than waste and it is referred to as used water. Microalgae cultivation on used water resources offers the potential to recover nitrogen, phosphorus, water...... resources promoting sustainable urban water management. The system consists of a low solids retention time (SRT) enhanced biological phosphorus removal and recovery (EBP2R) system that can provide optimal cultivation medium – in terms of nutrients and water – for downstream microalgal cultivation...... is to develop a consensus-based microalgal process model (ASM-A) accounting for photoautotrophic and heterotrophic microalgal growth, the uptake and storage of nitrogen and phosphorus and decay. The model was developed in the ASM framework as an extension to ASM-2d, thus it can be readily connected to bacterial...

  7. Desempenho de bezerros alimentados usando de sucedâneo até 56 dias de idade

    Directory of Open Access Journals (Sweden)

    Silvia Resende de Albuquerque França

    2011-12-01

    Full Text Available Trinta bezerros machos da raça Holandesa foram alojados em piquetes a partir do quinto dia de vida, distribuídos em dois grupos. Todos os animais foram alimentados com concentrado comercial peletizado, tendo o primeiro grupo recebido leite integral (grupo-controle e o outro, sucedâneo formulado com proteínas de soja, de soro de leite e de leite desnatado em pó (grupo tratamento, num único horário de fornecimento, até 56 dias de vida. Os animais tinham acesso ad libitum à água e ao sal mineral. Suas medidas de peso vivo e altura de ísquio foram tomadas semanalmente. O desenvolvimento em estatura não diferiu entre os tratamentos, e o ganho em peso foi inferior para os animais alimentados com sucedâneo. O menor ganho em peso foi influenciado pelo menor consumo de concentrado e de matéria seca da dieta.

  8. Combining urban wastewater treatment with biohydrogen production--an integrated microalgae-based approach.

    Science.gov (United States)

    Batista, Ana Paula; Ambrosano, Lucas; Graça, Sofia; Sousa, Catarina; Marques, Paula A S S; Ribeiro, Belina; Botrel, Elberis P; Castro Neto, Pedro; Gouveia, Luisa

    2015-05-01

    The aim of the present work was the simultaneous treatment of urban wastewater using microalgae and the energetic valorization of the obtained biomass. Chlorella vulgaris (Cv), Scenedesmus obliquus (Sc) and a naturally occurring algal Consortium C (ConsC) were grown in an urban wastewater. The nutrient removals were quite high and the treated water fits the legislation (PT Dec-Lei 236/98) in what concerns the parameters analysed (N, P, COD). After nutrient depletion the microalgae remained two more weeks in the photobioreactor (PBR) under nutritional stress conditions, to induce sugar accumulation (22-43%). The stressed biomass was converted into biohydrogen (bioH2), a clean energy carrier, through dark fermentation by a strain of the bacteria Enterobacter aerogenes. The fermentation kinetics were monitored and fitted to a modified Gompertz model. The highest bioH2 production yield was obtained for S. obliquus (56.8 mL H2/gVS) which was very similar when using the same algae grown in synthetic media.

  9. Lipid extraction of wet BLT0404 microalgae for biofuel application

    Science.gov (United States)

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

    2017-01-01

    Recently, research and development of microalgae for biodiesel production were conducted by researchers in the world. This research becomes popular because of an exponential growth of the microalgae under nutrient limitation. Lipid of microalgae grows faster than oil producing land crops. Therefore, microalgae lipid content could improve the economics of biodiesel production. The aim of this study was to investigate yield of lipid extract and chemicals compounds containing in non-acylglycerol neutral lipid from BLT 0404 microalga. The study was conducted because lipid extraction was an important step for biodiesel as well as biofuel production. The extraction was carried out using polar and non-polar mixture solvents. The polar solvent was methanol and non-polar one was chloroform. Process extraction was conducted under various stirring time between the microalgae and methanol and volume ratio between the methanol and chloroform. Methanol as a polar solvent was able to extract polar lipid (phospholipid and glycolipid) because it removed polar membrane lipid and lipid-associated to polar molecule. Moreover, the non-polar solvent was used for extraction non-acylglycerol neutral lipid (hydrocarbons, sterols, ketones, free fatty acids, carotenes, and chlorophylls) for biofuel production. Under ratio of microalgae: methanol: chloroform of 0.8: 4: 2 that stirring time of the microalgae with methanol was 30 min yielded 58% of total lipid extract. The yield value consisted of 14.5% of non-acylglycerol neutral lipid and 43.5% of polar lipid. The non-acylglycerol neutral lipid will be converted into biofuel. Therefore, analysis of its chemical compounds was required. The non-acylglycerol neutral lipid was analyzed by GCMS and found that the extract contained long chains of hydrocarbon compounds. The hydrocarbons consisted of C18-C30 that high peaks with larger percentage area were C20-C26. The results suggested that stirring between microalgae and methanol for 30 min was

  10. Estudo comparativo do ciclo evolutivo de Rhodnius neglectus alimentados em pombos ou camundongos

    Directory of Open Access Journals (Sweden)

    Liléia Diotaiuti

    1987-06-01

    Full Text Available Baseados no encontro de 77,2% de reação de precipitina positiva para soro antiave de R. neglectus capturados em palmeiras da periferia de Belo Horizonte, estudamos o ciclo evolutivo de uma colonia recém-estabelecida no laboratório alimentada com sangue de pombo ou camundongo, na expectativa de demonstrarmos maior adaptação deste triatomíneo ao sangue da ave. Para comparação, estudamos o ciclo evolutivo destes insetos numa colônia há muito mantida em insetário. Nossos resultados mostram um desenvolvimento mais rápido da colônia recém- estabelecida, assim como do lote de triatomíneos alimentado em camundongo. Esses achados sugerem menor potencial biológico para triatomíneos criados por longo tempo em insetário em comparação a novas colônias. Sendo as aves os principais habitantes das palmeiras, a aparente preferência alimentar por sangue de aves demonstrada pela reação de precipitina parece ser circunstancial e não seletiva na busca do sangue com o qual o triatomíneo obteria melhor desenvolvimento.Feeding pattems of R. neglectus collected in palm trees around Belo Horizonte (Minas Gerais, Brazil were investigated. Precipitin tests showed 77.2% of avian blood. In view of these results, a new colony of R. neglectus established in the laboratory was fed regularly on pigeons or mice, in order to verify a possible better adaptation of this insect to the avian blood. As a control group a colony of R neglectus which has been maintained for several years in the laboratory was also observed. The results show a better development of the “new" colony in comparison with the old one, and of those bugs nourished with mice blood. Such findings suggest a poorer biological potential for triatomines maintained for long time in artificial conditions, in comparison with those living in the natural environment. As birds are the main vertebrate inhabitants of palm trees (the natural ecotope of R neglectus, the apparent feeding preference of

  11. IMPLEMENTACIÓN DE UN SISTEMA DE ALIMENTACIÓN ININTERRUMPIDA, CON VISUALIZACIÓN DE PARÁMETROS ELÉCTRICOS EN LCD

    Directory of Open Access Journals (Sweden)

    Franklin Giovanni Parra

    2013-07-01

    Full Text Available Este artículo presenta el diseño y la implementación de un sistema de alimentación ininterrumpida (UPS con visualización de parámetros eléctricos (tensión, corriente y potencia en una pantalla de cristal líquido (LCD, realizado mediante procesos lógico-matemáticos programados en un microcontrolador, con el fin de brindar alimentación constante a una carga crítica y a su vez conocer el comportamiento de las variables eléctricas del dispositivo que requiera ser alimentado.

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

    OpenAIRE

    Alexey Llopiz

    2016-01-01

    Cyanobacteria and microalgae are source of many chemicals substances with potential applications on biopharmaceutical industry. Many structures have been characterized in these organism, such as: peptides, proteins, carbohydrates, terpenoids, polyinsatured fatty acids, flavonoids, phenolic compounds, vitamins, porfirins and other organic substances. Chemicals structures of isolated compounds are diverse and it depends of microalgae habitats. Pharmacological activities located in microalga...

  13. Nutrient Acquisition: The Generation of Bioactive Vitamin B12 by Microalgae.

    Science.gov (United States)

    Grossman, Arthur

    2016-04-25

    Many microalgae acquire vitamin B12 from marine prokaryotes. A new study demonstrates that vitamin B12 is synthesized by planktonic cyanobacteria as pseudocobalamin, a form not bioactive in microalgae. However, some microalgae can remodel pseudocobalamin to the active cobalamin form, adding complexity to our assessment of active vitamin B12 in the environment.

  14. Patterns of sand fractions influence on microalgae of the marine coast

    Directory of Open Access Journals (Sweden)

    Anastasiya Snigirova

    2015-04-01

    Full Text Available To study effect of grain size on microalgae a new method is proposed: sand of different fractions is glued to the surface of microscope slides. Microalgae abundance was higher on fine sand grains (<0,25 mm. To forecast microalgae abundance the pattern is proposed depending on size of sand grains. 

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  16. Microalgas, produtos e aplicações Microalgae, products and applications

    Directory of Open Access Journals (Sweden)

    Roberto Bianchini Derner

    2006-12-01

    Full Text Available Nos últimos anos, muito interesse tem sido focado no potencial biotecnológico das microalgas, principalmente devido à identificação de diversas substâncias sintetizadas por estes organismos. A imensa biodiversidade e conseqüente variabilidade na composição bioquímica da biomassa obtida das culturas microalgais, aliadas ao emprego de melhoramento genético e ao estabelecimento de tecnologia de cultivo em grande escala, vêm permitindo que determinadas espécies sejam comercialmente utilizadas. Nesse sentido, cultivos de microalgas têm sido realizados visando à produção de biomassa tanto para uso na elaboração de alimentos quanto para a obtenção de compostos naturais com alto valor no mercado mundial. Dentre os inúmeros compostos extraídos, ou com potencial de exploração comercial, podem ser relacionados ácidos graxos poliinsaturados, carotenóides, ficobilinas, polissacarídeos, vitaminas, esteróis e diversos compostos bioativos naturais (antioxidantes, redutores do colesterol etc., os quais podem ser empregados especialmente no desenvolvimento de alimentos funcionais, por suas propriedades nutricionais e farmacêuticas.In recent years, much interest has been focused on the biotechnological potential of microalgae, mainly due the identification of several substances synthesized by these organisms. The great biodiversity and consequent variability in the biochemical composition of the biomass obtained from the microalgal cultures, allied to the genetic improvement and to the establishment of technology in massive production, have allowed various species to be commercially cultivated. In this sense, microalgae cultivations have been developed aiming at the biomass production not only for use in the food elaboration but also for the obtainment of natural compounds with high value in the world market. Among the main extracted substances, or with potential of commercial exploration, can be related polyunsaturated fatty acids

  17. Benefits of Microalgae for Human Space Exploration

    Science.gov (United States)

    Verrecchia, Angelique; Bebout, Brad M.; Murphy, Thomas

    2015-01-01

    Algae have long been known to offer a number of benefits to support long duration human space exploration. Algae contain proteins, essential amino acids, vitamins, and lipids needed for human consumption, and can be produced using waste streams, while consuming carbon dioxide, and producing oxygen. In comparison with higher plants, algae have higher growth rates, fewer environmental requirements, produce far less "waste" tissue, and are resistant to digestion and/or biodegradation. As an additional benefit, algae produce many components (fatty acids, H2, etc.) which are useful as biofuels. On Earth, micro-algae survive in many harsh environments including low humidity, extremes in temperature, pH, and as well as high salinity and solar radiation. Algae have been shown to survive inmicro-gravity, and can adapt to high and low light intensity while retaining their ability to perform nitrogen fixation and photosynthesis. Studies have demonstrated that some algae are resistant to the space radiation environment, including solar ultraviolet radiation. It remains to be experimentally demonstrated, however, that an algal-based system could fulfil the requirements for a space-based Bioregenerative Life Support System (BLSS) under comparable spaceflight power, mass, and environmental constraints. Two specific challenges facing algae cultivation in space are that (i) conventional growth platforms require large masses of water, which in turn require a large amount of propulsion fuel, and (ii) most nutrient delivery mechanisms (predominantly bubbling) are dependent on gravity. To address these challenges, we have constructed a low water biofilm based bioreactor whose operation is enabled by capillary forces. Preliminary characterization of this Surface Adhering BioReactor (SABR) suggests that it can serve as a platform for cultivating algae in space which requires about 10 times less mass than conventional reactors without sacrificing growth rate. Further work is necessary to

  18. Isolation, identification and characterization of an electrogenic microalgae strain.

    Science.gov (United States)

    Wu, Yicheng; Guan, Kai; Wang, Zejie; Xu, Bing; Zhao, Feng

    2013-01-01

    Extracellular electron transfer involving microbes is important as it closely reflects the ability of cells to communicate with the environment. However, there are few reports on electron transfer mechanisms of pure microalgae and a lack of any model alga to study the transfer processes. In the present study, nine green microalgae species were isolated from wastewater and characterized in terms of their ability to transfer electrons between cells and an electrode. One species showed direct electron transfer via membrane-associated proteins and indirect electron transfer via secreted oxygen. The microalga was identified as Desmodesmus sp. based on phylogenetic analysis and electron microscopy. Electrochemical tests demonstrated that Desmodesmus sp. was able to act as a cathodic microorganism. Stable current densities of -0.24, 35.54 and 170 mA m(-2) were achieved at potentials of +0.2, -0.2 and -0.4 V, respectively, under illumination. Dissolved oxygen concentration measurement showed gradients within the microalgae biofilm: 18.3 mg L(-1) in light decreasing to 4.29 mg L(-1) in the dark. This study diversified the exoelectrogen library and provided a potential model microalga to explore the associated mechanism of extracellular electron transfer.

  19. Applications of microfluidics in microalgae biotechnology: A review.

    Science.gov (United States)

    Juang, Yi-Je; Chang, Jo-Shu

    2016-03-01

    Microalgae have been one of the important sources for biofuel production owing to their competitive advantages such as no need to tap into the global food supply chain, higher energy density, and absorbing carbon dioxide to mitigate global warming. One of the key factors to ensure successful biofuel production is that it requires not only bioprospecting of the microalgae with high lipid content, high growth rate and tolerance to environmental parameters but also on-site monitoring of the cultivation process and optimization of the culturing conditions. However, as the conventional techniques usually involve in complicated procedures, or are time-consuming or labor intensive, microfluidics technology offers an attractive alternative to resolve these issues. In this review, applications of microfluidics to bioprospecting in microalgae biotechnology were discussed such as cell identification, cell sorting/screening, cell culturing and cell disruption. In addition, utilization of microalgae in micro-sized fuel cells and microfluidic platforms for biosensing was addressed. This review reports the recent studies and offers a look into how microfluidics is exploited to tackle the issues encountered in the microalgae biotechnology.

  20. Isolation, identification and characterization of an electrogenic microalgae strain.

    Directory of Open Access Journals (Sweden)

    Yicheng Wu

    Full Text Available Extracellular electron transfer involving microbes is important as it closely reflects the ability of cells to communicate with the environment. However, there are few reports on electron transfer mechanisms of pure microalgae and a lack of any model alga to study the transfer processes. In the present study, nine green microalgae species were isolated from wastewater and characterized in terms of their ability to transfer electrons between cells and an electrode. One species showed direct electron transfer via membrane-associated proteins and indirect electron transfer via secreted oxygen. The microalga was identified as Desmodesmus sp. based on phylogenetic analysis and electron microscopy. Electrochemical tests demonstrated that Desmodesmus sp. was able to act as a cathodic microorganism. Stable current densities of -0.24, 35.54 and 170 mA m(-2 were achieved at potentials of +0.2, -0.2 and -0.4 V, respectively, under illumination. Dissolved oxygen concentration measurement showed gradients within the microalgae biofilm: 18.3 mg L(-1 in light decreasing to 4.29 mg L(-1 in the dark. This study diversified the exoelectrogen library and provided a potential model microalga to explore the associated mechanism of extracellular electron transfer.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-08-01

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

  2. Low-cost harvesting of microalgae biomass from water

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    Bejor, E.S.

    2013-03-01

    Full Text Available Microalgae harvesting is known to be a major problem in the water industry. This is attributed to the minute nature of the algae cells and the often low concentration of the species in water and wastewater. While various chemical and mechanical harvesting techniques have been developed for algae harvesting, their application have been limited by prohibitive costs. There is also the disadvantage of not utilising the harvested microalgae as feedstock when it has accumulated significant amounts of chemicals (coagulants employed during the harvesting operation. This work investigates the low cost harvesting of microalgae biomass from water using physical (non-chemical method. Four fabric filters: stretch-cotton, polyester-linen, satin-polyester and silk were investigated to determine their microalgae harvesting efficiencies using filtration method on three algae communities with cell size of 2- 20 µm. For the three algae communities investigated, stretch-cotton filter showed a harvesting efficiency of 66- 93%, followed by polyester-linen (54- 90%, while satin-polyester and silk fabrics achieved harvesting efficiencies of 43- 71% and 27- 75% respectively. The research revealed that for wastewater generation of 1500m3/day and algae concentration of 200mg/l, microalgae harvesting cost per sq. meter per kg of algae per cubic meter would be ≤ £0.15 using stretch cotton filter

  3. Extracellular Metabolites from Industrial Microalgae and Their Biotechnological Potential

    Science.gov (United States)

    Liu, Lu; Pohnert, Georg; Wei, Dong

    2016-01-01

    Industrial microalgae, as a big family of promising producers of renewable biomass feedstock, have been commercially exploited for functional food, living feed and feed additives, high-value chemicals in nutraceuticals, cosmeceuticals, and chemical reagents. Recently, microalgae have also been considered as a group that might play an important role in biofuel development and environmental protection. Almost all current products of industrial microalgae are derived from their biomass; however, large amounts of spent cell-free media are available from mass cultivation that is mostly unexploited. In this contribution we discuss that these media, which may contain a remarkable diversity of bioactive substances are worthy to be recovered for further use. Obviously, the extracellular metabolites from industrial microalgae have long been neglected in the development of production methods for valuable metabolites. With the advances in the last ten years, more and more structures and properties from extracellular metabolites have been identified, and the potential utilization over wide fields is attracting attention. Some of these extracellular metabolites can be potentially used as drugs, antioxidants, growth regulators or metal chelators. The purpose of this review is to provide an overview of the known extracellular metabolites from industrial microalgae which might be of commercial interest. The attention mainly focuses on the reports of extracellular bioactive metabolites and their potential application in biotechnology. PMID:27775594

  4. Extracellular Metabolites from Industrial Microalgae and Their Biotechnological Potential

    Directory of Open Access Journals (Sweden)

    Lu Liu

    2016-10-01

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

  5. Nutrient and media recycling in heterotrophic microalgae cultures.

    Science.gov (United States)

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

    2016-02-01

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

  6. Papel inmunomodulador de las dietas lipídicas en un modelo murino inmunosuprimido e infectado con Listeria monocytogenes

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    José María Cerón Rodríguez

    Full Text Available Introducción: La capacidad inmunomoduladora de los ácidos grasos de la dieta en situaciones de inmunosupresión puede diferir de acuerdo con el tipo de ácido graso presente. Objetivo: Analizar el efecto de diferentes tipos de dietas lipídicas, en la resistencia de animales inmunosuprimidos o no, frente a una infección experimental con Listeria monocytogenes. Métodos: Ratones Balb/c fueron divididos en cuatro grupos experimentales, según su tratamiento inmunosupresor: control (PBS, Ciclofosfamida (CPA, GK 1.5 y RB6-8C5. Cada grupo fue subdividido en cuatro subgrupos según la dieta lipídica utilizada: control con aceite de maíz 5% (BG; aceite de oliva 20% (AO; aceite de pescado 20% (AP y aceite de girasol 20% (AG. Los animales se alimentaron durante un mes antes del tratamiento y posteriormente infectados con L. monocytogenes. Resultados: Mostramos incrementos en el número de bacterias viables en bazo e hígado, y bajos porcentajes de supervivencia en todos los grupos de ratones inmunosuprimidos y también en el grupo PBS alimentado con AP. Además, se observaron incrementos en la linfoproliferación, de bazos de ratones alimentados con AO y tratados con CPA. Discusión: La dieta AP, produce una disminución en la resistencia del hospedador en situaciones de inmunosupresión. Por el contrario, las dietas AO y AG muestran mayor eficacia en la eliminación de L. monocytogenes y mayores ventajas en animales inmunosuprimidos. El tratamiento con RB6-8C5, produce una reducción en la supervivencia de los ratones de los grupos estudiados, lo que induce a establecer que los granulocitos juegan un papel fundamental en el control de la infección.

  7. Estimación de Iluminación en un Fotobiorreactor Productor de Biomasa a Partir de Microalgas

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    Carlos Francisco González Hernández

    2014-01-01

    Full Text Available En el presente trabajo se realizó el análisis de iluminación artificial para un fotobiorreactor productor de biomasa a partir de microalgas, el cual fue diseñado previamente con fines en aplicación para la producción de biocombustibles. En el análisis, se utilizó como herramienta la técnica de contornos o también conocida como método de superficie de respuesta, para lo cual se establecieron 132 puntos de intensidad luminosa distribuidos de forma simétrica a diferentes alturas del contenedor. Se realizaron dos bioensayos uno con la iluminación en la parte inferior del recipiente usando Diodos Emisores de Luz (LED’s, por sus siglas en inglés y el otro adicionando 3 lámparas fluorescentes más, situadas periféricamente a la mitad de la altura total del fotobiorreactor. Los resultados de las mediciones muestran una mejoría en el sistema de iluminac ión que favorece la reproducción continua de las microalgas, cuando se utilizó la combinación de luz emitida por LED’s y por lámparas fluorescentes. Esta combinación de sistemas de iluminación generó las condiciones para poder realizar las funciones metabólicas de las microalgas, quienes necesitan en promedio 2500 lx de forma homogénea.

  8. Cultivo de las microalgas dulceacuícolas Kirchneriella obesa, Scenedesmus quadricauda y Chlorococcum infusorium empleando tres medios de cultivo

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    A. A. Ortega-Salas

    2012-01-01

    Full Text Available Se cultivaron las microalgas dulceacuícolas Kirchneriella obesa (G. S. West Schmidle 1893, Scenedesmus quadricauda (Chodat, Turpin Bréb 1835 y Chlorococcum infusorium (Schrank Meneghini 1842, con el propósito comparar las tasas de crecimiento y su rendimiento en tres medios de cultivo, el F/2 de Guillard, Fert I y Fert II. El agua utilizada se pasó en filtros de cinco, uno y 0.45 mm, y se trató con luz ultravioleta. La temperatura varió de 24 a 25°C. Se cultivaron en un sistema de volumen creciente a partir de recipientes de 62.5 mL, duplicando el medio de cultivo cada 24 h, con el fin de completar 32 L en nueve días. Cada 24 h se obtuvieron tres muestras de 1 a 10 mL del cultivo, se preservaron en una solución de lugol y se calculó la concentración de las microalgas cada 24 h. El número total de células de las tres especies aumentó de manera exponencial hasta el final de los experimentos en los medios de cultivo F/2 y Fert I; esto no fue así con el medio Fert II, en el cual la tasa de duplicación y el número total de divisiones fueron más bajas. El medio F/2 y el Fert I ofrecieron mejores resultados que el Fert II. Los medios Fert I y Fert II tienen un valor económico más bajo que el medio F/2. El crecimiento y el rendimiento fueron mejores con el medio F/2, seguido por FI y FII.

  9. Growth of microalgae in autotrophic stationary systems

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    Paulo Cunha

    2008-06-01

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

  10. Nitrogen Removal from Landfill Leachate by Microalgae

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    Sérgio F. L. Pereira

    2016-11-01

    Full Text Available Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N–NH4+ concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N–NH4+ concentration. In terms of nutrients uptake, an effective removal of N–NH4+ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N–NO3− removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates.

  11. Antioxidant activity of the microalga Spirulina maxima

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    M.S. Miranda

    1998-08-01

    Full Text Available Spirulina maxima, which is used as a food additive, is a microalga rich in protein and other essential nutrients. Spirulina contains phenolic acids, tocopherols and ß-carotene which are known to exhibit antioxidant properties. The aim of the present study was to evaluate the antioxidant capacity of a Spirulina extract. The antioxidant activity of a methanolic extract of Spirulina was determined in vitro and in vivo. The in vitro antioxidant capacity was tested on a brain homogenate incubated with and without the extract at 37oC. The IC50 (concentration which causes a 50% reduction of oxidation of the extract in this system was 0.18 mg/ml. The in vivo antioxidant capacity was evaluated in plasma and liver of animals receiving a daily dose of 5 mg for 2 and 7 weeks. Plasma antioxidant capacity was measured in brain homogenate incubated for 1 h at 37oC. The production of oxidized compounds in liver after 2 h of incubation at 37oC was measured in terms of thiobarbituric acid reactant substances (TBARS in control and experimental groups. Upon treatment, the antioxidant capacity of plasma was 71% for the experimental group and 54% for the control group. Data from liver spontaneous peroxidation studies were not significantly different between groups. The amounts of phenolic acids, a-tocopherol and ß-carotene were determined in Spirulina extracts. The results obtained indicate that Spirulina provides some antioxidant protection for both in vitro and in vivo systems.

  12. Microalgae culture collection, 1986-1987

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, W.; Johansen, J.; Chelf, P.; Nagle, N.; Roessler, P.; Lemke, P.

    1986-12-01

    The SERI Microalgae Culture Collection provides a repository for strains identified or developed for mass culture biomass production and makes these strains readily available to the research community. The strains in the collection have been selected for their potential in biomass fuel applications, and many produce significant quantities of cellular storage lipids. All of the newly added strains have been recently isolated by SERI and its subcontractors in organized screening programs. Many have been tested in outdoor mass culture systems, and several have demonstrated excellent performance as biomass producers. The strains added to the collection this year have been isolated from inland saline waters and marine waters. We believe that the strains in this collection can provide a source of extremely useful organisms, both for laboratory experimentation and for mass culture research. Most of the strains are currently nonaxenic. Again this year, cultures will be shipped free of charge to interested researchers. An important function of the culture collection catalog, in addition to listing the available strains, is to provide culture and performance data for each of the organisms. By collecting a summary of the requirements and characteristics of these organisms, we hope to allow requestors of cultures to begin productive research with a minimum of preliminary work on culture techniques.

  13. Gold nanoparticles produced in a microalga

    Science.gov (United States)

    Luangpipat, Tiyaporn; Beattie, Isabel R.; Chisti, Yusuf; Haverkamp, Richard G.

    2011-12-01

    An efficient biological route to production of gold nanoparticles which allows the nanoparticles to be easily recovered remains elusive. Live cells of the green microalga Chlorella vulgaris were incubated with a solution of gold chloride and harvested by centrifugation. Nanoparticles inside intact cells were identified by transmission electron microscopy and confirmed to be metallic gold by synchrotron based X-ray powder diffraction and X-ray absorption spectroscopy. These intracellular gold nanoparticles were 40-60 nm in diameter. At a concentration of 1.4% Au in the alga, a better than 97% recovery of the gold from solution was achieved. A maximum of 4.2% Au in the alga was obtained. Exposure of C. vulgaris to solutions containing dissolved salts of palladium, ruthenium, and rhodium also resulted in the production of the corresponding nanoparticles within the cells. These were surmised to be also metallic, but were produced at a much lower intracellular concentration than achieved with gold. Iridium was apparently toxic to the alga. No nanoparticles were observed using platinum solutions. C. vulgaris provides a possible route to large scale production of gold nanoparticles.

  14. Microalgae as bioreactors for bioplastic production

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    Steinbüchel Alexander

    2011-10-01

    Full Text Available Abstract Background Poly-3-hydroxybutyrate (PHB is a polyester with thermoplastic properties that is naturally occurring and produced by such bacteria as Ralstonia eutropha H16 and Bacillus megaterium. In contrast to currently utilized plastics and most synthetic polymers, PHB is biodegradable, and its production is not dependent on fossil resources making this bioplastic interesting for various industrial applications. Results In this study, we report on introducing the bacterial PHB pathway of R. eutropha H16 into the diatom Phaeodactylum tricornutum, thereby demonstrating for the first time that PHB production is feasible in a microalgal system. Expression of the bacterial enzymes was sufficient to result in PHB levels of up to 10.6% of algal dry weight. The bioplastic accumulated in granule-like structures in the cytosol of the cells, as shown by light and electron microscopy. Conclusions Our studies demonstrate the great potential of microalgae like the diatom P. tricornutum to serve as solar-powered expression factories and reveal great advantages compared to plant based production systems.

  15. Nitrogen Removal from Landfill Leachate by Microalgae

    Science.gov (United States)

    Pereira, Sérgio F. L.; Gonçalves, Ana L.; Moreira, Francisca C.; Silva, Tânia F. C. V.; Vilar, Vítor J. P.; Pires, José C. M.

    2016-01-01

    Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N–NH4+) concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus) removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N–NH4+ concentration. In terms of nutrients uptake, an effective removal of N–NH4+ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N–NO3− removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates. PMID:27869676

  16. Microalgae Culture Collection, 1985-1986

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    The SERI Microalgae Culture Collection was established in support of the US Department of Energy's Biofuels Program to provide a repository for strains identified or developed for mass culture biomass production and to make these strains readily available to the research community. The strains in the collection have been selected for their potential in biomass fuel applications, and many produce significant quantities of cellular storage lipids. The Culture Collection Catalog lists 20 strains of ten species. Many have been tested in outdoor mass culture systems, and several have demonstrated excellent performance as biomass producers, with yields of up to 40 grams of organic matter per square meter per day. The majority of strains added to the collection this year have been isolated from inland saline waters, although marine species are included as well. We believe that the strains in this collection can provide a source of extremely useful organisms, both for laboratory experimentation and for mass culture research. 98 refs., 31 figs., 52 tabs.

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

    Science.gov (United States)

    Luo, Xuan; Su, Peng; Zhang, Wei

    2015-07-09

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

  18. Cultivation Of Microalgae (Chlorella vulgaris For Biodiesel Production

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    Blinová Lenka

    2015-06-01

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

  19. Ultrasonic assisted biodiesel production of microalgae by direct transesterification

    Science.gov (United States)

    Kalsum, Ummu; Mahfud, Mahfud; Roesyadi, Achmad

    2017-03-01

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

  20. Cultivation Of Microalgae (Chlorella vulgaris) For Biodiesel Production

    Science.gov (United States)

    Blinová, Lenka; Bartošová, Alica; Gerulová, Kristína

    2015-06-01

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

  1. Treatment of drainage solution from hydroponic greenhouse production with microalgae.

    Science.gov (United States)

    Hultberg, Malin; Carlsson, Anders S; Gustafsson, Susanne

    2013-05-01

    This study investigated treatment of the drainage solution from greenhouse production with microalgae, through inoculation with Chlorella vulgaris or through growth of the indigenous microalgal community. A significant reduction in nitrogen, between 34.7 and 73.7 mg L(-1), and particularly in phosphorus concentration, between 15.4 and 15.9 mg L(-1), was observed in drainage solution collected from commercial greenhouse production. The large reduction in nutrients was achieved through growth of the indigenous microalgal community i.e., without pre-treatment of the drainage solution or inoculation with the fast growing green microalgae C. vulgaris. Analysis of the fatty acid composition of the algal biomass revealed that compared with a standard growth medium for green algae, the drainage solution was inferior for lipid production. Despite the biorefinery concept being less promising, microalgae-based treatment of drainage solution from greenhouse production is still of interest considering the urgent need for phosphorus recycling.

  2. Microalga propels along vorticity direction in a shear flow

    Science.gov (United States)

    Chengala, Anwar; Hondzo, Miki; Sheng, Jian

    2013-05-01

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

  3. A Holistic Approach to Managing Microalgae for Biofuel Applications

    Science.gov (United States)

    Show, Pau Loke; Tang, Malcolm S. Y.; Nagarajan, Dillirani; Ling, Tau Chuan; Ooi, Chien-Wei; Chang, Jo-Shu

    2017-01-01

    Microalgae contribute up to 60% of the oxygen content in the Earth’s atmosphere by absorbing carbon dioxide and releasing oxygen during photosynthesis. Microalgae are abundantly available in the natural environment, thanks to their ability to survive and grow rapidly under harsh and inhospitable conditions. Microalgal cultivation is environmentally friendly because the microalgal biomass can be utilized for the productions of biofuels, food and feed supplements, pharmaceuticals, nutraceuticals, and cosmetics. The cultivation of microalgal also can complement approaches like carbon dioxide sequestration and bioremediation of wastewaters, thereby addressing the serious environmental concerns. This review focuses on the factors affecting microalgal cultures, techniques adapted to obtain high-density microalgal cultures in photobioreactors, and the conversion of microalgal biomass into biofuels. The applications of microalgae in carbon dioxide sequestration and phycoremediation of wastewater are also discussed. PMID:28117737

  4. Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

    Directory of Open Access Journals (Sweden)

    Rui Manuel Santos Costa de Morais

    2013-01-01

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

  5. Bioactivity and applications of sulphated polysaccharides from marine microalgae.

    Science.gov (United States)

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

    2013-01-23

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

  6. A Holistic Approach to Managing Microalgae for Biofuel Applications

    Directory of Open Access Journals (Sweden)

    Pau Loke Show

    2017-01-01

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

  7. Sustainability and economic evaluation of microalgae grown in brewery wastewater.

    Science.gov (United States)

    Mata, Teresa M; Mendes, Adélio M; Caetano, Nídia S; Martins, António A

    2014-09-01

    This article evaluates the sustainability and economic potential of microalgae grown in brewery wastewater for biodiesel and biomass production. Three sustainability and two economic indicators were considered in the evaluation within a life cycle perspective. For the production system the most efficient process units were selected. Results show that harvesting and oil separation are the main process bottlenecks. Microalgae with higher lipid content and productivity are desirable for biodiesel production, although comparable to other biofuel's feedstock concerning sustainability. However, improvements are still needed to reach the performance level of fossil diesel. Profitability reaches a limit for larger cultivation areas, being higher when extracted biomass is sold together with microalgae oil, in which case the influence of lipid content and areal productivity is smaller. The values of oil and/or biomass prices calculated to ensure that the process is economically sound are still very high compared with other fuel options, especially biodiesel.

  8. Thermogravimetric analysis of the gasification of microalgae Chlorella vulgaris.

    Science.gov (United States)

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

    2015-12-01

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

  9. Effect of coagulant/flocculants on bioproducts from microalgae.

    Science.gov (United States)

    Anthony, Renil J; Ellis, Joshua T; Sathish, Ashik; Rahman, Asif; Miller, Charles D; Sims, Ronald C

    2013-12-01

    The potential of microalgae as a source of sustainable energy, nutritional supplements and specialized chemicals necessitates a thorough evaluation of the methods of harvesting microalgae with regards to the bioproduct(s) desired. This research assessed the effect of coagulation, flocculation, and centrifugation on the wet lipid extraction procedure, which fractionated microalgae into hydrolyzed biomass for fermentation into acetone, butanol, and ethanol, an aqueous phase as growth media for genetically engineered Escherichia coli, and a lipid fraction for the production of biodiesel. Biomass harvested by cationic starches, alum, and centrifugation produced 30, 19, and 22.5mg/g of dry wt. algae of total combined acetone, butanol, and ethanol, respectively. Higher biodiesel production was also observed for the cationic starches (9.6 mg/g of dry wt. algae) than alum (0.6 mg/g of dry wt. algae) harvested biomass. The results suggested significant effect of the harvesting methods on the yields of bioproducts.

  10. Microalgae Isolation and Selection for Prospective Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Peer M. Schenk

    2012-06-01

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

  11. Lipids rich in ω-3 polyunsaturated fatty acids from microalgae.

    Science.gov (United States)

    Santos-Sánchez, N F; Valadez-Blanco, R; Hernández-Carlos, B; Torres-Ariño, A; Guadarrama-Mendoza, P C; Salas-Coronado, R

    2016-10-01

    Despite microalgae recently receiving enormous attention as a potential source of biodiesel, their use is still not feasible as an alternative to fossil fuels. Recently, interest in microalgae has focused on the production of bioactive compounds such as polyunsaturated fatty acids (PUFA), which provide microalgae a high added value. Several considerations need to be assessed for optimizing PUFA production from microalgae. Firstly, a microalgae species that produces high PUFA concentrations should be selected, such as Nannochloropsis gaditana, Isochrysis galbana, Phaeodactylum tricornutum, and Crypthecodinium cohnii, with marine species gaining more attention than do freshwater species. Closed cultivation processes, e.g., photobioreactors, are the most appropriate since temperature, pH, and nutrients can be controlled. An airlift column with LEDs or optical fibers to distribute photons into the culture media can be used at small scale to produce inoculum, while tubular and flat panels are used at commercial scale. Depending on the microalgae, a temperature range from 15 to 28 °C and a pH from 7 to 8 can be employed. Relevant conditions for PUFA production are medium light irradiances (50-300 μmol photons m(-2) s(-1)), air enriched with (0-1 % (v/v) CO2, as well as nitrogen and phosphorous limitation. For research purposes, the most appropriate medium for PUFA production is Bold's Basal, whereas mixotrophic cultivation using sucrose or glucose as the carbon source has been reported for industrial processes. For cell harvesting, the use of tangential flow membrane filtration or disk stack centrifugation is advisable at commercial scale. Current researches on PUFA extraction have focused on the use of organic solvents assisted with ultrasound or microwaves, supercritical fluids, and electroporation or are enzyme assisted. Commercial-scale extraction involves mainly physical methods such as bead mills and expeller presses. All these factors should be taken into

  12. Microalgae as a raw material for biofuels production.

    Science.gov (United States)

    Gouveia, Luisa; Oliveira, Ana Cristina

    2009-02-01

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

  13. Non-photoautotrophic cultivation of microalgae: an overview

    Directory of Open Access Journals (Sweden)

    Elisangela Andrade Angelo

    2014-12-01

    Full Text Available Microalgae are a heterogeneous group of microorganisms that produces biomass from which can be extracted various products such as proteins, carbohydrates, pigments and oils with profile containing saturated fatty acids, polyunsaturated and monounsaturated. These microorganisms have different forms of energetic metabolism, especially the photoautotrophic, heterotrophic, and mixotrophic photoautotrophic. Understanding these metabolic forms allows to apply microalgae strategies of cultivation aiming to increase algal biomass production, and its co-products in large scales. Traditionally, the microalgae cultivation is done by exploiting their photoautotrophic metabolism. However, studies have point out some advantages in the production of biomass of these microorganisms by using other metabolic pathways. Thus, this review aims to present an overview of the forms of non-photoautotrophic microalgae metabolism and considerations on the different systems of biomass production of these microorganisms. In the heterotrophic metabolism, sources of carbon that have stood out the most for microalgae are: glucose, glycerol and acetic acid. Nevertheless, there are several studies that present alternative sources of culture medium, such as agro-industrial and sanitary waste. The mixotrophic can be defined as the metabolism when photosynthesis and oxidation of external organic carbon take place at the same time. In the photoherotrophic metabolism is the light energy source and the organic compound is a carbon source. The non-photoautotrophic cultivation systems are high potential, mainly for increasing production with better productivity and scaling up. However, it should be noted that information about these microalgae cultivation systems on a large scale for a competitive production is scarce.

  14. Biogas Production From Cassava Starch Effluent Using Microalgae As Biostabilisator

    Directory of Open Access Journals (Sweden)

    B. Budiyono

    2011-07-01

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

  15. PROPAGACIÓN DE LA MICROALGA Chlorella sp. EN CULTIVO POR LOTE: CINÉTICA DEL CRECIMIENTO CELULAR

    Directory of Open Access Journals (Sweden)

    Cherlys Infante

    2012-01-01

    Full Text Available En este trabajo, se estudia el crecimiento de Chlorella sp., un alga microscópica, ampliamente distribuida en aguas marinas, con el fin de observar su comportamiento en cultivo por lote. El diseño experimental contempló la obtención de la biomasa de la microalga, utilizando un medio preparado con sales inorgánicas. Se obtuvo información acerca de la reproducibilidad de los ensayos realizados, estableciendo que se trata de un microorganismo de fácil propagación. Este resultado a su vez posibilita la aplicación de la microalga a diferentes estrategias para la remoción de sustancias nocivas presentes en los ecosistemas. El cultivo por lotes resulta adecuado para la obtención de biomasa de Chlorella sp observándose un ajuste lineal para la cinética de crecimiento. Los resultados obtenidos son una contribución al proyecto de investigación en el área de biosorción, que actualmente se desarrolla en conjunto la Universidad de Cartagena y la Universidad del Atlántico (Colombia.

  16. Batch anaerobic co-digestion of waste activated sludge and microalgae (Chlorella sorokiniana) at mesophilic temperature.

    Science.gov (United States)

    Beltrán, Carolina; Jeison, David; Fermoso, Fernando G; Borja, Rafael

    2016-08-23

    The microalgae Chlorella sorokiniana are used as co-substrate for waste activated sludge (WAS) anaerobic digestion. The specific objective of this research was to evaluate the feasibility of improving methane production from anaerobic digestion of WAS in co-digestion with this microalga, based on an optimized mixture percentage. Thus, the anaerobic co-digestion of both substrates aims to overcome the drawbacks of the anaerobic digestion of single WAS, simultaneously improving its management. Different co-digestion mixtures (0% WAS-100% microalgae; 25% WAS-75% microalgae; 50% WAS-50% microalgae; 75% WAS-25% microalgae; 100% WAS-0% microalgae) were studied. The highest methane yield (442 mL CH4/g VS) was obtained for the mixture with 75% WAS and 25% microalgae. This value was 22% and 39% higher than that obtained in the anaerobic digestion of the sole substrates WAS and microalgae, respectively, as well as 16% and 25% higher than those obtained for the co-digestion mixtures with 25% WAS and 75% microalgae and 50% WAS and 50% microalgae, respectively. The kinetic constant of the process increased 42%, 42% and 12%, respectively, for the mixtures with 25%, 50% and 75% of WAS compared to the substrate without WAS. Anaerobic digestion of WAS, together with C. sorokiniana, has been clearly improved by ensuring its viability, suitability and efficiency.

  17. Comparison of direct and indirect pyrolysis of micro-algae Isochrysis.

    Science.gov (United States)

    Wang, Xin; Zhao, Bingwei; Tang, Xiaohan; Yang, Xiaoyi

    2015-03-01

    Yield and composition of pyrolysis oil in direct and indirect pyrolysis process were investigated which indicated that pyrolysis of defatted microalgae provided a potential way to convert protein and carbohydrate to biofuels. Defatted microalgae pyrolysis with lipid extraction has higher total oil yield than only microalgae direct pyrolysis. There was an increase for N-heterocyclic compounds and phenols and a decrease for hydrocarbons in defatted microalgae pyrolysis oil. There is an apparent decrease from C12 to C16 and nearly no carbon distribution from C17 to C22 for defatted microalgae pyrolysis. Based on composition of pyrolysis feedstock, pyrolysis oil yields were simulated by Compounds Biofuel Model and their accuracy was less than ±4.4%. Considering total oil yield and characteristics, microalgae pyrolysis after lipid extraction process is a promising way for microalgae utilization.

  18. Effects of bacterial communities on biofuel-producing microalgae: stimulation, inhibition and harvesting.

    Science.gov (United States)

    Wang, Hui; Hill, Russell T; Zheng, Tianling; Hu, Xiaoke; Wang, Bin

    2016-01-01

    Despite the great interest in microalgae as a potential source of biofuel to substitute for fossil fuels, little information is available on the effects of bacterial symbionts in mass algal cultivation systems. The bacterial communities associated with microalgae are a crucial factor in the process of microalgal biomass and lipid production and may stimulate or inhibit growth of biofuel-producing microalgae. In addition, we discuss here the potential use of bacteria to harvest biofuel-producing microalgae. We propose that aggregation of microalgae by bacteria to achieve >90% reductions in volume followed by centrifugation could be an economic approach for harvesting of biofuel-producing microalgae. Our aims in this review are to promote understanding of the effects of bacterial communities on microalgae and draw attention to the importance of this topic in the microalgal biofuel field.

  19. PRODUCCIÓN DE BIOCOMBUSTIBLES A PARTIR DE MICROALGAS

    OpenAIRE

    Luis Carlos Fernández-Linares; Jorge Montiel-Montoya; Aarón Millán-Oropeza; Jesús Agustín Badillo-Corona

    2012-01-01

    Se hace una revisión de la situación de los biocombustibles en el mundo, principalmente del biodiesel. Se comparan las diferentes materias primas para la síntesis de biodiesel y se enfatiza en la producción de éste a partir de microalgas. Se comparan las diferentes microalgas de agua dulce y salada en cuanto a su contenido lipídico y productividad. Se revisa el proceso de biosíntesis de los lípidos y como se puede mejorar su producción de lípidos en estas. Se discute la importancia de manipul...

  20. A quick colorimetric method for total lipid quantification in microalgae.

    Science.gov (United States)

    Byreddy, Avinesh R; Gupta, Adarsha; Barrow, Colin J; Puri, Munish

    2016-06-01

    Discovering microalgae with high lipid productivity are among the key milestones for achieving sustainable biodiesel production. Current methods of lipid quantification are time intensive and costly. A rapid colorimetric method based on sulfo-phospho-vanillin (SPV) reaction was developed for the quantification of microbial lipids to facilitate screening for lipid producing microalgae. This method was successfully tested on marine thraustochytrid strains and vegetable oils. The colorimetric method results correlated well with gravimetric method estimates. The new method was less time consuming than gravimetric analysis and is quantitative for lipid determination, even in the presence of carbohydrates, proteins and glycerol.

  1. Hydrolysis for direct esterification of lipids from wet microalgae.

    Science.gov (United States)

    Takisawa, Kenji; Kanemoto, Kazuyo; Miyazaki, Tatsuo; Kitamura, Yutaka

    2013-09-01

    Hydrolysis of lipids from microalgae under high water content was investigated as a pretreatment of direct esterification. Results indicated that the hydrolysis process reduced the inhibition by water in FAME production; in addition, FAME obtained by esterification of hydrolysates was increased by 181.7% compared to FAME obtained by direct transesterification under the same amount of water content (80%). This method has great potential in terms of biodiesel production from microalgae since it uses no organic solvent, reduces the drying cost and lowers the operating cost compared to any other traditional method.

  2. Biomass and biofuels from microalgae advances in engineering and biology

    CERN Document Server

    Moheimani, Navid Reza; de Boer, Karne; Bahri, Parisa

    2015-01-01

    This comprehensive book details the most recent advances in the microalgae biological sciences and engineering technologies for biomass and biofuel production in order to meet the ongoing need for new and affordable sources of food, chemicals and energy for future generations. The chapters explore new microalgae cultivation techniques, including solid (biofilm) systems, and heterotrophic production methods, while also critically investigating topics such as combining wastewater as a source of nutrients, the effect of CO2 on growth, and converting biomass to methane through anaerobi

  3. Biofuel production from microalgae as feedstock: current status and potential.

    Science.gov (United States)

    Han, Song-Fang; Jin, Wen-Biao; Tu, Ren-Jie; Wu, Wei-Min

    2015-06-01

    Algal biofuel has become an attractive alternative of petroleum-based fuels in the past decade. Microalgae have been proposed as a feedstock to produce biodiesel, since they are capable of mitigating CO2 emission and accumulating lipids with high productivity. This article is an overview of the updated status of biofuels, especially biodiesel production from microalgae including fundamental research, culture selection and engineering process development; it summarizes research on mathematical and life cycle modeling on algae growth and biomass production; and it updates global efforts of research and development and commercialization attempts. The major challenges are also discussed.

  4. USE OF BACTERIA AND MICROALGAE IN SYNTHESIS OF NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    Inga Zinicovscaia

    2012-12-01

    Full Text Available A critical need in the field of nanotechnology is the development of a reliable and eco-friendly process for synthesis of metallic nanoparticles. A number of different organisms, including bacteria, microalgae, yeast and fungi, have shown their ability to produce metal nanoparticles. But they have some drawbacks in providing better control over size distribution, shape and crystallinity. This review article presents an overview of microorganisms (bacteria and microalga capable of producing silver and gold nanoparticles. This article is an extended abstract of a communication presented at the Conference Ecological Chemistry 2012

  5. Microalgae for economic applications: advantages and perspectives for bioethanol.

    Science.gov (United States)

    Simas-Rodrigues, Cíntia; Villela, Helena D M; Martins, Aline P; Marques, Luiza G; Colepicolo, Pio; Tonon, Angela P

    2015-07-01

    Renewable energy has attracted significant interest in recent years as a result of sustainability, environmental impact, and socio-economic considerations. Given existing technological knowledge and based on projections relating to biofuels derived from microalgae, microalgal feedstock is considered to be one of the most important renewable energy sources potentially available for industrial production. Therefore, this review examines microalgal bioethanol technology, which converts biomass from microalgae to fuel, the chemical processes involved, and possible ways of increasing the bioethanol yield, such as abiotic factors and genetic manipulation of fermenting organisms.

  6. Potency of Microalgae as Biodiesel Source in Indonesia

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2012-04-01

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

  7. Potency of Microalgae as Biodiesel Source in Indonesia

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2012-02-01

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

  8. Estudio de macronutrientes para la producción de PUFAs a partir de la microalga marina Isochrysis galbana

    Directory of Open Access Journals (Sweden)

    García Sánchez, J. L.

    1994-10-01

    Full Text Available Marine microalgae are presented as alternative sources for polyunsaturated fatty acids production.
    A macronutrient optimization method for culture media commonly used for Isochrysis galbana growth is discussed. This microalga has been reported as a good RUFA producer.
    The optimization was conducted applying the response surface technique, parameters tested being nitrate, phosphate, ferric citrate and manganese chloride concentrations and the suplementary CO2 in the bubbling air.
    The results show the evidence of growth limitation with the initial culture media and it is proposed a second optimization step considering as design variables the different ratios between media components.

    Las microalgas marinas se presentan como una fuente altemativa en la producción de ácidos grasos poliinsaturados (PUFAs, frente a las fuentes convencionales, como son los aceites de pescado.
    En este trabajo se presenta un estudio de macronutrientes para el medio de cultivo utilizado en el crecimiento de la microalga marina Isochrysis galbana, empleada con este objetivo.
    La metodología de optimización aplicada ha sido la técnica de superficie de respuesta, siendo los factores estudiados el porcentaje de CO2 suplementario en la corriente de burbujeo, y las concentraciones de nitratos, fosfatos, citrato férrico y cloruro de manganeso en el medio de cultivo. Los resultados de este trabajo ponen de manifiesto la existencia de limitaciones al crecimiento con el medio de partida y orientan a una segunda etapa de optimización, tomando como variables de diseño las relaciones entre los distintos componentes del medio de cultivo.

  9. Detection of marine toxins using cell-based assays and Characterization of toxin profiles in ciguatera-related natural samples: microalgae and fish. / (Detección de toxinas marinas mediante ensayos celulares y Caracterización del perfil toxinico en muestras naturales asociadas a la ciguatera: microalgas y pescado

    OpenAIRE

    Caillaud, Amandine

    2011-01-01

    [spa] La eficacia de los ensayos con células de neuroblastoma (Neuro-2a) ha sido examinada para la caracterización del perfil toxínico en muestras naturales asociadas a la ciguatera: microalgas (Gambierdiscus spp. y Prorocentrum rhathymum) y muestras de pescado potencialmente ciguatóxico procedentes de las Islas Canarias. La eliminación de las interferencias de las matrices biológicas y la especificidad de los ensayos con células Neuro-2a para ciguatoxinas y maitotoxinas han sido dos aspectos...

  10. IDENTIFICACIÓN DE MICROALGAS OLEAGINOSAS EN EL ÁREA DE CONCESIÓN PARA CONSERVACIÓN, CUENCA ALTA DEL RÍO ITAYA. LORETO-PERÚ

    Directory of Open Access Journals (Sweden)

    Marianela Cobos Ruiz

    2012-12-01

    Full Text Available Las microalgas oleaginosas constituyen una nueva alternativa para la producción de biodiesel, por su alta eficiencia fotobiosintética de triglicéridos y presentan productividades mayores de 10 a 100 veces que los cultivos convencionales. Además que actúan como sumideros de CO2 y pueden usar aguas servidas para producir biodiesel. Sin embargo, los estudios sobre identificación de este tipo de microalgas en la amazonía son escasos. El objetivo del presente trabajo de investigación fue identificar especies de microalgas oleaginosas con potencial aplicación para la producción de biodiesel que se encuentran en ambientes acuáticos del Área de Concesión para Conservación de la Universidad Científica del Perú (UCP. La colecta de las muestras se realizó del 27/06/12 al 03/07/12 entre las 12 y 15 h utilizando red planctónica tipo cono y como preservante formol al 3%. La identificación microscópica se realizó en el Laboratorio de Ciencias Básicas de la UCP. La densidad de las microalgas fue realizada en base a su conteo en cámaras de Neubauer  y Sedgwick-Rafter. Los resultados muestran la presencia de 20 especies de microalgas, de las cuales cinco son microalgas oleaginosas. Correspondiente a las del género Chlorella quienes presentaron la mayor densidad promedio (6x104 células/ml en las tres cochas evaluadas.

  11. IDENTIFICACIÓN DE MICROALGAS OLEAGINOSAS EN EL ÁREA DE CONCESIÓN PARA CONSERVACIÓN, CUENCA ALTA DEL RÍO ITAYA. LORETO-PERÚ

    Directory of Open Access Journals (Sweden)

    Marianela Cobos Ruiz

    2012-12-01

    Full Text Available Las microalgas oleaginosas constituyen una nueva alternativa para la producción de biodiesel, por su alta eficiencia fotobiosintética de triglicéridos y presentan productividades mayores de 10 a 100 veces que los cultivos convencionales. Además, que actúan como sumideros de CO2 y pueden usar aguas servidas para producir biodiesel. Sin embargo, los estudios sobre identificación de este tipo de microalgas en la amazonía son escasos. El objetivo del presente trabajo de investigación fue identificar especies de microalgas oleaginosas con potencial aplicación para la producción de biodiesel que se encuentran en ambientes acuáticos del Área de Concesión para Conservación de la Universidad Científica del Perú (UCP. La colecta de las muestras se realizó del 27/06/12 al 03/07/12 entre las 12 y 15 h utilizando red planctónica tipo cono y como preservante formol al 3%. La identificación microscópica se realizó en el Laboratorio de Ciencias Básicas de la UCP. La densidad de las microalgas fue realizada en base a su conteo en cámaras de Neubauer y Sedgwick-Rafter. Los resultados muestran la presencia de 20 especies de microalgas, de las cuales cinco son microalgas oleaginosas. Correspondiente a las del género Chlorella quienes presentaron la mayor densidad promedio (6x104 células/ml en las tres cochas evaluadas.

  12. Ingestion of Brachionus plicatilis under different microalgae conditions

    Institute of Scientific and Technical Information of China (English)

    ZHOU Wenli; TANG Xuexi; QIAO Xiuying; WANG You; WANG Renjun; FENG Lei

    2009-01-01

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

  13. Phototrophic pigment production with microalgae: biological constraints and opportunities

    NARCIS (Netherlands)

    Mulders, K.J.M.; Lamers, P.P.; Martens, D.E.; Wijffels, R.H.

    2014-01-01

    There is increasing interest in naturally produced colorants, and microalgae represent a bio-technologically interesting source due to their wide range of colored pigments, including chlorophylls (green), carotenoids (red, orange and yellow), and phycobiliproteins (red and blue). However, the concen

  14. Whole cell hybridisation for monitoring harmful marine microalgae.

    Science.gov (United States)

    Toebe, Kerstin

    2013-10-01

    Fluorescence in situ hybridisation (FISH) is a powerful molecular biological tool to detect and enumerate harmful microorganism in the marine environment. Different FISH methods are available, and especially in combination with automated counting techniques, the potential for a routine monitoring of harmful marine microalgae is attainable. Various oligonucleotide probes are developed for detecting harmful microalgae. However, FISH-based methods are not yet regularly included in monitoring programmes tracking the presence of harmful marine microalgae. A limitation factor of the FISH technique is the currently available number of suited fluorochromes attached to the FISH probes to detect various harmful species in one environmental sample at a time. However, coupled automated techniques, like flow cytometry or solid-phase cytometry, can facilitate the analysis of numerous field samples and help to overcome this drawback. A great benefit of FISH in contrast to other molecular biological detection methods for harmful marine microalgae is the direct visualisation of the hybridised target cells, which are not permitted in cell free formats, like DNA depending analysis methods. Therefore, an additional validation of the FISH-generated results is simultaneously given.

  15. Microalgae for the production of bulk chemicals and biofuels

    NARCIS (Netherlands)

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

    2010-01-01

    The feasibility of microalgae production for biodiesel was discussed. Although algae are not yet produced at large scale for bulk applications, there are opportunities to develop this process in a sustainable way. It remains unlikely, however, that the process will be developed for biodiesel as the

  16. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae

    NARCIS (Netherlands)

    Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

    2013-01-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments.Cyanobacteria are promising host organisms for

  17. Combustion of Microalgae Oil and Ethanol Blended with Diesel Fuel

    Directory of Open Access Journals (Sweden)

    Saddam H. Al-lwayzy

    2015-12-01

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

  18. Ingestion of Brachionus plicatilis under different microalgae conditions

    Science.gov (United States)

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

    2009-09-01

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

  19. Anaerobic biodegradation of lipids of the marine microalga Nannochloropsis salina

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Grossi, V.; Blokker, P.

    2001-01-01

    In order to determine the susceptibility to anaerobic biodegradation of the different lipid biomarkers present in a marine microalga containing algaenan, portions of one large batch of cultured Nannochloropsis salina (Eustigmatophyceae) were incubated in anoxic sediment slurries for various times. A

  20. Laboratory sulfurisation of the marine microalga Nannochloropsis salina

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Gelin, F.; Kok, M.D.; Leeuw, J.W. de

    1998-01-01

    To understand more fully the mode of preservation of organic matter in marine sediments, laboratory sulfurisation of intact cells of the cultured microalga Nannochloropsis salina was performed using inorganic polysulfides in seawater at 50°C. Solvent extractable and non-extractable materials were an

  1. Insecticides induced biochemical changes in freshwater microalga Chlamydomonas mexicana.

    Science.gov (United States)

    Kumar, Muthukannan Satheesh; Kabra, Akhil N; Min, Booki; El-Dalatony, Marwa M; Xiong, Jiuqiang; Thajuddin, Nooruddin; Lee, Dae Sung; Jeon, Byong-Hun

    2016-01-01

    The effect of insecticides (acephate and imidacloprid) on a freshwater microalga Chlamydomonas mexicana was investigated with respect to photosynthetic pigments, carbohydrate and protein contents, fatty acids composition and induction of stress indicators including proline, superoxide dismutase (SOD) and catalase (CAT). C. mexicana was cultivated with 1, 5, 10, 15, 20 and 25 mg L(-1) of acephate and imidacloprid. The microalga growth increased with increasing concentrations of both insecticides up to 15 mg L(-1), beyond which the growth declined compared to control condition (without insecticides). C. mexicana cultivated with 15 mg L(-1) of both insecticides for 12 days was used for further analysis. The accumulation of photosynthetic pigments (chlorophyll and carotenoids), carbohydrates and protein was decreased in the presence of both insecticides. Acephate and imidacloprid induced the activities of superoxide dismutase (SOD) and catalase (CAT) and increased the concentration of proline in the microalga, which play a defensive role against various environmental stresses. Fatty acid analysis revealed that the fraction of polyunsaturated fatty acids decreased on exposure to both insecticides. C. mexicana also promoted 25 and 21% removal of acephate and imidacloprid, respectively. The biochemical changes in C. mexicana on exposure to acephate and imidacloprid indicate that the microalga undergoes an adaptive change in response to the insecticide-induced oxidative stress.

  2. Production of bio-jet fuel from microalgae

    Science.gov (United States)

    Elmoraghy, Marian

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

  3. Interaction of detritus with abundance of cyanobacteria and microalgae

    NARCIS (Netherlands)

    Gons, H.J.

    1995-01-01

    Detritus particles interact with phytoplankton growth through light attenuation and nutrient retention. A model is described for predicting abundance of cyanobacteria and microalgae in relation to the detritus dynamics in shallow lakes with varying phosphorus load. Steady-state P distribution among

  4. Cultivation of microalgae in a high irradiance area

    NARCIS (Netherlands)

    Cuaresma, M.

    2011-01-01


    Microalgae are a promising source of high-value products (i.e. carotenoids, ω-3 fatty acids), as well as feedstocks for food, bulk chemicals and biofuels. Industrial production is, however, still limited because the technology needs further development. One of the main bottlenecks is th

  5. Analysis and stability of fatty acid esterified xanthophylls from microalgae

    NARCIS (Netherlands)

    Weesepoel, Y.J.A.

    2014-01-01

    Fatty acid esterified xanthophylls (e.g. astaxanthin) produced by microalgae are regarded as a natural alternative for food colourants, but little is known on the stability of these compounds in foods. The aims of this research were (i) to develop protocols to analyze esterified xanthophylls, and th

  6. Vibrating membrane filtration as improved technology for microalgae dewatering.

    Science.gov (United States)

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

    2014-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Maiara Priscilla de Souza

    2013-02-01

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

  8. Horizontal or vertical photobioreactors? How to improve microalgae photosynthetic efficiency

    NARCIS (Netherlands)

    Cuaresma, M.; Janssen, M.G.J.; Vilchez, C.; Wijffels, R.H.

    2011-01-01

    The productivity of a vertical outdoor photobioreactor was quantitatively assessed and compared to a horizontal reactor. Daily light cycles in southern Spain were simulated and applied to grow the microalgae Chlorella sorokiniana in a flat panel photobioreactor. The maximal irradiance around noon di

  9. Separation efficiency of a vacuum gas lift for microalgae harvesting.

    Science.gov (United States)

    Barrut, Bertrand; Blancheton, Jean-Paul; Muller-Feuga, Arnaud; René, François; Narváez, César; Champagne, Jean-Yves; Grasmick, Alain

    2013-01-01

    Low-energy and low-cost separation of microalgae from water is important to the economics of microalgae harvesting and processing. Flotation under vacuum using a vacuum gas lift for microalgae harvesting was investigated for different airflow rates, bubble sizes, salinities and harvest volumes. Harvesting efficiency (HE) and concentration factor (CF) of the vacuum gas lift increased by around 50% when the airflow rate was reduced from 20 to 10 L min(-1). Reduced bubble size multiplied HE and CF 10 times when specific microbubble diffusers were used or when the salinity of the water was increased from 0‰ to 40‰. The reduction in harvest volume from 100 to 1L increased the CF from 10 to 130. An optimized vacuum gas lift could allow partial microalgae harvesting using less than 0.2 kWh kg(-1) DW, thus reducing energy costs 10-100 times compared to complete harvesting processes, albeit at the expense of a less concentrated biomass harvest.

  10. Transcriptional Engineering of Microalgae: Prospects for High-Value Chemicals.

    Science.gov (United States)

    Bajhaiya, Amit K; Ziehe Moreira, Javiera; Pittman, Jon K

    2017-02-01

    Microalgae are diverse microorganisms that are of interest as novel sources of metabolites for various industrial, nutritional, and pharmaceutical applications. Recent studies have demonstrated transcriptional engineering of some metabolic pathways. We propose here that transcriptional engineering could be a viable means to manipulate the biosynthesis of specific high-value metabolic products.

  11. High Lipid Induction in Microalgae for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Peer M. Schenk

    2012-05-01

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

  12. Cell to substratum and cell to cell interactions of microalgae.

    Science.gov (United States)

    Ozkan, Altan; Berberoglu, Halil

    2013-12-01

    This paper reports the cell to substratum and cell to cell interactions of a diverse group of microalgae based on the Extended Derjaguin, Landau, Verwey, Overbeek (XDLVO) approach using the previously reported physico-chemical surface properties. The microalgae included 10 different species of green algae and diatoms from both freshwater and saltwater environments while the substrata included glass, indium-tin oxide (ITO), stainless steel, polycarbonate, polyethylene, and polystryrene. The results indicated that acid-base interactions were the dominating mechanism of interaction for microalgae. For green algae, if at least one of the interacting surfaces was hydrophobic, adhesion at primary minimum was predicted without any energy barrier. However, most diatom systems featured energy barriers for adhesion due to repulsive van der Waals interactions. The results reported in this study are expected to provide useful data and insight into the interaction mechanisms of microalgae cells with each other and with substrata for a number of practical applications including prevention of biofouling of photobioreactors and other man-made surfaces, promotion of biofilm formation in algal biofilm photobioreactors, and developing bioflocculation strategies for energy efficient harvesting of algal biomass. Particularly, Botryococcus braunii and Cerithiopsis fusiformis were identified as promising species for biofloccuation and biofilm formation in freshwater and saltwater aquatic systems, respectively. Finally, based on the observed trends in this study, use of hydrophilic algae and hydrophilic coatings over surfaces are recommended for minimizing biofouling in aquatic systems.

  13. Cultivation of microalgae on artificial light comes at a cost

    NARCIS (Netherlands)

    Blanken, W.M.; Cuaresma Franco, M.; Wijffels, R.H.; Janssen, M.G.J.

    2013-01-01

    Microalgae are potential producers of bulk food and feed compounds, chemicals, and biofuels. To produce these bulk products competitively, it is important to keep costs of raw material low. Light energy can be provided by sun or lamps. Sunlight is free and abundant. Disadvantages of sunlight, howeve

  14. Potential of sponges and microalgae for marine biotechnology

    NARCIS (Netherlands)

    Wijffels, R.H.

    2008-01-01

    Marine organisms can be used to produce several novel products that have applications in new medical technologies, in food and feed ingredients and as biofuels. In this paper two examples are described: the development of marine drugs from sponges and the use of microalgae to produce bulk chemicals

  15. Microalgae harvesting via co-culture with filamentous fungus

    Science.gov (United States)

    Gultom, Sarman Oktovianus

    Microalgae harvesting is a labor- and energy-intensive process. For instance, classical harvesting technologies such as chemical addition and mechanical separation are economically prohibiting for biofuel production. Newer approaches to harvest microalgae have been developed in order to decrease costs. Among these new methods, fungal co-pelletization seems to be a promising technology. By co-culturing filamentous fungi with microalgae, it is possible to form pellets, which can easily be separated. In this study, different parameters for the cultivation of filamentous fungus (Aspergillus niger) and microalgae (Chlorella vulgaris) to efficiently form cell pellets were evaluated under heterotrophic and phototrophic conditions, including organic carbon source (glucose, glycerol and sodium acetate) concentration, pH, initial concentration of fungal spores, initial concentration of microalgal cells, concentration of ionic strength (Calcium and Magnesium) and concentration of salinity (NaCl). In addition, zeta-potential measurements were carried out in order to get a better understanding of the mechanism of attraction. It was found that 2 g/L of glucose, a fungus to microalgae ratio of 1:300, and uncontrolled pH (around 7) are the best culturing conditions for co-pelletization. Under these conditions, it was possible to achieve a high harvesting performance (>90%). In addition, it was observed that most pellets formed in the co-culture were spherical with an average diameter of 3.5 mm and in concentrations of about 5 pellets per mL of culture media. Under phototrophic conditions, co-pelletization required the addition of glucose as organic carbon source to sustain the growth of fungi and to allow the harvesting of microalgae. Zeta-potential measurements indicated that (i) both microalgae and fungi have low zeta-potential values regardless of the pH on the bulk (i.e. <-10 mV) (ii) fungi can have a positive electric charge at low pH (ie. pH=3). These values suggest that it

  16. From transient response of a compact photobioreactor for microalgae cultivation

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  17. Microalgae: the green gold of the future? : large-scale sustainable cultivation of microalgae for the production of bulk commodities

    NARCIS (Netherlands)

    Wolkers, H.; Barbosa, M.J.; Kleinegris, D.M.M.; Bosma, R.; Wijffels, R.H.; Harmsen, P.F.H.

    2011-01-01

    The cultivation of microalgae can play an important role in environmentalfriendly production of raw materials for biodiesel. In addition, algae offer several other useful materials for the food and chemical industry. This booklet describes the possibilities for economically viable large scale algae

  18. Consumo e desempenho de cordeiros e borregos alimentados com dietas de alto concentrado de milho ou sorgo

    Directory of Open Access Journals (Sweden)

    R.S. Venturini

    Full Text Available RESUMO Objetivou-se avaliar os consumos de matéria seca, nutrientes e desempenho na terminação de cordeiros e borregos submetidos a dietas de alto concentrado de grão de milho ou sorgo. Foram utilizados 32 animais, sendo 16 cordeiros (dente de leite e 16 borregos (dois dentes da raça Corriedale. As dietas eram constituídas de feno de aveia- branca (Avena sativa, grão de milho (Zea mays ou de sorgo (Sorghum bicolor (L. Moench, farelo de soja (Glycine Max, calcário calcítico, bicarbonato de sódio e monensina. Os cordeiros apresentaram superioridade (P≤0,05 quanto ao CMS (% do PV e g/kg PV0,75, ao CPB (kg/dia, % do PV e g/kg PV0,75, ao CEE (% do PV, ao CFDN e ao CFDA (% do PV e g/kg PV0,75, ao CNDT (% do PV, ao ganho de peso médio diário, à conformação in vivo e à conversão alimentar. Por outro lado, o CEE, o CCHT e o CCNE (kg/dia, o peso vivo inicial, o peso vivo final e o peso vivo ao abate foram superiores (P≤0,05 na categoria dos borregos. Em relação aos grãos avaliados, verificou-se maior (P≤0,05 CEE (kg/dia, % do PV e g/kg PV0,75 e menor (P≤0,05 CFDN (% do PV e CFDA (kg/dia, % do PV e g/kg PV0,75 para os animais alimentados com dieta de alto concentrado à base de grão de milho em relação àqueles alimentados com grão de sorgo. Os cordeiros apresentam consumos relativos superiores aos borregos, porém sua resposta zootécnica é maior. O uso de dietas de alto concentrado de sorgo ou de milho proporcionou resultados semelhantes.

  19. Control of predators in industrial scale microalgae cultures with Pulsed Electric Fields.

    Science.gov (United States)

    Rego, D; Redondo, L M; Geraldes, V; Costa, L; Navalho, J; Pereira, M T

    2015-06-01

    This work describes the utilization of Pulsed Electric Fields to control the protozoan contamination of a microalgae culture, in an industrial 2.7 m(3) microalgae photobioreactor. The contaminated culture was treated with Pulsed Electric Fields, PEF, for 6h with an average of 900 V/cm, 65 μs pulses of 50 Hz. Working with recirculation, all the culture was uniformly exposed to the PEF throughout the assay. The development of the microalgae and protozoan populations was followed and the results showed that PEF is effective on the selective elimination of protozoa from microalgae cultures, inflicting on the protozoa growth halt, death or cell rupture, without affecting microalgae productivity. Specifically, the results show a reduction of the active protozoan population of 87% after 6h treatment and 100% after few days of normal cultivation regime. At the same time, microalgae growth rate remained unaffected.

  20. Effect of microalgae supplementation on the silage quality and anaerobic digestion performance of Manyflower silvergrass.

    Science.gov (United States)

    Li, Lianhua; Sun, Yongming; Yuan, Zhenhong; Kong, Xiaoying; Wao, Yao; Yang, Ligui; Zhang, Yi; Li, Dong

    2015-01-01

    The silage quality of Manyflower silvergrass with microalgae supplementation was investigated, and the variation in bacterial communities during ensilage period was analyzed by high-throughput sequencing technology. In addition, the specific methane yields of the silages were also evaluated. Results showed that the samples with microalgae supplementation have lower pH value and higher lactic acid concentration (8.0 mg/g FM). Meanwhile, higher NH3-N concentration was observed since microalgae were N-rich material. Microalgae additions also influenced the bacterial community structure. For the samples without microalgae, the major genus was Enterococcus from day 1 to day 3, and then Lactobacillus became the dominant genus. While the prevalent genus represented in the samples with microalgae supplementation was Lactobacillus. The specific methane yields of all samples were within the range of 153 ± 1 mL/g VS to 178 ± 11 mL/g VS and no significant difference was observed.

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

    Science.gov (United States)

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

    2014-10-01

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

  2. Automatic and real time recognition of microalgae by means of pigment signature and shape.

    Science.gov (United States)

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

    2013-07-01

    Microalgae are unicellular photoautotrophic organisms that grow in any habitat such as fresh and salt water bodies, hot springs, ice, air, and in or on other organisms and substrates. Massive growth of microalgae may produce harmful effects on the marine and freshwater ecological environment and fishery resources. Therefore, rapid and accurate recognition and classification of microalgae is one of the most important issues in water resource management. In this paper, a new methodology for automatic and real time identification of microalgae by means of microscopy image analysis is presented. This methodology is based on segmentation, shape features extraction, and characteristic colour (i.e. pigment signature) determination. A classifier algorithm based on the minimum distance criterion was used for microalgae grouping according to the measured features. 96.6% accuracy from a set of 3423 images of 24 different microalgae representing the major algal phyla was achieved by this methodology.

  3. Incorporation of lutein and docosahexaenoic acid from dietary microalgae into the retina in quail.

    Science.gov (United States)

    Schnebelen-Berthier, Coralie; Acar, Niyazi; Pouillart, Philippe; Thabuis, Clementine; Rodriguez, Bertrand; Depeint, Flore; Clerc, Elise; Mathiaud, Adeline; Bourdillon, Anne; Baert, Blandine; Bretillon, Lionel; Lecerf, Jean-Michel

    2015-03-01

    Lutein and docosahexaenoic acid (DHA) are associated with the prevention of age-related macular degeneration (AMD). Since microalgae are potent natural sources of these nutrients, their nutritional value should be evaluated based on the bioavailability of lutein and DHA for the retina via the plasmatic compartment. In this study, quail were fed for 5 months either with a diet supplemented or deprived with microalgae rich in lutein and DHA. In the microalgae-fed group, the retinal concentrations of lutein and zeaxanthin gradually increased whereas in plasma, these compounds started to increase from the first month of supplementation. We also observed a significant increase in retinal and plasmatic levels of DHA in the microalgae-fed group. In conclusion, the plasmatic and retinal contents of lutein and DHA were significantly increased in quail fed with lutein- and DHA-rich microalgae. Food fortification with microalgae may be an innovative way to increase lutein and DHA consumption in humans.

  4. Producción de moina sp alimentada con chlorella spp. cultivada con riles orgánicos de la industria pesquera cubana.

    OpenAIRE

    Romero, Teresita de J.; Manso, B.M.; López,R.; Martínez, F.C.; Moreno, M.

    2010-01-01

    El incremento sustancial de la acuicultura cubana y la carencia de algunos fertilizantes usados para fines de cultivo fitoplantónico, que finalmente pasan a nutrir especies zooplanctónicas como el cladócero Moina, ha dado pauta para realizar el presente estudio, referido al cultivo de dicha especie con la microalga Chlorella spp. desarrollada previamente con riles orgánicos de la industria pesquera. Se realizaron dos tandas experimentales: 1) en acuarios de 50 L de capacidad efect...

  5. 微藻多糖的研究进展%Research progress of microalgae polysaccharide

    Institute of Scientific and Technical Information of China (English)

    李洁琼; 刘红全; 袁莎

    2016-01-01

    The structure of microalgae polysaccharide is analyzed.The purification technologies and main biological activities of microalgae polysaccharide are reviewed.Some suggestions about microalgae polysaccharide are also put forward.%针对微藻多糖的结构组成、分离纯化技术和主要生物活性进行概述,并对其研究进展提出展望.

  6. Effects of Fluctuating Environments on the Selection of High Yielding Microalgae

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-02-27

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

  7. Transgene expression in microalgae – from tools to applications

    Directory of Open Access Journals (Sweden)

    Lior eDoron

    2016-04-01

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

  8. The Growth Condition and Oil Production of Microalgae with Several Kinds of Plant Hormones

    Institute of Scientific and Technical Information of China (English)

    QIU Chen

    2016-01-01

    Microalgae as an important marine resources, rich in high content of polysaccharide, protein, fatty acids. The fatty acid content of microalgae is high, and its propagation speed is faster than herbaceous plants. It also has a high use value. The experiment tried on the basis of the screening of high yield oil microalgae, add different commonly used plant hormone, using growth monitoring, analysis of product components. Select several plant hormones to improve microalgae products production, provides guidance on the deep research and commercial production.

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

    Directory of Open Access Journals (Sweden)

    Krystian Miazek

    2015-10-01

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

  10. A microalgae residue based carbon solid acid catalyst for biodiesel production.

    Science.gov (United States)

    Fu, Xiaobo; Li, Dianhong; Chen, Jie; Zhang, Yuanming; Huang, Weiya; Zhu, Yi; Yang, Jun; Zhang, Chengwu

    2013-10-01

    Biodiesel production from microalgae is recognized as one of the best solutions to deal with the energy crisis issues. However, after the oil extraction from the microalgae, the microalgae residue was generally discarded or burned. Here a novel carbon-based solid acid catalyst derived from microalgae residue by in situ hydrothermal partially carbonization were synthesized. The obtained catalyst was characterized and subjected to both the esterification of oleic acid and transesterification of triglyceride to produce biodiesel. The catalyst showed high catalytic activity and can be regenerated while its activity can be well maintained after five cycles.

  11. Evaluación del crecimiento y supervivencia en larvas de camarón blanco Litopenaeus vannamei usando como fuente de alimento microalgas vivas y congeladas

    Directory of Open Access Journals (Sweden)

    Elifonso Isiordia Pérez:

    2007-05-01

    Full Text Available Resumen matraces de 1.5 litros de capacidad con 5 El objetivo del presente rabajo fue evaluar el eplicas cada tratamiento. La densidad de efecto de una dieta monoalgal a base de dos microalgas a suministrar fue de 50,000 células presentaciones Tetraselmis sp. (vivas y / mililitro. Conforme mudaban de estadio se congeladas:producto comercial: INLAND hacía conteo de organismos vivos y se media Seafarm® en la supervivencia y crecimiento longitud El mayor porcentaje de supervivencia en larvas de camarón blanco Litopenaeus y crecimiento se registró en las larvas vannamei en estadios larvales desde limentadas con Tetraselmis sp. vivas (97.3 Protozoea 1 (PZ1 a Protozoea 3 (PZ3. El ±4.6 en PZI, 94.1 ± 2.13 en PZ2 y 30.7±12.6 experimento se realizó en las instalaciones del en PZ3. Sin embargo este resultado no es Centro de Investigación en Alimentación y comparable a los obtenidos con otras especies Desarrollo (CIAD, Unidad Mazatlán Sinaloa. El de microalgas como Chaetoceros muelleri e estudio se realizó bajo condiciones controladas Isochrysis galbana. de temperatura (28°C, salinidad (35‰ y fotoperiodo (12 h luz / oscuridad. Se sembraron 150 organismos en nauplio V en

  12. Efficient anaerobic digestion of whole microalgae and lipid-extracted microalgae residues for methane energy production.

    Science.gov (United States)

    Zhao, Baisuo; Ma, Jingwei; Zhao, Quanbao; Laurens, Lieve; Jarvis, Eric; Chen, Shulin; Frear, Craig

    2014-06-01

    The primary aim of this study was to completely investigate extensive biological methane potential (BMP) on both whole microalgae and its lipid-extracted biomass residues with various degrees of biomass pretreatment. Specific methane productivities (SMP) under batch conditions for non-lipid extracted biomass were better than lipid-extracted biomass residues and exhibited no signs of ammonia or carbon/nitrogen (C/N) ratio inhibition when digested at high I/S ratio (I/S ratio⩾1.0). SMP for suitably extracted biomass ranged from 0.30 to 0.38LCH4/gVS (volatile solids). For both whole and lipid-extracted biomass, overall organic conversion ranged from 59.33 to 78.50 as a measure of %VS reduction with greater percentage biodegradability in general found within the lipid-extracted biomass. Higher production levels correlated to lipid content with a linear relationship between SMP and ash-free lipid content being developed at a R(2) of 0.814.

  13. Biodiesel production from indigenous microalgae grown in wastewater.

    Science.gov (United States)

    Komolafe, Oladapo; Velasquez Orta, Sharon B; Monje-Ramirez, Ignacio; Yáñez Noguez, Isaura; Harvey, Adam P; Orta Ledesma, María T

    2014-02-01

    This paper describes a process for producing biodiesel sustainably from microalgae grown in wastewater, whilst significantly reducing the wastewater's nutrients and total coliform. Furthermore, ozone-flotation harvesting of the resultant biomass was investigated, shown to be viable, and resulted in FAMEs of greater oxidation stability. Desmodesmus sp. and two mixed cultures were successfully grown on wastewater. Desmodesmus sp. grew rapidly, to a higher maximum biomass concentration of 0.58 g/L. A native mixed culture dominated by Oscillatoria and Arthrospira, reached 0.45 g/L and exhibited the highest lipid and FAME yield. The FAME obtained from ozone-flotation exhibited the greatest oxidative stability, as the degree of saturation was high. In principle ozone could therefore be used as a combined method of harvesting and reducing FAME unsaturation. During microalgae treatment, the total nitrogen in wastewater was reduced by 55.4-83.9%. More importantly, total coliform removal was as high as 99.8%.

  14. Shaking and Blending Effect on Microalgae Concentrates Size

    Directory of Open Access Journals (Sweden)

    LUDI PARWADANI AJI

    2012-03-01

    Full Text Available Microalgae concentrates (paste can be used as an alternative feed to replace live microalgae for aquaculture due to its nutritional value and convenience. However, the clumping of cells and negative buoyancy of algae concentrate can affect bivalve culture as bivalves only capture particles in suspension and ingest a certain size range of particles. This study investigated the effect of shaking and blending treatments on the preparation of food suspensions prepared from algae concentrates (Isochrysis and Pavlova. The results indicated that the higher the shaking time (5, 10, and 15 times or blending time (10, 30, and 60 seconds, the smaller was the diameter of the resulting algae particles. Moreover, the greater the volume of algae concentrate used in preparation, the larger the diameter of algae particles produced. Shaking may be the best option because it is cheaper and simpler. However, all the treatments provided a suitable particle size range for ingestion by bivalves.

  15. Thermal decomposition dynamics and severity of microalgae residues in torrefaction.

    Science.gov (United States)

    Chen, Wei-Hsin; Huang, Ming-Yueh; Chang, Jo-Shu; Chen, Chun-Yen

    2014-10-01

    To figure out the torrefaction characteristics and weight loss dynamics of microalgae residues, the thermogravimetric analyses of two microalgae (Chlamydomonas sp. JSC4 and Chlorella sorokiniana CY1) residues are carried out. A parameter of torrefaction severity index (TSI) in the range of 0-1, in terms of weight loss ratio between a certain operation and a reference operation, is defined to indicate the degree of biomass thermal degradation due to torrefaction. The TSI profiles of the two residues are similar to each other; therefore, the parameter may be used to describe the torrefaction extents of various biomass materials. The curvature of TSI profile along light torrefaction is slight, elucidating its slight impact on biomass thermal degradation. The sharp curvature along severe torrefaction in the initial pretreatment period reveals that biomass upgraded with high temperature and short duration is more effective than using low temperature with long duration.

  16. Food waste as nutrient source in heterotrophic microalgae cultivation.

    Science.gov (United States)

    Pleissner, Daniel; Lam, Wan Chi; Sun, Zheng; Lin, Carol Sze Ki

    2013-06-01

    Glucose, free amino nitrogen (FAN), and phosphate were recovered from food waste by fungal hydrolysis using Aspergillus awamori and Aspergillus oryzae. Using 100g food waste (dry weight), 31.9 g glucose, 0.28 g FAN, and 0.38 g phosphate were recovered after 24h of hydrolysis. The pure hydrolysate has then been used as culture medium and nutrient source for the two heterotrophic microalgae Schizochytrium mangrovei and Chlorella pyrenoidosa, S. mangrovei and C. pyrenoidosa grew well on the complex food waste hydrolysate by utilizing the nutrients recovered. At the end of fermentation 10-20 g biomass were produced rich in carbohydrates, lipids, proteins, and saturated and polyunsaturated fatty acids. Results of this study revealed the potential of food waste hydrolysate as culture medium and nutrient source in microalgae cultivation.

  17. Curvature-guided motility of microalgae in geometric confinement

    CERN Document Server

    Ostapenko, Tanya; Böddeker, Thomas; Kreis, Christian; Cammann, Jan; Mazza, Marco G; Bäumchen, Oliver

    2016-01-01

    Microorganisms often live in microhabitats that consist of a liquid phase and a plethora of typically curved interfaces. The ways in which motile cells possessing propulsive appendages sense and interact with the physical nature of their environment remains unclear today. For pusher-type microswimmers with rear-mounted flagella, such as bacteria and spermatozoa, cell trapping at a wall was attributed to contrasting microscopic mechanisms, namely hydrodynamic and contact interactions. Here, we demonstrate that, in confined spaces, the geometry of the habitat controls the motility of microalgae that propel themselves by the beating of two anterior flagella. Brownian dynamics simulations and analytical theory both quantitatively match the experimental data and capture a characteristic curvature scaling observed in the experiments. This curvature-guided navigation of the microalgae originates from only two essential ingredients: excluded volume resulting in predominantly ballistic swimming in confinement and the ...

  18. Microalgae: a new alternative raw material for biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Gouveia, L.; Rosa, F. [Instituto Nacional de Engenharia, Tecnologia e Inovacao -INETI-DER- Unidade Biomassa. Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); Melo, A. [Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Medeiros, R. [Universidade Lusofona de Humanidades e Tecnologias, Campo Grande, n. 376, Lisboa (Portugal); Oliveira, A. [Extensao da Escola Superior de Biotecnologia em Caldas da Rainha, Universidade Catolica Portuguesa, Rua Mestre Mateus Fernandes, 2500-237 Caldas da Rainha (Portugal)

    2008-07-01

    Biofuels will play an increasingly important role in diversifying energy supplies to meet the world's growing energy needs. Algae are considered a promising potential feedstock for next-generation biofuels because certain species contain high amounts of oil, which could be extracted, processed and refined into transportation fuels using currently available technology. Other benefits of algae as a potential feedstock are their abundance and fast growth rates. Key technical challenges include identifying the strains with the highest oil content and growth rates and developing cost-effective growing and harvesting methods. In this work, a microalgae screening in terms of oil quantity and composition were done in order to choose the best one as oil source for biodiesel production. Oil extraction procedure was optimized and the oil obtained from each microalgae analyzed in terms of fatty acid profile and of some parameters that can influenced the biodiesel production process and the final product quality.

  19. Biodiesel production from microalgae oil catalyzed by a recombinant lipase.

    Science.gov (United States)

    Huang, Jinjin; Xia, Ji; Jiang, Wei; Li, Ying; Li, Jilun

    2015-03-01

    A recombinant Rhizomucor miehei lipase was constructed and expressed in Pichia pastoris. The target enzyme was termed Lipase GH2 and it can be used as a free enzyme for catalytic conversion of microalgae oil mixed with methanol or ethanol for biodiesel production in an n-hexane solvent system. Conversion rates of two major types of biodiesel, fatty acid methyl ester (FAME) and fatty acid ethyl ester (FAEE), reached maximal values (>90%) after 24h. The process of FAME production is generally more simple and economical than that of FAEE production, even though the two processes show similar conversion rates. In spite of the damaging effect of ethanol on enzyme activity, we successfully obtained ethyl ester by the enzymatic method. Our findings indicate that Lipase GH2 is a useful catalyst for conversion of microalgae oil to FAME or FAEE, and this system provides efficiency and reduced costs in biodiesel production.

  20. Improving biogas production from microalgae by enzymatic pretreatment.

    Science.gov (United States)

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

    2016-01-01

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

  1. CO{sub 2} capture and biofuels production with microalgae

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. [Univ. of California, Berkeley, CA (United States)

    1995-11-01

    Microalgae cultivation in large open ponds is the only biological process capable of directly utilizing power plant flue gas CO{sub 2} for production of renewable fuels, such as biodiesel, thus mitigating the potential for global warming. Past and recent systems studies have concluded that in principle this concept could be economically feasible, but that this technology still requires both fundamental and applied long-term R&D.

  2. "Rational" management of dichlorophenols biodegradation by the microalga Scenedesmus obliquus.

    Science.gov (United States)

    Papazi, Aikaterini; Kotzabasis, Kiriakos

    2013-01-01

    The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps) under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp - no meta-substitution) consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp - one meta-chloride) was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp - two meta-chlorides) could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity) was higher, than group I (lower toxicity) and the biodegradation of dichlorophenols (higher toxicity) was higher than the corresponding monochlorophenols (lower toxicity). The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as "smart" bioenergetic "machines", that have the ability to continuously "calculate" the energy reserves and "use" the most energetically

  3. Bacterial bioaugmentation for improving methane and hydrogen production from microalgae

    Science.gov (United States)

    2013-01-01

    Background The recalcitrant cell walls of microalgae may limit their digestibility for bioenergy production. Considering that cellulose contributes to the cell wall recalcitrance of the microalgae Chlorella vulgaris, this study investigated bioaugmentation with a cellulolytic and hydrogenogenic bacterium, Clostridium thermocellum, at different inoculum ratios as a possible method to improve CH4 and H2 production of microalgae. Results Methane production was found to increase by 17?~?24% with the addition of C. thermocellum, as a result of enhanced cell disruption and excess hydrogen production. Furthermore, addition of C. thermocellum enhanced the bacterial diversity and quantities, leading to higher fermentation efficiency. A two-step process of addition of C. thermocellum first and methanogenic sludge subsequently could recover both hydrogen and methane, with a 9.4% increase in bioenergy yield, when compared with the one-step process of simultaneous addition of C. thermocellum and methanogenic sludge. The fluorescence peaks of excitation-emission matrix spectra associated with chlorophyll can serve as biomarkers for algal cell degradation. Conclusions Bioaugmentation with C. thermocellum improved the degradation of C. vulgaris biomass, producing higher levels of methane and hydrogen. The two-step process, with methanogenic inoculum added after the hydrogen production reached saturation, was found to be an energy-efficiency method for hydrogen and methane production. PMID:23815806

  4. Developments and challenges in biodiesel production from microalgae: A review.

    Science.gov (United States)

    Taparia, Tanvi; Mvss, Manjari; Mehrotra, Rajesh; Shukla, Paritosh; Mehrotra, Sandhya

    2016-09-01

    The imminent depletion of fossil fuels and the surging global demand for renewable energy have led to the search for nonconventional energy sources. After a few decades of trial and error, the world is now testing the sources of the third generation of fossil fuels, which contain for most parts microalgae. With more than 80% oil content, being adaptable in growth parameters and highly versatile, microalgae are highly promising sources of biofuels in the present time. The present article makes a sweeping attempt to highlight the various methods employed for cultivation of microalgae, techniques to harvest and extract biomass from huge algal cultures, as well as their downstream production and processing procedures. The advantages, limitations, and challenges faced by each of them have been described to some extent. Major concerns pertaining to biofuels are supposed to be their environmental sustainability and economic viability along with their cost effectiveness. This would require a great deal of empirical data on existing systems and a great deal of optimization to generate a more robust one. We have concluded our article with a SWOT analysis of using algae for biodiesel production in a tabulated form.

  5. Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds

    Science.gov (United States)

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

    2016-01-01

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

  6. Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds.

    Science.gov (United States)

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

    2016-11-22

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

  7. Innovative Alternative Technologies to Extract Carotenoids from Microalgae and Seaweeds

    Directory of Open Access Journals (Sweden)

    Mahesha M. Poojary

    2016-11-01

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

  8. Prospects of biodiesel production from microalgae in India

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-15

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

  9. Maximum hydrogen production from genetically modified microalgae biomass

    Science.gov (United States)

    Vargas, Jose; Kava, Vanessa; Ordonez, Juan

    A transient mathematical model for managing microalgae derived H2 production as a source of renewable energy is developed for a well stirred photobioreactor, PBR. The model allows for the determination of microalgae and H2 mass fractions produced by the PBR in time. A Michaelis-Menten expression is proposed for modeling the rate of H2 production, which introduces an expression to calculate the resulting effect on H2 production rate after genetically modifying the microalgae. The indirect biophotolysis process was used. Therefore, an opportunity was found to optimize the aerobic to anaerobic stages time ratio of the cycle for maximum H2 production rate, i.e., the process rhythm. A system thermodynamic optimization is conducted with the model equations to find accurately the optimal system operating rhythm for maximum H2 production rate, and how wild and genetically modified species compare to each other. The maxima found are sharp, showing up to a ~60% variation in hydrogen production rate within 2 days around the optimal rhythm, which highlights the importance of system operation in such condition. Therefore, the model is expected to be useful for design, control and optimization of H2 production. Brazilian National Council of Scientific and Technological Development, CNPq (project 482336/2012-9).

  10. Direct visualization of microalgae rupture by ultrasound-driven bubbles

    Science.gov (United States)

    Pommella, Angelo; Harun, Irina; Pouliopoulos, Antonis; Choi, James J.; Hellgardt, Klaus; Garbin, Valeria

    2015-11-01

    Cell rupture induced by ultrasound is central to applications in biotechnology. For instance, cell disruption is required in the production of biofuels from microalgae (unicellular species of algae). Ultrasound-induced cavitation, bubble collapse and jetting are exploited to induce sufficiently large viscous stresses to cause rupture of the cell membranes. It has recently been shown that seeding the flow with bubbles that act as cavitation nuclei significantly reduces the energy cost for cell processing. However, a fundamental understanding of the conditions for rupture of microalgae in the complex flow fields generated by ultrasound-driven bubbles is currently lacking. We perform high-speed video microscopy to visualize the miscroscale details of the interaction of Chlamydomonas reinhardtii , microalgae of about 10 μm in size, with ultrasound-driven microbubbles of 2-200 μm in diameter. We investigate the efficiency of cell rupture depending on ultrasound frequency and pressure amplitude (from 10 kPa up to 1 MPa), and the resulting bubble dynamics regimes. In particular we compare the efficiency of membrane rupture in the acoustic microstreaming flow induced by linear oscillations, with the case of violent bubble collapse and jetting. V.G. acknowledges partial support from the European Commission (FP7-PEOPLE-2013-CIG), Grant No. 618333.

  11. Biodiesel renovável derivado de microalgas: avanços e perspectivas tecnológicas

    Directory of Open Access Journals (Sweden)

    Claudio M. P. Pereira

    2012-01-01

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

  12. Rentabilidad de la producción de carne de ovinos Katahdin x Pelibuey con tres tipos de alimentación

    Directory of Open Access Journals (Sweden)

    R. González-Garduño

    2013-01-01

    Full Text Available El objetivo de este trabajo fue determinar la rentabilidad económica de la producción de carne de ovino Katahdin x Pelibuey comparando diferentes tipos de alimentación. Los indicadores se obtuvieron de una unidad de producción con un sistema semi-intensivo tecnificado de estrato socioeconómico medio. Se utilizaron los registros productivos de ovinos en tres experimentos diferentes: a pastoreo con suplementación, b estabulación con una dieta integral de sacchasorgo y c estabulación con alimento comercial. En cada tipo de alimentación se registró el consumo diario individual, y el peso de los corderos cada quince días. Para determinar la rentabilidad se utilizó la Matriz de Análisis de Política (map, donde los ingresos y los costos fueron evaluados a precios de mercado. En la producción de un kilogramo de carne, los insumos comerciables representaron mayor porcentaje en ovinos estabulados (90% respecto de los ovinos en pastoreo (48%. El mayor costo correspondió a la alimentación en todos los casos. En estabulación, los factores internos representaron de 7 a 9% y los costos fijos cerca del 1%; mientras que en ovinos en pastoreo estos indicadores representaron el 38% y 14%, respectivamente. La rentabilidad privada fue de 132% en corderos en pastoreo, 4% en corderos alimentados con sacchasorgo, -11.70% en hembras alimentadas con sacchasorgo y -12.30% en los machos que recibieron alimento comercial. Se concluye que la producción de carne es rentable en corderos en pastoreo y en los machos alimentados con una dieta integral de sacchasorgo, ya que todos los indicadores resultaron positivos.

  13. Simulación de una microgrid de voltaje continuo/alterno alimentado con fuente solar, eólica, baterías y convencional

    OpenAIRE

    Mírez Tarrillo, Jorge Luis

    2011-01-01

    En las últimas décadas, la industria eléctrica está experimentando un cambio fundamental desde el tradicional patrón de operación centralizada hacia la introducción de una gran cantidad de fuentes generadoras conectadas a niveles de distribución de Media Tensión. En los últimos años la tendencia se mueve hacia mallas (Grids) de Baja Tensión entre 200V a 1000V, a través de la interconexiones de pequeñas fuentes modulares de generación eléctrica (microplantas). Esto forma un nuevo tipo de siste...

  14. EVALUACIÓN DEL CRECIMIENTO DE JUVENILES DE PEZ BLANCO (Menidia estor) ALIMENTADOS CON DIETAS A BASE DE PROTEÍNA HIDROLIZADA DE BAGRE ARMADO (Pterygoplichthys disjunctivus).

    OpenAIRE

    AVALOS SÁNCHEZ, ANA MAURICIA

    2012-01-01

    El pez blanco Menidia estor (Jordan 1879) del Lago de Pátzcuaro, Michoacán, es una especie nativa y endémica del altiplano mexicano, perteneciente a la familia Atherinopsidae. Por su valor económico, cultural y nutricional es la especie de mayor importancia en la región, que por muchos años ha sido la base de la subsistencia del pueblo Purépecha. Debido a la intensa explotación y deterioro de su hábitat se le considera como una especie amenazada (Marez y Morales 2003), razón po...

  15. Histologia do fígado de tilápia do Nilo ( Oreochromis niloticus alimentados com dietas contendo silagem biológica de pescado

    Directory of Open Access Journals (Sweden)

    Claucia A. Honorato

    2014-12-01

    Full Text Available Resumo: Este estudo teve como objetivo avaliar as possíveis alterações histopatológicas hepática de tilápias do Nilo alimentadas com dietas contendo silagem biológica de pescado com diferentes concentrações protéicas. Foram utilizados 180 juvenis alimentados com dietas contendo três níveis de proteína (20, 24 and 28% PB, e duas proporções de silagem biológica (¼ e ½ durante 75 dias. Os fragementos de fígado foram fixados em Bouin e inclusos em Histosec®. Posteriorente foram cortados em microtomo com espessura de 2 a 5μm. O método utilizado para coloração foi hematoxilina/eosina e PAS. Os cortes histológicos foram analisados em microscopio de luz. O desarranjo na morfologia do fígado dos peixes alimentados com silagem biológica foi influenciado pelos altos níveis protéicos, e pelo aumento ½ de proporções de proteínas de origem animal das dietas. Foi observado que a variação dos hepatócitos está diretamente ligada com o tipo da dieta fornecida para os peixes. Nos peixes alimentados com as dietas contendo 28% PB, o fígado apresentou desarranjo da estrutura cordonal dos hepatócitos, pontos de necrose e deslocamento do núcleo para periferia. Níveis elevados de silagem biológica de pescado provoca alterações deletérias no fígado. O nível de proteína adequado para manter o desenvolvimento associado à saúde do peixe é de 24%PB.

  16. Mild disintegration of the green microalgae Chlorella vulgaris using bead milling

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    NARCIS (Netherlands)

    Jonker, J.G.G.; Faaij, A.P.C.

    2013-01-01

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

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

    Science.gov (United States)

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

    2016-03-01

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

  19. Sorting cells of the microalga Chlorococcum littorale with increased triacylglycerol productivity

    NARCIS (Netherlands)

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

    2016-01-01

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

  20. Short-term antioxidative responses of 15 microalgae exposed to excessive irradiance including ultraviolet radiation

    NARCIS (Netherlands)

    Janknegt, Paul J.; De Graaff, C. Marco; Van De Poll, Willem H.; Visser, Ronald J. W.; Rijstenbil, Jan W.; Buma, Anita G. J.

    2009-01-01

    Short-term photosensitivity and oxidative stress responses were compared for three groups of marine microalgae: Antarctic microalgae, temperate diatoms and temperate flagellates. In total, 15 low-light-acclimated species were exposed to simulated surface irradiance including ultraviolet radiation (S

  1. Milking of microalgae: Production and selective extraction of Beta-carotene in two-phase bioreactors

    NARCIS (Netherlands)

    Hejazi, M.

    2003-01-01

    The low productivity of photobioreactors used for production of high-value compounds from microalgae is a big bottleneck in commercialization. "Milking" of microalgae for the production of high-value compounds in which the produced biomass is reused for production can be a solutio

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  3. Cultivation of microalgae: effect of light/dark cycles on biomass yield

    NARCIS (Netherlands)

    Janssen, M.G.J.

    2002-01-01

    In this thesis the efficiency of light utilization of microalgae was studied under light/dark cycles encountered in photobioreactors. Phototrophic microorganisms such as microalgae and cyanobacteria could provide valuable compounds. For many of these applications it is essential to use enclosed phot

  4. Use of methylene blue uptake for assessing cell viability of colony-forming microalgae

    NARCIS (Netherlands)

    Lemos Bicas, J.; Kleinegris, D.M.M.; Barbosa, M.J.

    2015-01-01

    During the past few years, interest in microalgae has grown, mainly because of their potential for biofuel production. Botryococcus braunii, a green microalga that can accumulate more than half of its dry weight as hydrocarbons, is one of the most important examples. This microorganism grows in colo

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

    NARCIS (Netherlands)

    Reijnders, L.

    2013-01-01

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

  6. Hepatopatía crónica e insuficiencia hepática en un lactante con malformación de la placa ductal

    OpenAIRE

    Flora Zárate-Mondragón; Eduardo López-Corella

    2016-01-01

    Paciente masculino de 5 meses, producto de la segunda gesta de una madre de 33 años, sana, con control prenatal, ingesta de ácido fólico y multivitamínicos. Fue obtenido por cesárea por falta de progresión del trabajo de parto, a término, con peso de 3 800 g, talla 52 cm, Apgar 8-9, lloró y respiró al nacer. Egresó al segundo día como “binomio” sano. Onfalorrexis a los 20 días. Sin antecedentes herodofamiliares de importancia para el padecimiento actual. Alimentado con leche materna exclusiva...

  7. Comportamento ingestivo de cordeiros em confinamento, alimentados com dieta exclusiva de concentrado com diferentes porcentagens de proteína

    Directory of Open Access Journals (Sweden)

    L.G.A. Cirne

    2014-02-01

    Full Text Available O experimento foi realizado com o objetivo de avaliar o comportamento ingestivo de cordeiros em confinamento, alimentados com dieta exclusiva de concentrado com diferentes porcentagens de proteína (14, 16, 18 e 20%. Foram utilizados 24 cordeiros mestiços da raça Santa Inês, não castrados, com aproximadamente 180 dias de idade, peso vivo médio de 25kg, confinados, num delineamento experimental inteiramente ao acaso, com quatro tratamentos e seis repetições. O tempo despendido na atividade de alimentação decresceu linearmente em 0,20 hora/dia para cada 1% de aumento na porcentagem de proteína na dieta; o de ócio aumentou linearmente em 0,25 hora/dia; e o de mastigação total reduziu linearmente em 0,25 hora/dia. A elevação da porcentagem de proteína na dieta elevou linearmente a eficiência de alimentação (kg MS e FDN/hora, em 0,038 e 0,005kg/hora, respectivamente, para as frações MS e FDN. Contudo, os consumos de matéria seca (MS e fibra em detergente neutro (FDN, a eficiência de ruminação (kg MS e FDN/hora, assim como o período (nº/dia e o tempo (min gasto por período de alimentação, ruminação e ócio não foram influenciados pelas diferentes porcentagens de proteína na dieta.

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

    Science.gov (United States)

    Costa, Jorge Alberto Vieira; de Morais, Michele Greque

    2011-01-01

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

  9. Marine microalgae growth and carbon partitioning as a function of nutrient availability.

    Science.gov (United States)

    Fernandes, Tomásia; Fernandes, Igor; Andrade, Carlos A P; Cordeiro, Nereida

    2016-08-01

    To understand in which way the structural differences of three marine microalgae (Nannochloropsis gaditana, Rhodomonas marina and Isochrysis sp.) affect their carbon partitioning, growth and applicability; a stoichiometric imbalance was imposed by steady carbon and other nutrients variation. Towards high nutrients concentrations/low carbon availability a decrease of 12-51% in C/N microalgae ratio was observed and maximum cell densities were achieved. Moreover, linear correlation between the nutrient input and microalgae protein content were observed. The macromolecular ratios pointed that carbohydrate was the main contributor for the C/N decrement. Although lipid content in R. marina remained constant throughout the experiment, a rise of 37-107% in N. gaditana and Isochrysis sp. was verified. Lipid fractions revealed high percentages of glycolipids in all microalgae (57-73% of total lipids). The present study shows an easy way to understand and modulate microalgae carbon partitioning relying on the field of application.

  10. Potential yields and properties of oil from the hydrothermal liquefaction of microalgae with different biochemical content.

    Science.gov (United States)

    Biller, P; Ross, A B

    2011-01-01

    A range of model biochemical components, microalgae and cyanobacteria with different biochemical contents have been liquefied under hydrothermal conditions at 350 °C, ∼200 bar in water, 1M Na(2)CO(3) and 1M formic acid. The model compounds include albumin and a soya protein, starch and glucose, the triglyceride from sunflower oil and two amino acids. Microalgae include Chlorella vulgaris,Nannochloropsis occulata and Porphyridium cruentum and the cyanobacteria Spirulina. The yields and product distribution obtained for each model compound have been used to predict the behaviour of microalgae with different biochemical composition and have been validated using microalgae and cyanobacteria. Broad agreement is reached between predictive yields and actual yields for the microalgae based on their biochemical composition. The yields of bio-crude are 5-25 wt.% higher than the lipid content of the algae depending upon biochemical composition. The yields of bio-crude follow the trend lipids>proteins>carbohydrates.

  11. Flocculation properties of several microalgae and a cyanobacterium species during ferric chloride, chitosan and alkaline flocculation.

    Science.gov (United States)

    Lama, Sanjaya; Muylaert, Koenraad; Karki, Tika Bahadur; Foubert, Imogen; Henderson, Rita K; Vandamme, Dries

    2016-11-01

    Flocculation holds great potential as a low-cost harvesting method for microalgae biomass production. Three flocculation methods (ferric chloride, chitosan, and alkaline flocculation) were compared in this study for the harvesting of 9 different freshwater and marine microalgae and one cyanobacterium species. Ferric chloride resulted in a separation efficiency greater than 90% with a concentration factor (CF) higher than 10 for all species. Chitosan flocculation worked generally very well for freshwater microalgae, but not for marine species. Alkaline flocculation was most efficient for harvesting of Nannochloropsis, Chlamydomonas and Chlorella sp. The concentration factor was highly variable between microalgae species. Generally, minimum flocculant dosages were highly variable across species, which shows that flocculation may be a good harvesting method for some species but not for others. This study shows that microalgae and cyanobacteria species should not be selected solely based on their productivity but also on their potential for low-cost separation.

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

    Directory of Open Access Journals (Sweden)

    Xuan Luo

    2015-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Krystian Miazek

    2014-07-01

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

  14. Perspectives on the feasibility of using microalgae for industrial wastewater treatment.

    Science.gov (United States)

    Wang, Yue; Ho, Shih-Hsin; Cheng, Chieh-Lun; Guo, Wan-Qian; Nagarajan, Dillirani; Ren, Nan-Qi; Lee, Duu-Jong; Chang, Jo-Shu

    2016-12-01

    Although microalgae can serve as an appropriate alternative feedstock for biofuel production, the high microalgal cultivation cost has been a major obstacle for commercializing such attempts. One of the feasible solution for cost reduction is to couple microalgal biofuel production system with wastewater treatment, as microalgae are known to effectively eliminate a variety of nutrients/pollutants in wastewater, such as nitrogen/phosphate, organic carbons, VFAs, pharmaceutical compounds, textile dye compounds, and heavy metals. This review aims to critically discuss the feasibility of microalgae-based wastewater treatment, including the strategies for strain selection, the effect of wastewater types, photobioreactor design, economic feasibility assessment, and other key issues that influence the treatment performance. The potential of microalgae-bacteria consortium for treatment of industrial wastewaters is also discussed. This review provides useful information for developing an integrated wastewater treatment with microalgal biomass and biofuel production facilities and establishing efficient co-cultivation for microalgae and bacteria in such systems.

  15. Development of microalgae biomaterials with enhanced antioxidant activity using electron beam

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  16. Microalgae conversion to biogas: thermal pretreatment contribution on net energy production.

    Science.gov (United States)

    Passos, Fabiana; Ferrer, Ivet

    2014-06-17

    Microalgal biomass harvested from wastewater treatment high rate algal ponds may be valorised through anaerobic digestion producing biogas. However, microalgae anaerobic biodegradability is limited by their complex cell wall structure. Thus, pretreatment techniques are being investigated to improve microalgae methane yield. In the current study, thermal pretreatment at relatively low temperatures of 75-95 °C was effective at enhancing microalgae anaerobic biodegradability; increasing the methane yield by 70% in respect to nonpretreated biomass. Microscopic images showed how the pretreatment damaged microalgae cells, enhancing subsequent anaerobic digestion. Indeed, digestate images showed how after pretreatment only species with resistant cell walls, such as diatoms, continued to be present. Energy balances based on lab-scale reactors performance at 20 days HRT, shifted from neutral to positive (energy gain around 2.7 GJ/d) after thermal pretreatment. In contrast with electricity consuming pretreatment methods, such as microwave irradiation, thermal pretreatment of microalgae seems to be scalable.

  17. Intensification of microalgae drying and oil extraction process by vapor recompression and heat integration.

    Science.gov (United States)

    Song, Chunfeng; Liu, Qingling; Ji, Na; Deng, Shuai; Zhao, Jun; Kitamura, Yutaka

    2016-05-01

    Reducing energy penalty caused by drying and oil extraction is the most critical challenge in microalgae biodiesel production. In this study, vapor recompression and heat integration are utilized to optimize the performance of wet microalgae drying and oil extraction. In the microalgae drying stage, the hot exhaust stream is recompressed and coupled with wet microalgae to recover the condensate heat. In the oil extraction stage, the exergy rate of recovered solvent is also elevated by compressor and then exchanged heat with feed and bottom stream in the distillation column. Energy and mass balance of the intensified process is investigated and compared with the conventional microalgae drying-extraction process. The simulation results indicated that the total energy consumption of the intensified process can be saved by 52.4% of the conventional route.

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

    Science.gov (United States)

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

    2014-12-01

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

  19. PRODUCCIÓN DE BIODIESEL A PARTIR DE MICROALGAS: PARÁMETROS DEL CULTIVO QUE AFECTAN LA PRODUCCIÓN DE LÍPIDOS

    Directory of Open Access Journals (Sweden)

    MARTHA TRINIDAD ARIAS PEÑARANDA

    2013-01-01

    Full Text Available Las microalgas poseen la capacidad para mitigar las emisiones de CO2 y producir lípidos, por lo que se consideran con potencial para la obtención de biocombustibles de tercera generación. La presente revisión proporciona información actualizada de la influencia de las condiciones de cultivo, sobre la obtención de lípidos con una produc- tividad elevada y perfil adecuado para la producción de biodiesel, se proporciona una síntesis de resultados de investigaciones realizadas en los últimos 13 años en diversas partes del mundo. En la literatura consultada, los autores concluyen que aunque el comportamiento de las microalgas ante condiciones de estrés fisiológico es variable entre especies; la limitación de nutrientes especialmente nitrógeno y fósforo, asociado al crecimiento heterotrófico o a altas intensidades luminosas en fototrofía se consideran como las estrategias más eficientes para incrementar el contenido de lípidos en las microalgas, en particular de triglicéridos constituidos por ácidos grasos saturados y monoinsaturados, ideales para la producción de biodiesel. De igual forma, señalan que la presencia de pequeñas cantidades de CO2 y la cosecha de la biomasa en la fase es- tacionaria de crecimiento, incrementan el contenido de lípidos y disminuyen el número de insaturaciones de los ácidos grasos que lo conforman.

  20. Producción de Moina sp alimentada con Chlorella spp. cultivada con riles orgánicos de la industria pesquera cubana - Production of Moina sp fed with Chlorella spp. developed in organic waste waters from Cuban fishing industry

    Directory of Open Access Journals (Sweden)

    Romero Teresita de J

    2010-12-01

    Full Text Available ResumenEl incremento importante de la acuicultura cubana y la carencia de algunos fertilizantes usados para fines de cultivo fitoplantónico, que finalmente pasan a nutrir especies zooplanctónicas como el cladócero Moina sp, ha motivado el presente estudio, referido al cultivo de dicha especie con la microalga Chlorella spp. desarrollada previamente con riles orgánicos de la industria pesquera.SummarySubstantial increase of Cuban acuiculture and deficiency of some fertilizers used for the phytoplanktonic cultures, that finally feed the zooplanktonic species like cladocera Moina, provides the possibility of conducting the current study, referred to the culture of this species with microalga Chlorella spp. previously developed in waste waters of the fishing industry.

  1. Larvicultura de Rhamdia quelen (Pisces, Pimelodidae con proteína vegetal y animal, suplementadas con plancton

    Directory of Open Access Journals (Sweden)

    Germán Castañeda A.

    2011-12-01

    Full Text Available Objetivo. Determinar el efecto de dietas con diferentes proporciones de fuentes proteicas animales y vegetales suplementadas con plancton sobre el crecimiento y sobrevivencia en larvas de Rhamdia quelen. Materiales y métodos. Fueron formuladas dos dietas experimentales, dieta-1 con 70% de proteína de origen vegetal (torta de soya y dieta-2 con 70% de proteína proveniente de animales (corazón bovino yharina de pescado; se utilizaron cuatro protocolos de alimentación (cinco réplicas por tratamiento: dieta-1 + plancton filtrado en tamiz de 50-200 micras (T1, dieta-2 + plancton filtrado en tamiz de 50-200 micras (T2, dieta-1 (T3, dieta-2 (T4. Las larvas fueron manejadas a una densidad de 20 animales L-1 suministrando alimentohasta aparente saciedad diariamente a las 07:00, 11:00, 16:00 y 21:00 horas; la suplementación con plancton se realizó a las 11:00 y 21:00 horas. Resultados. Entre T1 y T2 no se observaron diferencias estadísticas (p>0.05 en peso final (21.89 ± 15.17mg vs 20.37 ± 10.37mg, longitud total (13.41±2.34mm vs 13.39±1.99 mm, factor de condición (K (0.80±0.13 vs 0.78±0.13 y sobrevivencia (46.6±2.68% vs36.0±7.41%; las diferencias entre T3 y T4 tampoco fueron significativas (3.35±1.40 mg vs 2.98±1.48 mg; 7.54±0.91mm vs 7.33±0.96mm; 0.75±0.13 vs 0.71±0.12; 33.6±9.07% vs 24.8±6.76%, respectivamente; hubo diferencias significativas (p<0.05 entre los grupos suplementados con plancton y los alimentados solo con ración. Conclusiones. La suplementación con plancton fue más efectiva que elofrecimiento solo de ración. La inclusión del 62.9% de torta de soya en la formulación (T1, aparentemente no afectó el crecimiento ni la sobrevivencia.

  2. An ultrasonically enhanced inclined settler for microalgae harvesting.

    Science.gov (United States)

    Hincapié Gómez, Esteban; Marchese, Anthony J

    2015-01-01

    Microalgae have vast potential as a sustainable and scalable source of biofuels and bioproducts. However, algae dewatering is a critical challenge that must be addressed. Ultrasonic settling has already been exploited for concentrating various biological cells at relatively small batch volumes and/or low throughput. Typically, these designs are operated in batch or semicontinuous mode, wherein the flow is interrupted and the cells are subsequently harvested. These batch techniques are not well suited for scaleup to the throughput levels required for harvesting microalgae from the large-scale cultivation operations necessary for a viable algal biofuel industry. This article introduces a novel device for the acoustic harvesting of microalgae. The design is based on the coupling of the acoustophoretic force, acoustic transparent materials, and inclined settling. A filtration efficiency of 70 ± 5% and a concentration factor of 11.6 ± 2.2 were achieved at a flow rate of 25 mL·min(-1) and an energy consumption of 3.6 ± 0.9 kWh·m(-3) . The effects of the applied power, flow rate, inlet cell concentration, and inclination were explored. It was found that the filtration efficiency of the device is proportional to the power applied. However, the filtration efficiency experienced a plateau at 100 W L(-1) of power density applied. The filtration efficiency also increased with increasing inlet cell concentration and was inversely proportional to the flow rate. It was also found that the optimum settling angle for maximum concentration factor occurred at an angle of 50 ± 5°. At these optimum conditions, the device had higher filtration efficiency in comparison to other similar devices reported in the previous literature.

  3. Longitudinal Analysis of Microbiota in Microalga Nannochloropsis salina Cultures.

    Science.gov (United States)

    Geng, Haifeng; Sale, Kenneth L; Tran-Gyamfi, Mary Bao; Lane, Todd W; Yu, Eizadora T

    2016-07-01

    Large-scale open microalgae cultivation has tremendous potential to make a significant contribution to replacing petroleum-based fuels with biofuels. Open algal cultures are unavoidably inhabited with a diversity of microbes that live on, influence, and shape the fate of these ecosystems. However, there is little understanding of the resilience and stability of the microbial communities in engineered semicontinuous algal systems. To evaluate the dynamics and resilience of the microbial communities in microalgae biofuel cultures, we conducted a longitudinal study on open systems to compare the temporal profiles of the microbiota from two multigenerational algal cohorts, which include one seeded with the microbiota from an in-house culture and the other exogenously seeded with a natural-occurring consortia of bacterial species harvested from the Pacific Ocean. From these month-long, semicontinuous open microalga Nannochloropsis salina cultures, we sequenced a time-series of 46 samples, yielding 8804 operational taxonomic units derived from 9,160,076 high-quality partial 16S rRNA sequences. We provide quantitative evidence that clearly illustrates the development of microbial community is associated with microbiota ancestry. In addition, N. salina growth phases were linked with distinct changes in microbial phylotypes. Alteromonadeles dominated the community in the N. salina exponential phase whereas Alphaproteobacteria and Flavobacteriia were more prevalent in the stationary phase. We also demonstrate that the N. salina-associated microbial community in open cultures is diverse, resilient, and dynamic in response to environmental perturbations. This knowledge has general implications for developing and testing design principles of cultivated algal systems.

  4. Adaptation of microalgae to a gradient of continuous petroleum contamination

    Energy Technology Data Exchange (ETDEWEB)

    Carrera-Martinez, Daniel; Mateos-Sanz, Aranzazu [AlgasGen Biotecnologia, EBT-UCM, Facultad de Veterinaria, Universidad Complutense de Madrid, Puerta de Hierro s/n, E-28040 Madrid (Spain); Lopez-Rodas, Victoria [AlgasGen Biotecnologia, EBT-UCM, Facultad de Veterinaria, Universidad Complutense de Madrid, Puerta de Hierro s/n, E-28040 Madrid (Spain); Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, Puerta de Hierro s/n, E-28040 Madrid (Spain); Costas, Eduardo, E-mail: ecostas@vet.ucm.es [AlgasGen Biotecnologia, EBT-UCM, Facultad de Veterinaria, Universidad Complutense de Madrid, Puerta de Hierro s/n, E-28040 Madrid (Spain); Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, Puerta de Hierro s/n, E-28040 Madrid (Spain)

    2011-01-25

    In order to study adaptation of microalgae to petroleum contamination, we have examined an environmental stress gradient by crude oil contamination in the Arroyo Minero River (AMR), Argentina. Underground crude oil has constantly leaked out since 1915 as a consequence of test drilling for possible petroleum exploitation. Numerous microalgae species proliferated in AMR upstream of the crude oil spill. In contrast, only four microalgal species were detected in the crude oil spill area. Species richness increases again downstream. Microalgae biomass in the crude oil spill area is dominated by a mesophile species, Scenedesmus sp. Effects of oil samples from AMR spill on photosynthetic performance and growth were studied using laboratory cultures of two Scenedesmus sp. strains. One strain (Se-co) was isolated from the crude oil spill area. The other strain (Se-pr) was isolated from a pristine area without petroleum contamination. Crude oil has undetectable effects on Se-co strain. In contrast crude oil rapidly destroys Se-pr strain. However, Se-pr strain can adapt to low doses of petroleum ({<=}3% v/v total hydrocarbons/water) by means of physiological acclimatization. In contrast, only rare crude oil-resistant mutants are able to grow under high levels of crude oil ({>=}10% v/v total hydrocarbons/water). These crude oil-resistant mutants have arisen through rare spontaneous mutations that occur prior to crude oil exposure. Species richness in different areas of AMR is closely connected to the kind of mechanism (genetic adaptation vs. physiological acclimatization) that allows adaptation. Resistant-mutants are enough to assure the survival of microalgal species under catastrophic crude oil spill.

  5. Carbon dioxide fixation by microalgae cultivated in open bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Centeno da Rosa, Ana Priscila; Fernandes Carvalho, Lisiane; Goldbeck, Luzia [Laboratory of Biochemical Engineering, College of Chemistry and Food, Federal University of Rio Grande (FURG), P.O. Box 474, Rio Grande, RS 96201-900 (Brazil); Vieira Costa, Jorge Alberto, E-mail: dqmjorge@furg.br [Laboratory of Biochemical Engineering, College of Chemistry and Food, Federal University of Rio Grande (FURG), P.O. Box 474, Rio Grande, RS 96201-900 (Brazil)

    2011-08-15

    Highlights: {yields} We studied the growth and CO{sub 2} fixation by Spirulina LEB18 and Chlorella kessleri. {yields} The maximum dailyfixation was obtained for Spirulina with an injection of 6% of CO{sub 2}. {yields} The microalgae presented growth during the 20 d of culture with up to 18% of CO{sub 2}. {yields} The use of CO{sub 2} from industrial generation decreases the cost of producing biomass. - Abstract: The biofixation of carbon dioxide (CO{sub 2}) by microalgae has been proven to be an efficient and economical method, mainly due to the photosynthetic ability of these microorganisms to use this gas as a source of nutrients for their development. The aim of this work was to study the growth of Spirulina LEB18 and Chlorella kessleri microalgae, exposed to controlled and non-controlled conditions, with the injection of different concentrations of CO{sub 2}. The cultures was carried out in 6 L open raceway ponds, under controlled conditions at 30 {sup o}C and 39 {mu}E m{sup -2} s{sup -1} and under non-controlled conditions, protected by a tunnel of transparent film. The experiments were subjected to CO{sub 2} injections at concentrations of 0.038, 6, 12 and 18% (v/v). The highest concentration of biomass (4.95 g L{sup -1}) and maximum daily fixation (0.21 g g{sup -1} d{sup -1}) were obtained for Spirulina LEB18 in culture that was prepared in non-controlled conditions with an injection of 6% (v/v) of CO{sub 2}. C. kessleri had maximum (p < 0.0008) specific growth rate (0.84 d{sup -1}) when grown with 18% (v/v) of CO{sub 2} in non-controlled conditions of cultivation.

  6. DNA Barcoding Green Microalgae Isolated from Neotropical Inland Waters.

    Directory of Open Access Journals (Sweden)

    Sámed I I A Hadi

    Full Text Available This study evaluated the feasibility of using the Ribulose Bisphosphate Carboxylase Large subunit gene (rbcL and the Internal Transcribed Spacers 1 and 2 of the nuclear rDNA (nuITS1 and nuITS2 markers for identifying a very diverse, albeit poorly known group, of green microalgae from neotropical inland waters. Fifty-one freshwater green microalgae strains isolated from Brazil, the largest biodiversity reservoir in the neotropics, were submitted to DNA barcoding. Currently available universal primers for ITS1-5.8S-ITS2 region amplification were sufficient to successfully amplify and sequence 47 (92% of the samples. On the other hand, new sets of primers had to be designed for rbcL, which allowed 96% of the samples to be sequenced. Thirty-five percent of the strains could be unambiguously identified to the species level based either on nuITS1 or nuITS2 sequences' using barcode gap calculations. nuITS2 Compensatory Base Change (CBC and ITS1-5.8S-ITS2 region phylogenetic analysis, together with morphological inspection, confirmed the identification accuracy. In contrast, only 6% of the strains could be assigned to the correct species based solely on rbcL sequences. In conclusion, the data presented here indicates that either nuITS1 or nuITS2 are useful markers for DNA barcoding of freshwater green microalgae, with advantage for nuITS2 due to the larger availability of analytical tools and reference barcodes deposited at databases for this marker.

  7. Fuel options from microalgae with representative chemical compositions

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, D. A.

    1984-07-01

    Representative species of microalgae are examined with respect to their reported chemical compositions. Each species is analyzed under a variety of culture conditions, with the objective being to characterize an optimum mixture of fuel products (e.g., methane, ethanol, methylester) which should be produced by the particular species. Historically the emphasis has been on the entire algal cell mass. Using the reported chemical composition for the representative species under specific sets of growth conditions, some conclusions can be drawn about the preferred fuel product conversion routes that could be employed. 10 references, 7 figures, 12 tables.

  8. Potential of microalgae and cyanobacteria in bioremediation of distillery wastewaters

    OpenAIRE

    Isis Amores-Sanchez; María del Carmen Terrón-Orellana; Aldo E. González-Becerra; Tania González-Díaz de Villegas

    2015-01-01

    Los efluentes de destilerías, también llamados vinazas, son unos de los residuales más agresivos para el medio ambiente. Muchos estudios han focalizado los biotratamientos al uso de hongos y bacterias, pero la descontaminación eficiente de dicho efluente es todavía un problema sin resolver. En los últimos tiempos microalgas y cianobacterias han surgido como una alternativa muy promisoria a la destoxificación. Estos microorganismo ofrecen una serie de ventajas como son: la degradación de gran ...

  9. Recent developments on biofuels production from microalgae and macroalgae

    DEFF Research Database (Denmark)

    Kumar, Kanhaiya; Ghosh, Supratim; Angelidaki, Irini

    2016-01-01

    energetically and commercially viable. Macroalgae are low in lipid content. Therefore, the use of macroalgae is restricted for gaseous fuels or fermentative methods of liquid biofuels production. Anaerobic digestion of algal biomass is easy and seems promising as the process is simple in terms of engineering...... and infrastructure requirement. Hydrogen production by microalgae through biophotolysis seems interesting as it directly converts the solar energy into hydrogen. However, the process has not been scaled-up till today. Hydrothermal liquefaction (HTL) is more promising due to handling of wet biomass at moderate...... temperature and pressure and conversion of whole biomass into high quality oil. However, HTL process is energy intensive....

  10. Towards a luxury uptake process via microalgae--defining the polyphosphate dynamics.

    Science.gov (United States)

    Powell, Nicola; Shilton, Andy; Chisti, Yusuf; Pratt, Steven

    2009-09-01

    Microalgae in waste stabilization ponds (WSP) have been shown to accumulate polyphosphate. This luxury uptake of phosphorus is influenced by the wastewater phosphate concentration, light intensity and temperature, but the dynamics of how these factors affect luxury uptake with respect to time are not understood. With improved understanding of the dynamics of this mechanism and how it could be manipulated, a phosphorus removal process utilizing luxury uptake by microalgae might be developed. In this work, luxury uptake was investigated by chemical extraction of the acid-soluble and acid-insoluble fractions of polyphosphate in the microalgae. The results showed that the initial accumulation and subsequent utilization of both acid-soluble polyphosphate (ASP) and acid-insoluble polyphosphate (AISP) is a function of the wastewater phosphate concentration. It was found that light intensity influenced both the accumulation and utilization of ASP. The temperature influenced the accumulation of AISP. AISP is believed to be a form of phosphorus storage and ASP is involved in metabolism however, the results of this work show that ASP can also act as a short term form of phosphorus storage. To optimize luxury uptake by microalgae a 'luxury uptake pond' is proposed where the conditions the microalgae are exposed to can be manipulated. This 'luxury uptake pond' would be designed to expose the microalgae to a high phosphate concentration and high light intensity for a short period of time in order to achieve optimal polyphosphate accumulation. Subsequent harvesting would then remove the phosphorus rich microalgae from the system.

  11. Photosynthetic aeration in biological wastewater treatment using immobilized microalgae-bacteria symbiosis.

    Science.gov (United States)

    Praveen, Prashant; Loh, Kai-Chee

    2015-12-01

    Chlorella vulgaris encapsulated in alginate beads were added into a bioreactor treating synthetic wastewater using Pseudomonas putida. A symbiotic CO2/O2 gas exchange was established between the two microorganisms for photosynthetic aeration of wastewater. During batch operation, glucose removal efficiency in the bioreactor improved from 50% in 12 h without aeration to 100% in 6 h, when the bioreactor was aerated photosynthetically. During continuous operation, the bioreactor was operated at a low hydraulic retention time of 3.3 h at feed concentrations of 250 and 500 mg/L glucose. The removal efficiency at 500 mg/L increased from 73% without aeration to 100% in the presence of immobilized microalgae. The initial microalgae concentration was critical to achieve adequate aeration, and the removal rate increased with increasing microalgae concentration. The highest removal rate of 142 mg/L-h glucose was achieved at an initial microalgae concentration of 190 mg/L. Quantification of microalgae growth in the alginate beads indicated an exponential growth during symbiosis, indicating that the bioreactor performance was limited by oxygen production rates. Under symbiotic conditions, the chlorophyll content of the immobilized microalgae increased by more than 30%. These results indicate that immobilized microalgae in symbiosis with heterotrophic bacteria are promising in wastewater aeration.

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

    Science.gov (United States)

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

    2014-07-01

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

  13. Microalgae population dynamics in photobioreactors with secondary sewage effluent as culture medium

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    Adriano E. Marchello

    2015-03-01

    Full Text Available Nitrogen and phosphorus present in sewage can be used for microalgae growth, possibiliting cost reduction in the production of microalgae at the same time that it decreases the eutrophication potential of the effluent. This research aimed at monitoring the native community of microalgae and coliform bacteria in a secondary effluent from anaerobic municipal sewage treatment. Two treatments (aerated and non-aerated were performed to grow microalgae under semi-controlled conditions in semi-closed photobioreactors in a greenhouse. The results showed no significant pH and coliforms (total and Escherichia coli variation between treatments. Nutrient concentrations were reduced supporting microalgae growth up to 107 cells.mL−1independent of aeration. Exponential growth was obtained from the first day for the non-aerated, but a 5 day lag phase of growth was obtained for the aerated. Chlorella vulgaris was the dominant microalgae (99.9% in both treatments. In the aerated, 5 algae classes were detected (Chlorophyceae, Cyanophyceae, Chrysophyceae, Bacillariophyceae and Euglenophyceae, with 12 taxa, whereas in the non-aerated, 2 classes were identified (Chlorophyceae and Cyanophyceae, with 5 taxa. We concluded that effluent is viable for microalgae growth, especially Chlorella vulgaris, at the same time that the eutrophication potential and coliforms are decreased, contributing for better quality of the final effluent.

  14. Microalgae population dynamics in photobioreactors with secondary sewage effluent as culture medium.

    Science.gov (United States)

    Marchello, Adriano E; Lombardi, Ana T; Dellamano-Oliveira, Maria José; de Souza, Clovis W O

    2015-03-01

    Nitrogen and phosphorus present in sewage can be used for microalgae growth, possibiliting cost reduction in the production of microalgae at the same time that it decreases the eutrophication potential of the effluent. This research aimed at monitoring the native community of microalgae and coliform bacteria in a secondary effluent from anaerobic municipal sewage treatment. Two treatments (aerated and non-aerated) were performed to grow microalgae under semi-controlled conditions in semi-closed photobioreactors in a greenhouse. The results showed no significant pH and coliforms (total and Escherichia coli ) variation between treatments. Nutrient concentrations were reduced supporting microalgae growth up to 10 (7) cells.mL (-1) independent of aeration. Exponential growth was obtained from the first day for the non-aerated, but a 5 day lag phase of growth was obtained for the aerated. Chlorella vulgaris was the dominant microalgae (99.9%) in both treatments. In the aerated, 5 algae classes were detected (Chlorophyceae, Cyanophyceae, Chrysophyceae, Bacillariophyceae and Euglenophyceae), with 12 taxa, whereas in the non-aerated, 2 classes were identified (Chlorophyceae and Cyanophyceae), with 5 taxa. We concluded that effluent is viable for microalgae growth, especially Chlorella vulgaris, at the same time that the eutrophication potential and coliforms are decreased, contributing for better quality of the final effluent.

  15. HISTOLOGIA DO INTESTINO DE TILÁPIA DO NILO ALIMENTADOS COM DIETAS CONTENDO DIFERENTES FONTES DE PROTEÍNA

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    Claudinei da Cruz

    2013-06-01

    Full Text Available This work was carried out evaluate the action of the fermented fish silage and fish meal in the middle O. niloticus intestine histochimical. The great epithelium intestinal was in the fishes fed with fish silage independent the animal origin protein proportions in diets. It was observed that the variation of the goblet cells secretion glicoproteic intensity is linked directly to the diet supplied to animals. The middle intestine of O. niloticusshowed differences in the neutral mucus glicoproteic, acid glicoproteic and glicoconjugated secretion pattern, depending on the protein origin and the percentage used in the diet, demonstrating that this species can adapt its secretion system for the protection of the digesting apparatus during the absorption of different protein sources.O objetivo deste trabalho foi avaliar a histologia e a histoquímica do intestino anterior de tilápia do Nilo alimentadas com dietas contendo farinha de peixe ou silagem de peixe como fonte de proteína de origem animal. A espessura da vilosidade intestinal dos peixes alimentados com silagem fermentada de resíduo de tilápia foi influenciada pelos teores protéicos, independente das proporções de proteína de origem animal das dietas. Observouse que a variação da intensidade de secreção de glicoproteínas pelas células caliciformes está diretamente ligada com o tipo de dieta fornecida aos animais. O intestino médio de O. niloticus apresentou diferenças no padrão de secreção de muco glicoproteíco neutro, glicoproteínas ácidas e glicoconjugados, dependendo da origem da proteína e da porcentagem utilizada na dieta, demonstrando que esta espécie pode adaptar seu sistema de secreção para a proteção do aparelho digestório durante a absorção diferentes fontes protéicas.

  16. INDUCCIÓN DE LA PRODUCCIÓN DE LÍPIDOS TOTALES EN MICROALGAS SOMETIDAS A ESTRÉS NUTRITIVO

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    Marianela COBOS RUIZ

    2016-01-01

    Full Text Available Se evaluó la producción de lípidos totales en cinco especies de microalgas inducidas por la ausencia de nitrógeno. Las microalgas empleadas fueron Ankistrodesmus sp., Ankistrodesmus nannoselene, Chlorella sp., Scenedesmus sp. y Scenedesmus quadricauda. Estas especies fueron cultivadas en medio CHU10 con y sin nitrógeno. El tiempo de evaluación fue de seis días, determinándose diariamente la densidad microalgal mediante recuento en cámara de Neubahuer. Se determinó la tasa de crecimiento, la biomasa microalgal y el porcentaje de lípidos totales. Los lípidos totales fueron extraídos con solución Cloroformo:metanol (2:1. Los resultados indicaron que las especies con mayor producción de lípidos totales fueron Ankistrodesmus sp. (263,6 mg/g biomasa seca, A. nannoselene (316 mg/g biomasa seca y Scenedesmus sp. (243,3 mg/g biomasa seca al ser cultivadas en medios sin nitrógeno. Scenedesmus quadricauda y Chlorella sp., fueron las especies que mostraron mayor producción de biomasa seca (159,1 mg/g biomasa seca y 221,1 mg/g biomasa seca respectivamente en medios con nitrógeno. La tasa de crecimiento fue variable entre las especies cultivadas en ambas condiciones. En conclusión, Ankistrodesmus sp., mostró la mayor tasa de crecimiento (0,77 dia-1 en medio sin nitrógeno. Bajo las mismas condiciones de cultivo, Scenedesmus sp. obtuvo la mayor producción de biomasa en peso seco (174,7 mg/l y Ankistrodesmus nannoselene acumuló el mayor porcentaje de lípidos totales.

  17. Cryopreservation of the microalgae Chaetoceros calcitrans (Paulsen: analysis of the effect of DMSO temperature and light regime during different equilibrium periods Criopreservación de las microalgas Chaetoceros calcitrans (Paulsen: análisis del efecto de la temperatura de DMSO y régimen de luz durante diferentes períodos de equilibrio

    Directory of Open Access Journals (Sweden)

    Joan Sebastián Salas-Leiva

    2011-07-01

    Full Text Available We evaluated the effect of three variables (cryoprotectant temperature, light regime, and time of exposure to the cryoprotectant throughout the equilibrium period during cryopreservation on the viability of the microalga Chaetoceros calcitrans (Paulsen. For this, the cryoprotectant dimethyl sulfoxide (DMSO at 5% (v/v was added at three different temperatures (4, 10, and 25°C before placing the microalgae in cryobiological straws for freezing. Once inside the cryobiological straws, the microalgal-cryoprotectant suspensions were subjected to the following light regimes for 15 or 45 min: complete light, complete darkness, light/darkness, and darkness/light. Suspensions were then frozen under controlled conditions and stored in liquid nitrogen. The viability index proposed by Cañavate & Lubian (1995b was used to measure microalgal viability after cryopreservation. Results indicated that it is necessary to use a cryoprotectant to ensure the viable cryopreservation of C. calcitrans. Statistical analyses showed that the temperature of the DMSO influenced the viability of cryopreserved microalgae and that there was no synergistic effect between the other variables studied. The viabilities obtained with DMSO at 25°C, 10°C, and 4°C were 34.9%, 27.8%, and 20.6%, respectively.Se evaluó el efecto de tres variables - la temperatura del crioprotector, el régimen de luz y el tiempo de exposición al crioprotector durante el período de equilibrio en el proceso de criopreservación -sobre la viabilidad de la microalga Chaetoceros calcitrans (Paulsen. Para ello se utilizó, el crioprotector dimetilsulfóxido (DMSO al 5% (v/v, el cual fue adicionado a tres temperaturas diferentes (4, 10 y 25°C antes de que las microalgas fueran introducidas dentro de pajuelas criobiológicas para su congelación. Una vez dentro de las pajuelas, las suspensiones de microalgas con crioprotector se sometieron durante 15 o 45 min a luz completa, oscuridad completa, luz

  18. TAXAS DE FILTRAÇÃO E INGESTÃO DE UMA MICROALGA POR Philodina roseola (Rotifera: Bdelloidea

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    Raquel Aparecida MOREIRA

    2016-01-01

    Full Text Available Los rotíferos desempeñan un importante papel en los ciclos biogeoquímicos y en la productividad orgánica de los ecosistemas de agua dulce como consecuencia de sus elevadas tasas metabólicas. Es relevante la información sobre la filtración, su principal proceso de adquisición de energía, la cual es todavía escasa para la región tropical. Los rotíferos de la subclase Bdelloidea se alimentan por filtración o raspaje, consumiendo pequeños elementos alimentícios, como bacterias, algas, levaduras o materia orgánica particulada. Sabemos poco del papel que desempeñan en la dinámica trófica de los hábitats que ocupan, y por eso el objetivo de este estudio fue cuantificar en laboratorio las tasas de filtración e ingestión del rotífero Philodina roseola , alimentado con Raphidocelis subcapitata . El experimento consistió en la exposición de diez adultos por tratamiento en concentraciones entre 1x10 4 y 1x10 7 células mL -1 y bajo temperatura de 25±1 °C. Los experimentos tuvieron la duración de una hora y las concentraciones iniciales y finales de la suspensión algal fueron cuantificadas por conteo numérico de las células en cámara de Neubauer. No fueron encontradas diferencias significativas entre las concentraciones iniciales y finales de células en los controles, lo cual indica que no se presentó crecimiento algal. Las tasas de filtración de P. roseola variaron entre 0,09 y 0,25 mL ind -1 h -1 . Teniendo en cuenta que la filtración es el principal proceso de adquisición de energía de la Philodina roseola , así como de los demás rotíferos, y que comprende cuestiones importantes relacionadas con la dinámica trófica de los ecosistemas acuáticos, es importante ampliar la información con experimentos usando otros tipos de alimento y diferentes combinaciones de las condiciones experimentales.

  19. Optimization of process configuration and strain selection for microalgae-based biodiesel production.

    Science.gov (United States)

    Yu, Nan; Dieu, Linus Tao Jie; Harvey, Simon; Lee, Dong-Yup

    2015-10-01

    A mathematical model was developed for the design of microalgae-based biodiesel production system by systematically integrating all the production stages and strain properties. Through the hypothetical case study, the model suggested the most economical system configuration for the selected microalgae strains from the available processes at each stage, thus resulting in the cheapest biodiesel production cost, S$2.66/kg, which is still higher than the current diesel price (S$1.05/kg). Interestingly, the microalgae strain properties, such as lipid content, effective diameter and productivity, were found to be one of the major factors that significantly affect the production cost as well as system configuration.

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

    Science.gov (United States)

    Yu, Wei-Luen; Ansari, William; Schoepp, Nathan G; Hannon, Michael J; Mayfield, Stephen P; Burkart, Michael D

    2011-11-02

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

  1. Evaluation of available saline water resources in New Mexico for the production of microalgae

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, R.; Hernandez, J.; Enis, P.; Truby, D.; Mapel, C.

    1990-08-01

    Researchers evaluated saline water resources in New Mexico for their suitability as sites for large-scale microalgae production facilities. Production of microalgae could provide a renewable source of fuel, chemicals, and food. In addition, making use of the unused saline water resources would increase the economic activity in the state. After analyzing the 15 billion acre-ft of unused saline water resources in the state, scientists narrowed the locations down to six sites with the most potential. With further analysis, they chose the Tularosa Basin in southern New Mexico as the best-suited area for 100-hectare microalgae production facility. 34 refs., 38 figs., 14 tabs.

  2. Hypocholesterolemic Effects of Nutraceuticals Produced from the Red Microalga Porphyridium sp. in Rats

    Directory of Open Access Journals (Sweden)

    Shoshana Malis Arad

    2009-11-01

    Full Text Available Red microalgae contain functional sulfated polysaccharides (containing dietary fibers, polyunsaturated fatty acids, zeaxanthin, vitamins, minerals, and proteins. Studies in rat models support the therapeutic properties of algal biomass and isolated polysaccharides. Algal products incorporated into rat diets were found to significantly improve total serum cholesterol, serum triglycerides, hepatic cholesterol levels, HDL/LDL ratios and increased fecal excretion of neutral sterols and bile acids. Morphological and metabolic changes were induced by consumption of algal products. These results suggest that red microalgae can be used as potent hypocholesterolemic agents, and they support the potential use of red microalgae as novel nutraceuticals.

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

    Directory of Open Access Journals (Sweden)

    Bruna da Silva Vaz

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Alexey Llopiz

    2016-05-01

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

  5. Removal of nitrate and phosphate from aqueous solutions by microalgae

    Directory of Open Access Journals (Sweden)

    M.H. Sayadi

    2016-12-01

    Full Text Available The aim of this study was to evaluate the ability of microalgae Spirulina platensis and Chlorella vulgaris to remove nitrate and phosphate in aqueous solutions. Spirulina platensis and Chlorella vulgar is microalgae was collected in 1000 ml of municipal water and KNO3, K2HPO4 was added as sources of nitrate and phosphate in three different concentrations (0.25, 0.35 and 0.45g/L. During the growth period, the concentration of nitrate and phosphate was recorded at 1, 4, 6 and 8 days. The highest nitrate removal on the 8 day for Chlorella vulgaris was 89.80% at the treatment of 0.25g/L and for Spirulina platensis was 81.49% at the treatment of 0.25g/L. The highest phosphate removal for Spirulina platensis was 81.49% at the treatment of 0.45g/L and for Chlorella vulgaris was 88% at the treatment of 0.45g/L. The statistical results showed that the amount of phosphate and nitrate removal during different time periods by Chlorella vulgaris depicted a significant difference at P

  6. The feasibility of biodiesel production by microalgae using industrial wastewater.

    Science.gov (United States)

    Wu, Li Fen; Chen, Pei Chung; Huang, Ai Ping; Lee, Chi Mei

    2012-06-01

    This study investigated nitrogen and phosphorus assimilation and lipid production of microalgae in industrial wastewater. Two native strains of freshwater microalgae were evaluated their biomass growth and lipid production in modified BBM medium. Chlamydomonas sp. TAI-2 had better biomass growth and higher lipid production than Desmodesmus sp.TAI-1. The optimal growth and lipid accumulation of Chlamydomonas sp. TAI-2 were tested under different nitrogen sources, nitrogen and CO(2) concentrations and illumination period in modified BBM medium. The optimal CO(2) aeration was 5% for Chlamydomonas sp. TAI-2 to achieve maximal lipid accumulation under continuous illumination. Using industrial wastewater as the medium, Chlamydomonas sp. TAI-2 could remove 100% NH(4)(+)-N (38.4 mg/L) and NO(3)(-)-N (3.1mg/L) and 33% PO(4)(3-)-P (44.7 mg/L) and accumulate the lipid up to 18.4%. Over 90% of total fatty acids were 14:0, 16:0, 16:1, 18:1, and 18:3 fatty acids, which could be utilized for biodiesel production.

  7. Ultrastructural and flow cytometric analyses of lipid accumulation in microalgae

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, J.A.; Hand, R.E. Jr.; Mann, R.C.

    1986-12-01

    Lipid accumulation in three species of microalgae was investigated with flow cytometry (FCM) and transmission electron microscopy (TEM). Previous studies using batch cultures of a algae have led to the assumption that lipid accumulation in microalgae is a gradual process requiring at least several days for completion. However, FCM reveals, through changes in the chlorophyll:lipid ratio, that the time span required for individual cells to change metabolic state is short. Simultaneous FCM measurements of chlorophyll and nile red (neutral lipid) fluorescence in individual cells of nitrogen-deficient Isochrysis populations revealed a bimodal population distribution as one stage in the lipid accumulation process. The fact that two discrete populations exist, with few cells in an intermediate stage, suggests rapid response to a liqid trigger. Interpretations of light and electron microscopic observations are consistent with this hypothesis. The time required for an entire population to achieve maximum lipid content is considerably longer than that required for a single cell, due to the variation in response time among cells. In this study high lipid cultures were sometimes obtained by using FCM to separate high lipid cells from the remainder of the population. FCM holds much promise for strain enhancement but considerable developmental work, directed at providing more consistent results, remains to be done. 8 refs., 35 figs.

  8. Extraction of hydrocarbons from microalga Botryococcus braunii with switchable solvents.

    Science.gov (United States)

    Samorì, Chiara; Torri, Cristian; Samorì, Giulia; Fabbri, Daniele; Galletti, Paola; Guerrini, Franca; Pistocchi, Rossella; Tagliavini, Emilio

    2010-05-01

    Lipid extraction is a critical step in the development of biofuels from microalgae. Here a new procedure was proposed to extract hydrocarbons from dried and water-suspended samples of the microalga Botryococcus braunii by using switchable-polarity solvents (SPS) based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and an alcohol. The high affinity of the non-ionic form of DBU/alcohol SPS towards non-polar compounds was exploited to extract hydrocarbons from algae, while the ionic character of the DBU-alkyl carbonate form, obtained by the addition of CO(2), was used to recover hydrocarbons from the SPS. DBU/octanol and DBU/ethanol SPS were tested for the extraction efficiency of lipids from freeze-dried B. braunii samples and compared with n-hexane and chloroform/methanol. The DBU/octanol system was further evaluated for the extraction of hydrocarbons directly from algal culture samples. DBU/octanol exhibited the highest yields of extracted hydrocarbons from both freeze-dried and liquid algal samples (16% and 8.2% respectively against 7.8% and 5.6% with n-hexane).

  9. Cyanobacteria and microalgae: a positive prospect for biofuels.

    Science.gov (United States)

    Parmar, Asha; Singh, Niraj Kumar; Pandey, Ashok; Gnansounou, Edgard; Madamwar, Datta

    2011-11-01

    Biofuel-bioenergy production has generated intensive interest due to increased concern regarding limited petroleum-based fuel supplies and their contribution to atmospheric CO2 levels. Biofuel research is not just a matter of finding the right type of biomass and converting it to fuel, but it must also be economically sustainable on large-scale. Several aspects of cyanobacteria and microalgae such as oxygenic photosynthesis, high per-acre productivity, non-food based feedstock, growth on non-productive and non-arable land, utilization of wide variety of water sources (fresh, brackish, seawater and wastewater) and production of valuable co-products along with biofuels have combined to capture the interest of researchers and entrepreneurs. Currently, worldwide biofuels mainly in focus include biohydrogen, bioethanol, biodiesel and biogas. This review focuses on cultivation and harvesting of cyanobacteria and microalgae, possible biofuels and co-products, challenges for cyanobacterial and microalgal biofuels and the approaches of genetic engineering and modifications to increase biofuel production.

  10. Improving microalgae for biotechnology--From genetics to synthetic biology.

    Science.gov (United States)

    Hlavova, Monika; Turoczy, Zoltan; Bisova, Katerina

    2015-11-01

    Microalgae have traditionally been used in many biotechnological applications, where each new application required a different species or strain expressing the required properties; the challenge therefore is to isolate or develop, characterize and optimize species or strains that can express more than one specific property. In agriculture, breeding of natural variants has been successfully used for centuries to improve production traits in many existing plant and animal species. With the discovery of the concepts of classical genetics, these new ideas have been extensively used in selective breeding. However, many biotechnologically relevant algae do not possess the sexual characteristics required for traditional breeding/crossing, although they can be modified by chemical and physical mutagens. The resulting mutants are not considered as genetically modified organisms (GMOs) and their cultivation is therefore not limited by legislation. On the other hand, mutants prepared by random or specific insertion of foreign DNA are considered to be GMOs. This review will compare the effects of two genetic approaches on model algal species and will summarize their advantages in basic research. Furthermore, we will discuss the potential of mutagenesis to improve microalgae as a biotechnological resource, to accelerate the process from specific strain isolation to growth optimization, and discuss the production of new products. Finally, we will explore the potential of algae in synthetic biology.

  11. Heavy Metal Bioaccumulation and Toxicity with Special Reference to Microalgae

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key component of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active transport or by endocytosis through chelating proteins and affect various physiological and biochemical processes of the algae. The toxicity primarily results from their binding to the sulphydryl groups in proteins or disrupting protein structure or displacing essential elements. Metals can break the oxidative balance of the algae, inducing antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX). The amount of oxidized proteins and lipids in the algal cells thus indicates the severity of the stress. Algal tolerance to heavy metal is highly dependent upon the defense response against the probable oxidative damages. Production of binding factors and proteins, exclusion of metals from cells by ion-selective transporters and excretion or compartmentalization have been suggested with regard to reducing heavy metal toxicity. However, a comprehensive description on the mechanisms underlining metal toxicity of microalgae and gaining tolerance is yet to be elaborated.

  12. Challenges and opportunities for hydrogen production from microalgae.

    Science.gov (United States)

    Oey, Melanie; Sawyer, Anne Linda; Ross, Ian Lawrence; Hankamer, Ben

    2016-07-01

    The global population is predicted to increase from ~7.3 billion to over 9 billion people by 2050. Together with rising economic growth, this is forecast to result in a 50% increase in fuel demand, which will have to be met while reducing carbon dioxide (CO2 ) emissions by 50-80% to maintain social, political, energy and climate security. This tension between rising fuel demand and the requirement for rapid global decarbonization highlights the need to fast-track the coordinated development and deployment of efficient cost-effective renewable technologies for the production of CO2 neutral energy. Currently, only 20% of global energy is provided as electricity, while 80% is provided as fuel. Hydrogen (H2 ) is the most advanced CO2 -free fuel and provides a 'common' energy currency as it can be produced via a range of renewable technologies, including photovoltaic (PV), wind, wave and biological systems such as microalgae, to power the next generation of H2 fuel cells. Microalgae production systems for carbon-based fuel (oil and ethanol) are now at the demonstration scale. This review focuses on evaluating the potential of microalgal technologies for the commercial production of solar-driven H2 from water. It summarizes key global technology drivers, the potential and theoretical limits of microalgal H2 production systems, emerging strategies to engineer next-generation systems and how these fit into an evolving H2 economy.

  13. Thermochemical liquefaction characteristics of microalgae in sub- and supercritical ethanol

    Energy Technology Data Exchange (ETDEWEB)

    You, Qiao; Chen, Liang [College of Environmental Science and Engineering, Hunan University, Changsha (China); Key Laboratory of Environment Biology and Pollution Control, Ministry of Education, Changsha (China)

    2011-01-15

    Thermochemical liquefaction characteristics of Spirulina, a kind of high-protein microalgae, were investigated with the sub- and supercritical ethanol as solvent in a 1000 mL autoclave. The influences of various liquefaction parameters on the yields of products (bio-oil and residue) from the liquefaction of Spirulina were studied, such as the reaction temperature (T), the S/L ratio (R{sub 1}, solid: Spirulina, liquid: ethanol), the solvent filling ratio (R{sub 2}) and the type and dosage of catalyst. Without catalyst, the bio-oil yields were in the range of 35.4 wt.% and 45.3 wt.% depending on the changes of T, R{sub 1} and R{sub 2}. And the bio-oil yields increased generally with increasing T and R{sub 2}, while the bio-oil yields reduced with increasing R{sub 1}. The FeS catalyst was certified to be an ideal catalyst for the liquefaction of Spirulina microalgae for its advantages on promoting bio-oil production and suppressing the formation of residue. The optimal dosage of catalyst (FeS) was ranging from 5-7 wt.%. The elemental analyses and FT-IR and GC-MS measurements for the bio-oils revealed that the liquid products have much higher heating values than the crude Spirulina sample and fatty acid ethyl ester compounds were dominant in the bio-oils, irrespective of whether catalyst was used. (author)

  14. Conversion of microalgae to jet fuel: process design and simulation.

    Science.gov (United States)

    Wang, Hui-Yuan; Bluck, David; Van Wie, Bernard J

    2014-09-01

    Microalgae's aquatic, non-edible, highly genetically modifiable nature and fast growth rate are considered ideal for biomass conversion to liquid fuels providing promise for future shortages in fossil fuels and for reducing greenhouse gas and pollutant emissions from combustion. We demonstrate adaptability of PRO/II software by simulating a microalgae photo-bio-reactor and thermolysis with fixed conversion isothermal reactors adding a heat exchanger for thermolysis. We model a cooling tower and gas floatation with zero-duty flash drums adding solids removal for floatation. Properties data are from PRO/II's thermodynamic data manager. Hydrotreating is analyzed within PRO/II's case study option, made subject to Jet B fuel constraints, and we determine an optimal 6.8% bioleum bypass ratio, 230°C hydrotreater temperature, and 20:1 bottoms to overhead distillation ratio. Process economic feasibility occurs if cheap CO2, H2O and nutrient resources are available, along with solar energy and energy from byproduct combustion, and hydrotreater H2 from product reforming.

  15. Anaerobic Co-Digestion of the Microalgae Scenedesmus Sp.

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Suarez, J. L.; Carreras, N.

    2011-06-07

    Microalgae biomass has been widely studied for biogas production over the last years and results show that anaerobic digestion is often limited by the low C/N ratio of this type of biomass. Therefore, codigestion with substrates of high C/N ratio is necessary. The objectives of this study are to set up an experimental method that ease reproducibility and control of anaerobic digestion processes in laboratory conditions and to determine the biodegradability and biogas production potential of the co-digestion process of microalgae Scenedesmus sp. and energy crop Opuntia ficus indica (L.) Miller. Results obtained showed that higher C/N ratios are preferred in order to maximize methane production. Highest methane yield obtained was 0.252m3CH4/Kg VS and degradability expressed as percentage COD reduced is around 30% for the ideal mixture found, made up of 75% O. ficus-indica and 25% Scenedesmus sp. in VS basis. A laboratory setup using MicroOxymax respirometer, after its adaptation to work under anaerobic conditions, can be used for the monitoring of anaerobic digestion processes. Scenedesmus sp. as sole substrate for anaerobic digestion does not give good results due to low C/N ratio. However, when codigesting it with O. ficus-indica methane production is satisfactory. Best mixture was made up of 75% O. ficus-indica and 25% Scenedesmus sp. in VS basis. (Author)

  16. Fundamentals in Microalgae Harvesting: From Flocculation to Self-attachment

    Science.gov (United States)

    Cui, Yan

    Microalgae are a very promising source of biodiesel and other renewable energy due to their fast grow rates, high lipid contents and tremendous potential for water conservation and CO2 biofixation. However, a bottleneck issue with algae biofuel manufacturing is the lack of cost-effective harvesting methods. This research focuses on the technologies for improved microalgae harvesting to enable commercially viable and environmentally friendly biodiesel production. The first objective of this study was to optimize flocculation of marine microalga Nannochloropsis oculata with metal salts, aluminum sulfate (A.S.) and ferric chloride (F.C.) via response surface methodology. It was found that there existed a positive stoichiometric relationship between the flocculant dose (FD) and the initial biomass concentration (IABC). Optimum flocculation conditions were predicted at IABC of 1.7 g/l, pH 8.3, and FD of 383.5 microM for A.S., and IABC of 2.2 g/l, pH 7.9, and FD of 438.1 microM for F.C., under which the predicted maximum harvested solid concentration of algae were 32.98 and 30.10 g/l by using A.S. and F.C., respectively. The second objective was to investigate the mechanism of microalgae flocculation with metal salts. The theory of Derjaguin, Landau, Verwey and Overbeek (DLVO) was applied to understand the flocculation mechanism of a freshwater alga Scenedesmus dimorphus and a marine alga Nannochloropsis oculata under various pH and aluminum sulphate ionic strengths. Effective flocculation was achieved as a result of charge neutralization and sweep flocculation. When low flocculant dosage (microalgae offered possibilities in design of a novel semi-immobilized algal production and harvesting method, which exploited cell to substrata interactions instead of cell-to-cell interactions. In such method, a solid carrier was used to grow and accumulate algal cells and the cost of harvesting and drying can be simply reduced by easy algae-water separation. In order to enable the

  17. Arteterapia con personas con discapacidad intelectual

    OpenAIRE

    Lorenzo Pipkau, Milena

    2015-01-01

    Este proyecto pretende hacer una aproximaci??n al mundo del Arte Terapia y los beneficios que esta disciplina puede aportar a las personas con discapacidad intelectual. La idea surge de la experiencia previa de la autora en este ??mbito y con este colectivo. A trav??s de la documentaci??n bibliogr??fica se busca ampliar el conocimiento en cuanto al concepto de arteterapia y sus antecedentes, con la finalidad de elaborar una propuesta pr??ctica que se basar?? en el dise??o de un taller de arte...

  18. INDUCCIÓN DE LA PRODUCCIÓN DE LÍPIDOS TOTALES EN MICROALGAS SOMETIDAS A ESTRÉS NUTRITIVO

    Directory of Open Access Journals (Sweden)

    Marianela Cobos Ruiz

    2015-11-01

    Full Text Available RESUMENSe evaluó la producción de lípidos totales en cinco especies de microalgas inducidas por la ausencia de nitrógeno. Las microalgas empleadas fueron Ankistrodesmus sp., Ankistrodesmus nannoselene, Chlorella sp., Scenedesmus sp. y Scenedesmus quadricauda. Estas especies fueron cultivadas en medio CHU10 con y sin nitrógeno. El tiempo de evaluación fue de seis días, determinándose diariamente la densidad microalgal mediante recuento en cámara de Neubahuer. Se determinó la tasa de crecimiento, la biomasa microalgal y el porcentaje de lípidos totales. Los lípidos totales fueron extraídos con solución Cloroformo:metanol (2:1. Los resultados indicaron que las especies con mayor producción de lípidos totales fueron Ankistrodesmus sp. (263,6 mg/g biomasa seca, A. nannoselene (316 mg/g biomasa seca y Scenedesmus sp. (243,3 mg/g biomasa seca al ser cultivadas en medios sin nitrógeno. Scenedesmus quadricauda y Chlorella sp., fueron las especies que mostraron mayor producción de biomasa seca (159,1 mg/g biomasa seca y 221,1 mg/g biomasa seca respectivamente en medios con nitrógeno. La tasa de crecimiento fue variable entre las especies cultivadas en ambas condiciones. En conclusión, Ankistrodesmus sp., mostró la mayor tasa de crecimiento (0,77 dia-1 en medio sin nitrógeno. Bajo las mismas condiciones de cultivo, Scenedesmus sp. obtuvo la mayor producción de biomasa en peso seco (174,7 mg/l y Ankistrodesmus nannoselene acumuló el mayor porcentaje de lípidos totales.ABSTRACTThe production of total lipids in five microalgal species was induced by absence of nitrogen. The microalgae Ankistrodesmus sp., Ankistrodesmus nannoselene, Chlorella sp., Scenedesmus sp. and Scenedesmus quadricauda were cultured in CHU10 medium with and without nitrogen. They were evaluated during six days. The microalgae density was daily determined by a Neubahuer chamber. The average growth, total biomass and total lipids were also determined. The total

  19. Desempenho produtivo e econômica de surubins (Pseudoplatystoma sp. alimentados com níveis de proteína e estocados em tanque-rede

    Directory of Open Access Journals (Sweden)

    C. A. Honorato

    2015-10-01

    Full Text Available RESUMOO surubim (Pseudoplatystoma sp. é uma das espécie de peixe mais apreciadas para o consumo. Por ser uma espécie carnívora, exige atenção especial no que tange às suas exigências nutricionais. Até o momento, poucos estudos foram realizados para estabelecê-las na fase de engorda, em especial em sistema de cultivo intensivo. O objetivo do presente estudo foi avaliar os desempenhos zootécnico e econômico de surubins (Pseudoplatystoma sp. na fase final de crescimento, estocados em tanque-rede e alimentados com dietas com diferentes níveis de proteína. Os peixes, com peso de 356,6±40,3g, foram acondicionados em 12 tanques-rede de 18m3, nos quais permaneceram por cinco meses até adquirirem o peso comercial para abate. O tratamento experimental foi constituído por três dietas extrusadas comerciais, com os níveis de proteína bruta (36, 38, 40%PB sendo substituídos gradativamente por carboidratos. Foram avaliados os parâmetros de crescimento, rendimento de filé, enzimas metabólicas e desempenho econômico. O ganho de peso, o ganho de peso diário, o consumo de dieta, a taxa de eficiência proteica, a sobrevivência e o rendimento de filé não apresentaram diferença significativa. A conversão alimentar foi melhor para os peixes alimentados com a dieta com 38 e 40%PB. Não foram observadas diferenças significativas para os parâmetros de índice hepatossomático e de enzimas hepáticas. Apesar dos maiores gastos com a ração contendo 38%PB em comparação à dieta com 36%PB, esta foi a que apresentou o melhor índice de custo por kg de peixe produzido. Os melhores índices de crescimento e o menor custo de arraçoamento foram obtidos pelos peixes alimentados com a dieta 38%PB, sendo esta, portanto recomendada para o arraçoamento na fase final de surubins em tanque-rede.

  20. Chitosan and Its Derivatives Applied in Harvesting Microalgae for Biodiesel Production: An Outlook

    Directory of Open Access Journals (Sweden)

    Guanyi Chen

    2014-01-01

    Full Text Available Although oil-accumulating microalgae are a promising feedstock for biodiesel production, large-scale biodiesel production is not yet economically feasible. As harvesting accounts for an important part of total production cost, mass production of microalgae biodiesel requires an efficient low-energy harvesting strategy so as to make biodiesel production economically attractive. Chitosan has emerged as a favorable flocculating agent in harvesting of microalgae. The aim of this paper is to review current research on the application of chitosan and chitosan-derived materials for harvesting microalgae. This offers a starting point for future studies able to invalidate, confirm, or complete the actual findings and to improve knowledge in this field.

  1. Cultivation and energy efficient harvesting of microalgae using thermoreversible sol-gel transition

    Science.gov (United States)

    Estime, Bendy; Ren, Dacheng; Sureshkumar, Radhakrishna

    2017-01-01

    Microalgae represent a promising source of renewable biomass for the production of biofuels and valuable chemicals. However, energy efficient cultivation and harvesting technologies are necessary to improve economic viability. A Tris-Acetate-Phosphate-Pluronic (TAPP) medium that undergoes a thermoreversible sol-gel transition is developed to efficiently culture and harvest microalgae without affecting the productivity as compared to that in traditional culture in a well-mixed suspension. After seeding microalgae in the TAPP medium in a solution phase at 15 °C, the temperature is increased by 7 °C to induce gelation. Within the gel, microalgae are observed to grow in large clusters rather than as isolated cells. The settling velocity of the microalgal clusters is approximately ten times larger than that of individual cells cultured in typical solution media. Such clusters are easily harvested gravimetrically by decreasing the temperature to bring the medium to a solution phase.

  2. ASI: Dunaliella Marine Microalgae to Drop-In Replacement Liquid Transportation Fuel

    Science.gov (United States)

    Microalgae are a promising biofuels feedstock, theoretically yielding concentrations of triacylglycerides (TAGs) per unit area far higher than traditional feedstocks due to their rapid growth. Dunaliella is particularly advantageous as a feedstock because it is currently commercially mass cultured,...

  3. Pigment production by a new thermotolerant microalga Coelastrella sp. F50.

    Science.gov (United States)

    Hu, Che-Wei; Chuang, Lu-Te; Yu, Po-Chien; Chen, Ching-Nen Nathan

    2013-06-15

    Microalgae are good crops to produce natural pigments because of their high growth rates. Tropical zones are better locations than temperate areas for microalgal cultivation because they have longer duration of daylight and more stable temperatures throughout the year, but the high temperatures pose a challenge to microalgal cultivation. A newly isolated thermotolerant microalga produces reddish pigments under environmental stress. Morphological and molecular evidence including meridional ribs on the cell wall, pigment production, and its 18S rDNA sequence suggests that this microalga belongs to the genus Coelastrella. Salt stress and high light intensity accelerated biosynthesis of the pigments, and significant quantities of oil accumulated as the cells experienced stress due to nutrient deficiency. This microalga could withstand temperature of 50°C for more than 8h, which is a necessary trait for outdoor cultivation in tropical areas. The pigments contain astaxanthin, lutein, canthaxanthin, and β-carotene as analysed by using HPLC.

  4. Cultivation and energy efficient harvesting of microalgae using thermoreversible sol-gel transition

    Science.gov (United States)

    Estime, Bendy; Ren, Dacheng; Sureshkumar, Radhakrishna

    2017-01-01

    Microalgae represent a promising source of renewable biomass for the production of biofuels and valuable chemicals. However, energy efficient cultivation and harvesting technologies are necessary to improve economic viability. A Tris-Acetate-Phosphate-Pluronic (TAPP) medium that undergoes a thermoreversible sol-gel transition is developed to efficiently culture and harvest microalgae without affecting the productivity as compared to that in traditional culture in a well-mixed suspension. After seeding microalgae in the TAPP medium in a solution phase at 15 °C, the temperature is increased by 7 °C to induce gelation. Within the gel, microalgae are observed to grow in large clusters rather than as isolated cells. The settling velocity of the microalgal clusters is approximately ten times larger than that of individual cells cultured in typical solution media. Such clusters are easily harvested gravimetrically by decreasing the temperature to bring the medium to a solution phase. PMID:28102313

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

    Science.gov (United States)

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

    2014-11-01

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

  6. Isolation and Characterization of Native Microalgae from the Peruvian Amazon with Potential for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Marianela Cobos

    2017-02-01

    Full Text Available Biodiesel production from microalgae triacylglycerols is growing, because this feedstock is a more sustainable and advantageous alternative. In this study, we isolated and identified fourteen strains of native microalgae from the Peruvian Amazon. These strains showed great heterogeneity in biomass productivity, lipid productivity and lipid content, and thus, three of them (Acutodesmus obliquus, Ankistrodesmus sp. and Chlorella lewinii were selected for further evaluation under culture of nitrogen-sufficient (+N and nitrogen-deficient (−N Chu medium No. 10. These microalgae species showed modifications in biomolecule content (protein, lipid and carbohydrate with a pronounced increase of lipids and carbohydrate and a decrease of protein content under stress culture. Furthermore, the fatty acid profile was peculiar for each species, and these patterns showed evident changes, particularly in the proportion of saturated and monounsaturated fatty acids. The results of this research suggest that the isolated native microalgae, from the Peruvian Amazon, could be suitable candidates for biodiesel production

  7. Influences of Natural Colloid in Seawater on the Growth of a Microalga

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Colloid concentrates were obtained by employing a cross-flow filtration system to ultrafiltrate seawater(which was pre-filtrated by 0.45 μm acetate cellulose membrane) sucessively with three membranes.The retentions (colloid concentrates) and control sample(in which colloid was removed)were then inoculated with a microalga and cultivated in vitro.After continuously monitoring cell content during cultivation,it was found that colloid had an obvious beneficial effect on the growth of microalga.Although colloids with different sizes influenced microalga's growth in different extent and ways,a brief conclusion could be draw from experiments that colloid might be a potential nutrition source for microalga's growth.

  8. Analysis of microalgae pellets combustion in a circulating fluidized-bed

    Directory of Open Access Journals (Sweden)

    Kosowska-Golachowska Monika

    2017-01-01

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

  9. A state of the art of metabolic networks of unicellular microalgae and cyanobacteria for biofuel production.

    Science.gov (United States)

    Baroukh, Caroline; Muñoz-Tamayo, Rafael; Steyer, Jean-Philippe; Bernard, Olivier

    2015-07-01

    The most promising and yet challenging application of microalgae and cyanobacteria is the production of renewable energy: biodiesel from microalgae triacylglycerols and bioethanol from cyanobacteria carbohydrates. A thorough understanding of microalgal and cyanobacterial metabolism is necessary to master and optimize biofuel production yields. To this end, systems biology and metabolic modeling have proven to be very efficient tools if supported by an accurate knowledge of the metabolic network. However, unlike heterotrophic microorganisms that utilize the same substrate for energy and as carbon source, microalgae and cyanobacteria require light for energy and inorganic carbon (CO2 or bicarbonate) as carbon source. This double specificity, together with the complex mechanisms of light capture, makes the representation of metabolic network nonstandard. Here, we review the existing metabolic networks of photoautotrophic microalgae and cyanobacteria. We highlight how these networks have been useful for gaining insight on photoautotrophic metabolism.

  10. Effects of petroleum hydrocarbons on the growth of a microalga, Isochrysis sp. (Chrysophyta)

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Saldanha, M.C.; Rajkumar, R.

    Effects of water soluble fraction of Bombay High crude oil and heavy duty marine diesel on the growth of a microalga were examined and compared. Most concentrations of the oil depressed the growth rate in Isochrysis sp. Marine diesel prevented...

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Tao Li

    2016-09-01

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

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

    Science.gov (United States)

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

    2016-09-07

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

  14. Concurrent extraction and reaction for the production of biodiesel from wet microalgae.

    Science.gov (United States)

    Im, Hanjin; Lee, HanSol; Park, Min S; Yang, Ji-Won; Lee, Jae W

    2014-01-01

    This work addresses a reliable in situ transesterification process which integrates lipid extraction from wet microalgae, and its conversion to biodiesel, with a yield higher than 90 wt.%. This process enables single-step production of biodiesel from microalgae by mixing wet microalgal cells with solvent, methanol, and acid catalyst; and then heating them in one pot. The effects of reaction parameters such as reaction temperature, wet cell weight, reaction time, and catalyst volume on the conversion yield are investigated. This simultaneous extraction and transesterification of wet microalgae may enable a significant reduction in energy consumption by eliminating the drying process of algal cells and realize the economic production of biodiesel using wet microalgae.

  15. Design and analysis of a second and third generation biorefinery: The case of castorbean and microalgae.

    Science.gov (United States)

    Moncada, Jonathan; Cardona, Carlos A; Rincón, Luis E

    2015-12-01

    In this work, a biorefinery system including castor bean seeds and microalgae is used as a case study to evaluate the integration of second and third generation biorefineries. A biorefinery concept was applied for the combined production of polyol, ethylene-glycol, omega-3 acid, biodiesel, methanol and heat and power from castor bean and microalgae. Castor bean cake and microalgae paste were used to feed a biomass-fired system (BIGCC), where part of CO2 produced in flue gas is captured and employed as substrate for microalgae growth. To evaluate the performance of this biorefinery concept three scenarios based on different levels of mass and energy integration were modeled and assessed from techno-economic and environmental points of view. The scenario with the best economic and environmental performances was the one including full mass integration, full heat integration, and cogeneration scheme.

  16. Cell-wall disruption and lipid/astaxanthin extraction from microalgae: Chlorella and Haematococcus.

    Science.gov (United States)

    Kim, Dong-Yeon; Vijayan, Durairaj; Praveenkumar, Ramasamy; Han, Jong-In; Lee, Kyubock; Park, Ji-Yeon; Chang, Won-Seok; Lee, Jin-Suk; Oh, You-Kwan

    2016-01-01

    Recently, biofuels and nutraceuticals produced from microalgae have emerged as major interests, resulting in intensive research of the microalgal biorefinery process. In this paper, recent developments in cell-wall disruption and extraction methods are reviewed, focusing on lipid and astaxanthin production from the biotechnologically important microalgae Chlorella and Haematococcus, respectively. As a common, critical bottleneck for recovery of intracellular components such as lipid and astaxanthin from these microalgae, the composition and structure of rigid, thick cell-walls were analyzed. Various chemical, physical, physico-chemical, and biological methods applied for cell-wall breakage and lipid/astaxanthin extraction from Chlorella and Haematococcus are discussed in detail and compared based on efficiency, energy consumption, type and dosage of solvent, biomass concentration and status (wet/dried), toxicity, scalability, and synergistic combinations. This report could serve as a useful guide to the implementation of practical downstream processes for recovery of valuable products from microalgae including Chlorella and Haematococcus.

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

    Science.gov (United States)

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

    2015-05-01

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

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

    Science.gov (United States)

    Peng, Xiaowei; Ma, Xiaoqian; Xu, Zhibin

    2015-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  20. Isolation, Characterization and Identification of Microalgae from the Red Sea

    KAUST Repository

    Luque Alanís, Patricio

    2013-05-01

    Eukaryotic microalgae from the Red Sea were isolated, characterized and identified with the purpose of building a culture collection that will serve future research activities in the area of industrial microbiology. Seven sampling locations were surveyed using an in-house designed isolation protocol. Microalgae enrichment was carried out in vitro using the streak plate method and fluorescence activated cell sorting approaches. Colonial and cellular microscopy, growth media preference assays, as well as temperature, pH and salinity tolerance tests were carried out to describe the isolates. DNA extraction, PCR amplification, template sequencing and in silico analyses were carried out to identify the isolates and arrange them in a proper phylogenetic description. In total, 129 isolates were obtained. From these, only 39 were selected for characterization given their increased ability of accumulating large amounts of biomass in solid and liquid media in relatively short periods of time. All of these have a green color, are unicellular, non-motile, photosynthetic organisms and have a cell size ranging from 5 to 8 µm. More than half of them showed growth preference in Walne media, followed by F/2, MN and BG-11 SW. Maximum temperature tolerance of all organisms was around 38 ºC, while optimum growth was observed close to 25 ºC. pH preference was diverse and three groups were identified: acidic (6), intermediate (8 - 9) and alkaline (> 10) growing isolates. Salinity tests showed an overall growth preference at 25 PSU, approximately 10 units lower than that found at the sampling stations. Most isolates showed diminished growth at high salinity and high pH, except for OS3S1b which grew well in both cases, and could be an interesting strain to study further. Twenty four isolates were related to Ulvophyceae sp. MBIC10591 by BLAST approaches with a maximum identity of 96 - 97%. A maximum likelihood phylogenetic tree was created for these isolates, relative to the BLAST hits

  1. Sustainable Hydrogen Photoproduction by Phosphorus-Deprived Marine Green Microalgae Chlorella sp.

    Directory of Open Access Journals (Sweden)

    Khorcheska Batyrova

    2015-01-01

    Full Text Available Previously it has been shown that green microalga Chlamydomonas reinhardtii is capable of prolonged H2 photoproduction when deprived of sulfur. In addition to sulfur deprivation (-S, sustained H2 photoproduction in C. reinhardtii cultures can be achieved under phosphorus-deprived (-P conditions. Similar to sulfur deprivation, phosphorus deprivation limits O2 evolving activity in algal cells and causes other metabolic changes that are favorable for H2 photoproduction. Although significant advances in H2 photoproduction have recently been realized in fresh water microalgae, relatively few studies have focused on H2 production in marine green microalgae. In the present study phosphorus deprivation was applied for hydrogen production in marine green microalgae Chlorella sp., where sulfur deprivation is impossible due to a high concentration of sulfates in the sea water. Since resources of fresh water on earth are limited, the possibility of hydrogen production in seawater is more attractive. In order to achieve H2 photoproduction in P-deprived marine green microalgae Chlorella sp., the dilution approach was applied. Cultures diluted to about 0.5–1.8 mg Chl·L−1 in the beginning of P-deprivation were able to establish anaerobiosis, after the initial growth period, where cells utilize intracellular phosphorus, with subsequent transition to H2 photoproduction stage. It appears that marine microalgae during P-deprivation passed the same stages of adaptation as fresh water microalgae. The presence of inorganic carbon was essential for starch accumulation and subsequent hydrogen production by microalgae. The H2 accumulation was up to 40 mL H2 gas per 1iter of the culture, which is comparable to that obtained in P-deprived C. reinhardtii culture.

  2. Influence of temperature and nutrient content on lipid production in freshwater microalgae cultures

    OpenAIRE

    BOHNENBERGER,JULIANA E.; LUCIANE O. CROSSETTI

    2014-01-01

    The production of biomass by microalgae is considered a clean alternative compared to other plant crops that require large areas for cultivation and that generate environmental impacts. This study evaluated the influence of temperature and nutrients on lipid contents of cultured species of freshwater microalgae, with a view toward using these lipids for biodiesel production. Two strains of Monoraphidium contortum, a culture containing Chlorella vulgaris and Desmodesmus quadricauda and another...

  3. Sustainable production of microalgae biomass in liquid digestates and by products from agro-food industries

    OpenAIRE

    Massa, Marina

    2016-01-01

    Globally, there is growing interest in microalgae production as innovative vegetable biomass rich in phytochemicals at high added value to apply in different commercial sectors (food, feed, nutraceutical, cosmetician and wastewaters depuration) and as future biodiesel source for the high lipid content and fatty acid profile of some species. To date the microalgae market for food and feed is a niche market but it is increasingly relevant and strictly correlate to their chemical com...

  4. Microplate-based method for high-throughput screening of microalgae growth potential

    DEFF Research Database (Denmark)

    Van Wagenen, Jonathan; Holdt, Susan Løvstad; De Francisci, Davide

    2014-01-01

    Microalgae cultivation conditions in microplates will differ from large-scale photobioreactors in crucial parameters such as light profile, mixing and gas transfer. Hence volumetric productivity (Pv) measurements made in microplates cannot be directly scaled up. Here we demonstrate that it is pos......Microalgae cultivation conditions in microplates will differ from large-scale photobioreactors in crucial parameters such as light profile, mixing and gas transfer. Hence volumetric productivity (Pv) measurements made in microplates cannot be directly scaled up. Here we demonstrate...

  5. Potentials of converting microalgae into brine shrimp Artemia

    OpenAIRE

    Sorgeloos, P.

    1985-01-01

    High densities of brine shrimp Artemia can be cultured in flow-through systems using the effluent of microalgae cultures as a combined source of culture medium and food. It has been proven at the "St. Croix Artificial Upwelling Mariculture Project" that in comparison with the fast growing clam Tapes japonica, brine shrimp assure a much more efficient conversion of plant into animal biomass. It appears from the given examples that microalgae conversion into brine shrimp Artemia offers efficien...

  6. Enzyme-Assisted Extraction of Oil from Wet Microalgae Scenedesmus sp. G4

    OpenAIRE

    Shuhao Huo; Zhongming Wang; Fengjie Cui; Bin Zou; Pengxiang Zhao; Zhenhong Yuan

    2015-01-01

    The enzyme-assisted aqueous extraction of oil from wet microalgae was employed to avoid the energy consumption of a dewatering process. In this paper, oil-rich microalgae Scenedesmus sp. G4 was hydrolyzed by enzyme mixtures for oil extraction. The results showed that the algae concentration had the greatest influence on yield of extracted oil, and the temperature and the ratio of enzyme mixtures affected the results as follows: the maximum yield of oil extracted from Scenedesmus sp. G4 reache...

  7. Biodiesel Production from Selected Microalgae Strains and Determination of its Properties and Combustion Specific Characteristics

    OpenAIRE

    Kokkinos, N.; A. Lazaridou; N. STAMATIS; Orfanidis, S.; A. Ch. Mitropoulos; A. Christoforidis; Nikolaou, N.

    2015-01-01

    Biofuels are gaining importance as significant substitutes for the depleting fossil fuels. Recent focus is on microalgae as the third generation feedstock. In the present research work, two indigenous fresh water and two marine Chlorophyte strains have been cultivated successfully under laboratory conditions using commercial fertilizer (Nutrileaf 30-10-10, initial concentration=70 g/m3 ) as nutrient source. Gas chromatographic analysis data showed that microalgae biodiesel obta...

  8. Função hepática e renal de frangos de corte alimentados com dietas com aflatoxinas e clinoptilolita natural

    OpenAIRE

    Maciel,Roberto Marinho; Lopes,Sonia Terezinha dos Anjos; Santurio,Janio Morais; Martins,Danieli Brolo; Rosa,Alexandre Pires; Emanuelli,Mauren Picada

    2008-01-01

    O objetivo deste trabalho foi avaliar os minerais séricos e as funções hepática e renal de frangos de corte, alimentados com dietas com aflatoxinas e dietas com aflatoxinas e argila clinoptilolita natural. Foram utilizados 528 frangos de corte machos, da linhagem Ross, distribuídos em seis tratamentos com quatro repetições cada: T1 - testemunha: ração sem aflatoxina ou clinoptilolita; T2 - ração com 5 ppm de aflatoxinas; T3 - ração com 0,25% de clinoptilolita; T4 - ração com 5 ppm de aflatoxi...

  9. BOVINE CATTLE FED WITH BRACHIARIA AND ANDROPOGON GRASS: HEMATOLOGY AND CLINICAL BIOCHEMISTRY BOVINOS ALIMENTADOS COM CAPIM BRACHIARIA E ANDROPOGON: HEMATOLOGIA E BIOQUÍMICA CLÍNICA

    Directory of Open Access Journals (Sweden)

    Mitsue Haragushi

    2009-04-01

    alimentados com capim Brachiaria brizantha e B. decumbens em uma mesma pastagem e Andropogon gayanus, correlacionando-as com o ganho em peso. Cinquenta bovinos foram divididos em dois grupos de 25 animais, alimentados com um dos dois gêneros de capim do desmame ao abate. Durante trinta meses foram realizadas colheitas das amostras de sangue, pesagem e exame clínico dos animais a cada sessenta dias aproximadamente. Do mesmo modo, colheram-se amostras das gramíneas nos mesmos períodos. A quantidade de esporos do fungo P. chartarum e a concentração de saponinas litogênicas das pastagens foram determinadas para comparação com a bioquímica clínica. Nenhum animal apresentou alterações clínicas, no entanto, o ganho de peso foi maior nos bovinos do grupo alimentado com A. gayanus. A concentração de hemoglobina, hematócrito, número de hemácias, bilirrubina total e indireta tiveram correlação com o ganho em peso dos animais. Os bovinos alimentados com Brachiaria spp. e A. gayanus apresentaram perfil hematológico e de função hepática semelhantes. Ao longo do período experimental, independente do tipo de capim ingerido pelos bovinos, ocorreu um aumento da AST, GGT e bilirrubinas, acompanhado de ausência de sinais clínicos, sugerindo presença de alteração hepática crônica subclínica.

    PALAVRAS-CHAVES: Aspartato aminotransferase, esporidesmina, fotossensibilização, gama glutamiltransferase, saponina.

  10. Desempenho e exigências nutricionais de bovinos alimentados com dietas contendo diferentes níveis de cálcio e fósforo

    OpenAIRE

    Prados,Laura Franco

    2012-01-01

    O presente trabalho foi desenvolvido com o objetivo de avaliar o consumo, a digestibilidade e o desempenho de bovinos cruzados ¾ Zebu × ¼ Holandês, alimentados com três níveis de cálcio e fósforo na dieta; estimar as exigências nutricionais de energia e proteína de bovinos cruzados ¾ Zebu × ¼ Holandês, não castrados; e testar equações para predição da composição química corporal da carcaça, dos componentes não-carcaça e do corpo vazio obtidas por Hankins & Howe (1946) e pelo BR-CORTE (2006 e ...

  11. A comparative study of bio-oils from pyrolysis of microalgae and oil seed waste in a fluidized bed.

    Science.gov (United States)

    Kim, Sung Won; Koo, Bon Seok; Lee, Dong Hyun

    2014-06-01

    The pyrolysis of Scenedesmus sp. and Jatropha seedshell cake (JSC) was investigated under similar operating condition in a fluidized bed reactor for comparison of pyrolytic behaviors from different species of lipids-containing biomass. Microalgae showed a narrower main peak in differential thermogravimetric curve compared to JSC due to different constituents. Pyrolysis liquid yields were similar; liquid's oil proportion of microalgae is higher than JSC. Microalgae bio-oil was characterized by similar carbon and hydrogen contents and higher H/C and O/C molar ratios compared to JSC due to compositional difference. The pyrolytic oils from microalgae and JSC contained more oxygen and nitrogen and less sulfur than petroleum and palm oils. The pyrolytic oils showed high yields of fatty oxygenates and nitrogenous compounds. The microalgae bio-oil features in high concentrations of aliphatic compounds, fatty acid alkyl ester, alcohols and nitriles. Microalgae showed potentials for alternative feedstock for green diesel, and commodity and valuable chemicals.

  12. Bioprospecting for acidophilic lipid-rich green microalgae isolated from abandoned mine site water bodies.

    Science.gov (United States)

    Eibl, Joseph K; Corcoran, Jason D; Senhorinho, Gerusa N A; Zhang, Kejian; Hosseini, Nekoo Seyed; Marsden, James; Laamanen, Corey A; Scott, John A; Ross, Gregory M

    2014-03-26

    With fossil fuel sources in limited supply, microalgae show tremendous promise as a carbon neutral source of biofuel. Current microalgae biofuel strategies typically rely on growing high-lipid producing laboratory strains of microalgae in open raceways or closed system photobioreactors. Unfortunately, these microalgae species are found to be sensitive to environmental stresses or competition by regional strains. Contamination by invasive species can diminish productivity of commercial algal processes. A potential improvement to current strategies is to identify high-lipid producing microalgae, which thrive in selected culture conditions that reduce the risk of contamination, such as low pH. Here we report the identification of a novel high-lipid producing microalgae which can tolerate low pH growth conditions. Lig 290 is a Scenedesmus spp. isolated from a low pH waterbody (pH = 4.5) in proximity to an abandoned lignite mine in Northern Ontario, Canada. Compared to a laboratory strain of Scendesmus dimorphus, Lig 290 demonstrated robust growth rates, a strong growth profile, and high lipid production. As a consequence, Lig 290 may have potential application as a robust microalgal species for use in biofuel production.

  13. Perspectives on engineering strategies for improving biofuel production from microalgae--a critical review.

    Science.gov (United States)

    Ho, Shih-Hsin; Ye, Xiaoting; Hasunuma, Tomohisa; Chang, Jo-Shu; Kondo, Akihiko

    2014-12-01

    Although the potential for biofuel production from microalgae via photosynthesis has been intensively investigated, information on the selection of a suitable operation strategy for microalgae-based biofuel production is lacking. Many published reports describe competitive strains and optimal culture conditions for use in biofuel production; however, the major impediment to further improvements is the absence of effective engineering strategies for microalgae cultivation and biofuel production. This comprehensive review discusses recent advances in understanding the effects of major environmental stresses and the characteristics of various engineering operation strategies on the production of biofuels (mainly biodiesel and bioethanol) using microalgae. The performances of microalgae-based biofuel-producing systems under various environmental stresses (i.e., irradiance, temperature, pH, nitrogen depletion, and salinity) and cultivation strategies (i.e., fed-batch, semi-continuous, continuous, two-stage, and salinity-gradient) are compared. The reasons for variations in performance and the underlying theories of the various production strategies are also critically discussed. The aim of this review is to provide useful information to facilitate development of innovative and feasible operation technologies for effectively increasing the commercial viability of microalgae-based biofuel production.

  14. Antioxidant activity of some Moroccan marine microalgae: Pufa profiles, carotenoids and phenolic content.

    Science.gov (United States)

    Maadane, Amal; Merghoub, Nawal; Ainane, Tarik; El Arroussi, Hicham; Benhima, Redouane; Amzazi, Saaid; Bakri, Youssef; Wahby, Imane

    2015-12-10

    In order to promote Moroccan natural resources, this study aims to evaluate the potential of microalgae isolated from Moroccan coastlines, as new source of natural antioxidants. Different extracts (ethanolic, ethanol/water and aqueous) obtained from 9 microalgae strains were screened for their in vitro antioxidant activity using DPPH free radical-scavenging assay. The highest antioxidant potentials were obtained in Dunalliela sp., Tetraselmis sp. and Nannochloropsis gaditana extracts. The obtained results indicate that ethanol extract of all microalgae strains exhibit higher antioxidant activity, when compared to water and ethanol/water extracts. Therefore, total phenolic and carotenoid content measurement were performed in active ethanol extracts. The PUFA profiles of ethanol extracts were also determined by GC/MS analysis. The studied microalgae strains displayed high PUFA content ranging from 12.9 to 76.9 %, total carotenoids content varied from 1.9 and 10.8mg/g of extract and total polyphenol content varied from 8.1 to 32.0mg Gallic acid Equivalent/g of extract weight. The correlation between the antioxidant capacities and the phenolic content and the carotenoids content were found to be insignificant, indicating that these compounds might not be major contributor to the antioxidant activity of these microalgae. The microalgae extracts exerting the high antioxidant activity are potential new source of natural antioxidants.

  15. Joint production of biodiesel and bioethanol from filamentous oleaginous microalgae Tribonema sp.

    Science.gov (United States)

    Wang, Hui; Ji, Chunli; Bi, Shenglei; Zhou, Peng; Chen, Lin; Liu, Tianzhong

    2014-11-01

    Making full use of lipid and carbohydrate in microalgae for joint production of biodiesel and bioethanol may create a potential way to cut the high cost of single biofuel production from microalgae. Compared with conventional unicellular oleaginous microalgae, filamentous microalgae Tribonema sp. is richer in lipid and carbohydrate contents and lower protein content, thus, this study explores the suitability of Tribonema sp. as a substrate for joint production of biodiesel and bioethanol. Acid hydrolysis is the key step to saccharify wall cell into fermentable sugar and release lipid. Microalgae biomass (50g/L) was acid (3% H2SO4) hydrolyzed at 121°C for 45min to reach the maximum hydrolysis efficiency (81.48%). Subsequently, the lipid separated with hexane-ethanol from the hydrolysate was converted into microalgae biodiesel and the conversion rate was 98.47%. With yeast Saccharomyces cerevisiae, the maximum ethanol yield of 56.1% was reached from 14.5g/L glucose in hydrolysate.

  16. Growth inhibition to three red tide microalgae by extracts of Ulva pertusa

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Growth inhibition effect of different concentration of distilled water extract and four polar organic solvent (methanol, acetone, ether and chloroform) extracts of Ulva pertusa on three typical red tide microalgae (Heterosigma akashiwo, Alexandrium tamarense and Prorocentrum micans) were investigated. Liquid-liquid fractionation and HPLC analysis for methanol extract of U. pertusa were carried out.Growth of the three microalgae was significantly inhibited by the distilled water extract of U. pertusa at relatively higher concentration. However, the cells of the three microalgae did not die completely even at high concentration. Methanol extract of U. pertusa showed the highest growth inhibition on the three microalgae, and all the cells of the three microalgae were killed at relatively high concentration. The other three organic solvent extracts of U. pertusa had no apparent effect on the three microalgae. The results of bioassays and HPLC analysis suggested that the inhibitory substances in U. pertusa to the microalgal growth had relatively high polarities. H. akashiwo was the most sensitive one while A. tamarense was the most tolerant one to the growth inhibitory substances.

  17. Evaluation of the volatile composition and sensory properties of five species of microalgae.

    Science.gov (United States)

    Van Durme, Jim; Goiris, Koen; De Winne, Ann; De Cooman, Luc; Muylaert, Koenraad

    2013-11-20

    Due to their high content of polyunsaturated fatty acids, antioxidants, and proteins, microalgae hold a lot of potential for nutritional applications. When microalgae are integrated into foodstuffs, the aroma is an important aspect to consider. In this study the aroma properties of microalgae were studied by correlating data on the volatile composition with sensory evaluations. Four species of marine microalgae ( Botryococcus braunii, , Rhodomonas , Tetraselmis species, and Nannochloropsis oculata ) and one fresh water microalga ( Chlorella vulgaris ) were investigated. Multivariate data processing revealed that microalgal samples having a seafood-like odor character contain high levels of sulfuric compounds (dimethyl disulfide, dimethyl trisulfide, and methional), diketones, α-ionone, and β-ionone. Fresh green, fruity flavors were linked with typical aldehydes such as 2,4-alkadienals and 2,4,6-alkatrienals. The presence of these compounds in fresh microalga pastes is explained by aroma formation mechanisms such as enzymatic lipid oxidation, enzymatic and chemical degradation of dimethylsulfoniopropionate (generating dimethyl sulfide), phenylalanine (generating benzaldehyde), and carotenoids (generating ionones).

  18. Microalgae biofuels: A critical review of issues, problems and the way forward.

    Science.gov (United States)

    Lam, Man Kee; Lee, Keat Teong

    2012-01-01

    Culturing of microalgae as an alternative feedstock for biofuel production has received a lot of attention in recent years due to their fast growth rate and ability to accumulate high quantity of lipid and carbohydrate inside their cells for biodiesel and bioethanol production, respectively. In addition, this superior feedstock offers several environmental benefits, such as effective land utilization, CO(2) sequestration, self-purification if coupled with wastewater treatment and does not trigger food versus fuel feud. Despite having all these 'theoretical' advantages, review on problems and issues related to energy balance in microalgae biofuel are not clearly addressed until now. Base on the maturity of current technology, the true potential of microalgae biofuel towards energy security and its feasibility for commercialization are still questionable. Thus, this review is aimed to depict the practical problems that are facing the microalgae biofuel industry, covering upstream to downstream activities by accessing the latest research reports and critical data analysis. Apart from that, several interlink solutions to the problems will be suggested with the purpose to bring current microalgae biofuel research into a new dimension and consequently, to revolutionize the entire microalgae biofuel industry towards long-term sustainability.

  19. Net energy and greenhouse gas emission evaluation of biodiesel derived from microalgae.

    Science.gov (United States)

    Batan, Liaw; Quinn, Jason; Willson, Bryan; Bradley, Thomas

    2010-10-15

    Biofuels derived from microalgae have the potential to replace petroleum fuel and first-generation biofuel, but the efficacy with which sustainability goals can be achieved is dependent on the lifecycle impacts of the microalgae-to-biofuel process. This study proposes a detailed, industrial-scale engineering model for the species Nannochloropsis using a photobioreactor architecture. This process level model is integrated with a lifecycle energy and greenhouse gas emission analysis compatible with the methods and boundaries of the Argonne National Laboratory GREET model, thereby ensuring comparability to preexisting fuel-cycle assessments. Results are used to evaluate the net energy ratio (NER) and net greenhouse gas emissions (GHGs) of microalgae biodiesel in comparison to petroleum diesel and soybean-based biodiesel with a boundary equivalent to "well-to-pump". The resulting NER of the microalgae biodiesel process is 0.93 MJ of energy consumed per MJ of energy produced. In terms of net GHGs, microalgae-based biofuels avoids 75 g of CO(2)-equivalent emissions per MJ of energy produced. The scalability of the consumables and products of the proposed microalgae-to-biofuels processes are assessed in the context of 150 billion liters (40 billion gallons) of annual production.

  20. Marine Microalgae Tetraselmis suecica as Flocculant Agent of Bio-flocculation Method

    Directory of Open Access Journals (Sweden)

    Mujizat Kawaroe

    2016-04-01

    Full Text Available Microalgae harvesting is an important part in microalgae cultivation system. Techniques for harvesting marine microalgae which are commonly used are centrifugation, filtration and flocculation. These techniques still have some disadvantages, such as not environment friendly, and high usage of energy and cost. Bio-flocculation harvesting technique using microalgae as a flocculant agent can be an alternative way to solve these problems. In this research, mixing of Tetraselmis suecica (flocculant with Chlorella sp. and Nannochloropsis sp. (non-flocculant in ratios of 1:4, 2:4, 3:4 and 4:4 (v/v has been conducted to obtain percent recovery of marine microalgae harvest. The results showed that T. suecica as flocculant agent can fasten the harvesting of Chlorella sp. and Nannochloropsis sp. It was shown by the increase of percent recovery value of Chlorella sp. from 51.14 ± 1.07% to 67.34 ± 0.67% and Nannochloropsis sp. from 20.52 ± 1.17% to 42.43 ± 0.40% during the first hour of flocculating process. Our result showed that bio-flocculation is an environment friendly technique which can be applied to harvest marine microalgae.

  1. The potential of transgenic green microalgae; a robust photobioreactor to produce recombinant therapeutic proteins.

    Science.gov (United States)

    Akbari, Fariba; Eskandani, Morteza; Khosroushahi, Ahmad Yari

    2014-11-01

    Microalgae have been used in food, cosmetic, and biofuel industries as a natural source of lipids, vitamins, pigments and antioxidants for a long time. Green microalgae, as potent photobioreactors, can be considered as an economical expression system to produce recombinant therapeutical proteins at large-scale due to low cost of production and scaling-up capitalization owning to the inexpensive medium requirement, fast growth rate, and the ease of manipulation. These microalgae possess all benefit eukaryotic expression systems including the ability of post-translational modifications required for proper folding and stability of active proteins. Among the many items regarded as recombinant protein production, this review compares the different expression systems with green microalgae like Dunaliella by viewing the nuclear/chloroplast transformation challenges/benefits, related selection markers/reporter genes, and crucial factors/strategies affecting the increase of foreign protein expression in microalgae transformants. Some important factors were discussed regarding the increase of protein yielding in microalgae transformants including: transformation-associated genotypic modifications, endogenous regulatory factors, promoters, codon optimization, enhancer elements, and milking of recombinant protein.

  2. Biodiesel Fuel Production from Marine Microalgae Isochrysis galbana, Pavlova lutheri, Dunaliella salina and Measurement of its Viscosity and Density

    OpenAIRE

    T. Sujin Jeba Kumar; C.K. Balavigneswaran; K.P. Srinivasakumar

    2013-01-01

    Biodiesel is a fuel derives from transesterification of fats and oils. It is renewable and non-toxic ecofriendly fuel with less CO2 and NO2 emissions. Microalgae are known to contain more lipid content than macroalgae and most other oil crops. In this study, we extracted biodiesel from three microalgae Isochrysis galbana, Pavlova lutheri, Dunaliella salina and also measured the density and viscosity of biofuel obtained from these microalgae. Pavlova lutheri yielded more oil than the other two...

  3. Evaluation of hydrolysis-esterification biodiesel production from wet microalgae.

    Science.gov (United States)

    Song, Chunfeng; Liu, Qingling; Ji, Na; Deng, Shuai; Zhao, Jun; Li, Shuhong; Kitamura, Yutaka

    2016-08-01

    Wet microalgae hydrolysis-esterification route has the advantage to avoid the energy-intensive units (e.g. drying and lipid extraction) in the biodiesel production process. In this study, techno-economic evaluation of hydrolysis-esterification biodiesel production process was carried out and compared with conventional (usually including drying, lipid extraction, esterification and transesterification) biodiesel production process. Energy and material balance of the conventional and hydrolysis-esterification processes was evaluated by Aspen Plus. The simulation results indicated that drying (2.36MJ/L biodiesel) and triolein transesterification (1.89MJ/L biodiesel) are the dominant energy-intensive stages in the conventional route (5.42MJ/L biodiesel). By contrast, the total energy consumption of hydrolysis-esterification route can be reduced to 1.81MJ/L biodiesel, and approximately 3.61MJ can be saved to produce per liter biodiesel.

  4. An overview: biomolecules from microalgae for animal feed and aquaculture.

    Science.gov (United States)

    Yaakob, Zahira; Ali, Ehsan; Zainal, Afifi; Mohamad, Masita; Takriff, Mohd Sobri

    2014-12-01

    Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of biomolecules and biomass for feed purposes. Algae farming can be established using land as well as sea and strategies can be designed in order to gain the products of specific interest in the optimal way. A general overview of the contributions of Algae to meet the requirements of nutrients in animal/aquaculture feed is presented in this study. In addition to its applications in animal/aquaculture feed, algae can produce a number of biomolecules including astaxanthin, lutein, beta-carotene, chlorophyll, phycobiliprotein, Polyunsaturated Fatty Acids (PUFAs), beta-1,3-glucan, and pharmaceutical and nutraceutical compounds which have been reviewed with respect to their commercial importance and current status. The review is further extended to highlight the adequate utilization of value added products in the feeds for livestock, poultry and aquaculture (with emphasis in shrimp farming).

  5. Understanding nitrate assimilation and its regulation in microalgae.

    Science.gov (United States)

    Sanz-Luque, Emanuel; Chamizo-Ampudia, Alejandro; Llamas, Angel; Galvan, Aurora; Fernandez, Emilio

    2015-01-01

    Nitrate assimilation is a key process for nitrogen (N) acquisition in green microalgae. Among Chlorophyte algae, Chlamydomonas reinhardtii has resulted to be a good model system to unravel important facts of this process, and has provided important insights for agriculturally relevant plants. In this work, the recent findings on nitrate transport, nitrate reduction and the regulation of nitrate assimilation are presented in this and several other algae. Latest data have shown nitric oxide (NO) as an important signal molecule in the transcriptional and posttranslational regulation of nitrate reductase and inorganic N transport. Participation of regulatory genes and proteins in positive and negative signaling of the pathway and the mechanisms involved in the regulation of nitrate assimilation, as well as those involved in Molybdenum cofactor synthesis required to nitrate assimilation, are critically reviewed.

  6. A solar photobioreactor for the production of biohydrogen from microalgae

    Science.gov (United States)

    Panti, Luis; Chávez, Pedro; Robledo, Daniel; Patiño, Rodrigo

    2007-09-01

    The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost system using the solar radiation in Yucatan, Mexico. A two-step process is necessary with a closed photobioreactor, in which the algae are firstly growth and then induced for hydrogen generation. Preliminary results are presented in this work with some planning for the future. Different culture broths, temperatures and light intensities were tested for biomass and hydrogen production in laboratory conditions. The first experiments in external conditions with solar radiation and without temperature control have been performed, showing the potential of this technique at larger scales. However, some additional work must be done in order to optimize the culture maintenance, particularly in relation with the temperature control, the light radiation and the carbon dioxide supply, with the idea of keeping an economic production.

  7. Photoacclimation state determines the photobehaviour of motile microalgae

    DEFF Research Database (Denmark)

    Ezequiel, João; Laviale, Martin; Frankenbach, Silja

    2015-01-01

    High productivity in intertidal microphytobenthic communities is achieved despite exposure to extreme and dynamic conditions (e.g. light, salinity, temperature). As an adaptation to this hostile environment, most of the microalgae species inhabiting fine-sediment habitats are motile, being able...... in both cases, cells avoided extreme low and high light levels, maximum cell accumulation was reached at markedly different light intensities depending on growth light conditions and resulting photoacclimation state: 72 and 104μmolquantam-2s-1 for the low and high light-acclimated cells, respectively...... to migrate vertically within the uppermost layers of the sediment and actively regulating their exposure to light. In this work we tested the hypothesis that the migratory photobehaviour of benthic diatoms, the dominant group in microphytobenthic assemblages, is conditioned by their photophysiological state...

  8. Understanding nitrate assimilation and its regulation in microalgae

    Directory of Open Access Journals (Sweden)

    Emanuel eSanz-Luque

    2015-10-01

    Full Text Available Nitrate assimilation is a key process for nitrogen (N acquisition in green microalgae. Among Chlorophyte algae, Chlamydomonas reinhardtii has resulted to be a good model system to unravel important facts of this process, and has provided important insights for agriculturally relevant plants. In this work, the recent findings on nitrate transport, nitrate reduction and the regulation of nitrate assimilation are presented in this and several other algae. Latest data have shown nitric oxide (NO as an important signal molecule in the transcriptional and posttranslational regulation of nitrate reductase and inorganic N transport. Participation of regulatory genes and proteins in positive and negative signaling of the pathway and the mechanisms involved in the regulation of nitrate assimilation, as well as those involved in Molybdenum cofactor synthesis required to nitrate assimilation, are critically reviewed.

  9. Enzyme-assisted aqueous extraction of lipid from microalgae.

    Science.gov (United States)

    Liang, Kehong; Zhang, Qinghua; Cong, Wei

    2012-11-28

    An improved lipid extraction process has been established for microalgal using enzyme-assisted aqueous extraction processing (EAEP), which mainly involved in sonication and enzyme treatment. As compared to cellulase, neutral protease and alkaline protease, significantly higher lipid recovery was achieved by snailase and trypsin. The highest lipid recovery of 49.82% was obtained by a combined sonication-enzyme treatment at pH 4. The enhancement mechanism of the EAEP was analyzed in terms of the particle size of cream and zeta potential. In addition, microalgal lipid recovery was also affected by lipid class composition and the type of algae. The present study demonstrates a promising alternative to conventional lipid extraction of microalgae and the quantitative information on EAEP of oleaginous alga can provide valuable data for process design at pilot and industrial scale.

  10. Applications of Diatoms as Potential Microalgae in Nanobiotechnology

    Directory of Open Access Journals (Sweden)

    Ahmad Yari Khosroushahi

    2012-05-01

    Full Text Available Introduction: Diatoms are single cell eukaryotic microalgae, which present in nearly every water habitat make them ideal tools for a wide range of applications such as oil explora­tion, forensic examination, environmental indication, biosilica pattern generation, toxicity testing and eutrophication of aqueous ecosystems. Methods: Essential information on diatoms were reviewed and discussed towards impacts of diatoms on biosynthesis and bioremediation. Results: In this review, we present the recent progress in this century on the application of diatoms in waste degradation, synthesis of biomaterial, biomineraliza­tion, toxicity and toxic effects of mineral elements evaluations. Conclusion: Diatoms can be considered as metal toxicity bioindicators and they can be applied for biomineralization, synthesis of biomaterials, and degradation of wastes.

  11. Commercialization potential aspects of microalgae for biofuel production: An overview

    Directory of Open Access Journals (Sweden)

    Tahani S. Gendy

    2013-06-01

    This article discusses the importance of algae-based biofuels together with the different opinions regarding its future. Advantages and disadvantages of these types of biofuels are presented. Algal growth drives around the world with special emphasis to Egypt are outlined. The article includes a brief description of the concept of algal biorefineries. It also declares the five key strategies to help producers to reduce costs and accelerate the commercialization of algal biodiesel. The internal strengths and weaknesses, and external opportunities, and threats are manifested through the SWOT analysis for micro-algae. Strategies for enhancing algae based-fuels are outlined. New process innovations and the role of genetic engineering in meeting these strategies are briefly discussed. To improve the economics of algal biofuels the concept of employing algae for wastewater treatment is presented.

  12. Processing of Microalgae: Acoustic Cavitation and Hydrothermal Conversion

    Science.gov (United States)

    Greenly, Justin Michael

    The production of energy dense fuels from renewable algal biomass feedstocks -- if sustainably developed at a sufficiently large scale -- may reduce the consumption of petroleum from fossil fuels and provide many environmental benefits. Achieving economic feasibility has several technical engineering challenges that arise from dilute concentration of growing algae in aqueous media, small cell sizes, and durable cell walls. For microalgae to be a sustainable source of biofuels and co-products, efficient fractionation and conversion of the cellular contents is necessary. Research was carried out to address two processing options for efficient microalgae biofuel production: 1. Ultrasonic cavitation for cell disruption and 2. Hydrothermal conversion of a model algal triglyceride. 1. Ultrasonic cell disruption, which relies on cavitating bubbles in the suspension to produce damaging shock waves, was investigated experimentally over a range of concentrations and species types. A few seconds of high intensity sonication at fixed frequency yielded significant cell disruption, even for the more durable cells. At longer exposure times, effectiveness was seen to decline and was attributed, using acoustic measurements, to ultrasonic power attenuation in the ensuing cloud of cavitating bubbles. Processing at higher cell concentrations slowed cell disintegration marginally, but increased the effectiveness of dissipating ultrasonic energy. A theoretical study effectively predicted optimal conditions for a variety of parameters that were inaccessible in this experimental investigation. In that study, single bubble collapse was modeled to identify operating conditions that would increase cavitation, and thus cell disruption. Simulations were conducted by varying frequency and pressure amplitude of the ultrasound wave, and initial bubble size. The simulation results indicated that low frequency, high sound wave amplitudes, and small initial bubble size generate the highest shock

  13. Carotenoids of Microalgae Used in Food Industry and Medicine.

    Science.gov (United States)

    Gateau, Hélène; Solymosi, Katalin; Marchand, Justine; Schoefs, Benoît

    2016-08-08

    Since the industrial revolution, the consumption of processed food increased dramatically. During processing, food material loses many of its natural properties. The simple restoration of the original properties of the processed food as well as fortification require food supplementation with compounds prepared chemically or of natural origin. The observations that natural food additives are safer and better accepted by consumers than synthetic ones have strongly increased the demand for natural compounds. Because some of them have only a low abundance or are even rare, their market price can be very high. This is the case for most carotenoids of natural origin to which this review is dedicated. The increasing demand for food additives of natural origin contributes to an accelerated depletion of traditional natural resources already threatened by intensive agriculture and pollution. To overcome these difficulties and satisfy the demand, alternative sources for natural carotenoids have to be found. In this context, photosynthetic microalgae present a very high potential because they contain carotenoids and are able to produce particular carotenoids under stress. Their potential also resides in the fact that only ten thousands of microalgal strains have been described while hundred thousands of species are predicted to exist. Carotenoids have been known for ages for their antioxidant and coloring properties, and a large body of evidence has been accumulated about their health potential. This review summarizes both the medicinal and food industry applications of microalgae with emphasis on the former. In addition, traditional and alternative, microalgal sources for industrial carotenoid extraction, the chemical and physical properties, the biosynthesis and the localization of carotenoids in algae are also briefly discussed.

  14. Isolation and Characterisation of Some Microalgae Bioactive Molecules

    Directory of Open Access Journals (Sweden)

    Emeka Ugoala

    2016-12-01

    Full Text Available This study involved the isolation, structure elucidation, and biological screening of secondary metabolites in freshwater microalgae for bioactive and chemically novel compounds. Isolates were fractionated and purified from the methanol, ethyl acetate, dichloromethane, petroleum ether and aqueous extracts of microalgae via column chromatography technique over silica gel using a gradient mixture of solvents. The chemical structures of isolated compounds have been elucidated using Solid-state cross polarization (CP and magic angle spinning (MAS 13C-NMR spectroscopic technique at spectrometer frequency at a field strength corresponding to 91.3695 MHz for 13C and 363.331 MHz for 1H. Of the nine compounds isolated, eight have a glycan skeleton with attached amino acids units. Two of the eight contain beta amino acids units. These are not very common metabolites but hold promise as drug leads. The elements of diversity in the isolates were the gluco and manno configurations of the pyranose ring, the α-configurations at the anomeric centre, and the positions of the carbohydrate and amino acid sectors in the ring. These molecules are not easily available through gene technology since they are post translational products resulting from the activity of glycosyl hydrolases and transferases. The chemical shifts were rationalized in terms of the number of sugar residues, the sugar ring structures, the positions and anomeric configurations of the inter-sugar linkages. Considering all the NMR data, it was concluded that the compounds were glycylglycylglycylglycine, α-D-glucopyranosyl-2-amino-4-methylpentanoic acid, α-D-glucopyranosyl-2-methylamino-4-methylpentanoic acid, α-D-glucopyranosyl-2-amino-4-methylpentanoate, α-D-glucopyranosyl-glycylglycine, α-D-glucopyranosyl-3-aminobutanoic acid, α-D-glucopyranosyl-2,4,7-triaminooctantrioic acid, α-D-mannopyranosyl-2-amino-3-methylbutanoic acid and α-D-mannopyranosyl-3-aminobutanoic acid.

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

    Science.gov (United States)

    Mathieu-Rivet, Elodie; Kiefer-Meyer, Marie-Christine; Vanier, Gaëtan; Ovide, Clément; Burel, Carole; Lerouge, Patrice; Bardor, Muriel

    2014-01-01

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

  16. Perfil de ácidos graxos de microalgas cultivadas com dióxido de carbono Fatty acids profile of microalgae cultived with carbon dioxide

    Directory of Open Access Journals (Sweden)

    Michele Greque de Morais

    2008-08-01

    Full Text Available As microalgas são consideradas fontes potenciais de diversos compostos químicos. Os ácidos graxos obtidos da biomassa podem apresentar efeitos terapêuticos em humanos e podem ser usados para produção de biodiesel. Objetivou-se, neste trabalho verificar o conteúdo lipídico e o perfil dos ácidos graxos das microalgas Spirulina sp., Scenedesmus obliquus, Chlorella kessleri e Chlorella vulgaris cultivadas em diferentes concentrações de dióxido de carbono e bicarbonato de sódio. A microalga Chlorella kessleri cultivada com 12% de CO2 apresentou a maior concentração de lipídios na biomassa seca (9,7% p/p. A máxima concentração de ácidos graxos insaturados foi 72,0% (p/p para C. vulgaris cultivada com 12% de CO2. Para os ácidos graxos saturados o maior valor encontrado foi 81,6% (p/p, quando a microalga Spirulina sp. foi cultivada com 18% de CO2 e 16,8 g.L-1 de bicarbonato de sódio.Microalgae have a great potential as a source of several chemical compounds. The fatty acids have shown therapeutic effects and used to produce biodiesel. The aim of this work was to verify the lipid contents and the fatty acids profile of the microalga Spirulina sp., Scenedesmus obliquus, Chlorella kessleri and Chlorella vulgaris cultived in different carbon dioxide and sodium bicarbonate concentrations. The microalgae Chlorella kessleri cultived with 12% CO2 showed the highest lipid content in the dry biomass (9.7% p/p. The maximum unsaturated fatty acids concentration was 72.0% (p/p to C. vulgaris in the culture with 12% CO2. The highest saturated fatty acids value was 81.6% (p/p when microalga Spirulina sp. was cultived with 18% CO2 and 16.8 g.L-1 sodium bicarbonate.

  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. The isolation and screening of microalgae for the production of oil

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    Danilović Bojana R.

    2017-01-01

    Full Text Available The biodiesel production has gained increasing attention of the researches in recent years. Current commercial biodiesel production involves transesterification of oil derived from oil crops. Since this production is no more sustainable, the use of microalgae represents a good alternative. Microalgae have high growth rate, high oil content and can be cultured in the environment which are not suitable for agriculture. Additionally, microalgae cultivation improves the reduction of carbon dioxide in the atmosphere. Selection of microalgae for oil production must take into consider certain criteria which include growth rate, oil content, fatty acids profile and ease of separation. In order to analyze the possibility of the use of microalgae for the production of oil, isolation of freshwater microalgae was performed. The isolation was done by the use of traditional techniques from freshwaters near Leskovac. A total number of 6 microalgae strains were isolated and identified as the representatives of the genera Chlorococcum (1 isolate, Chlorella (1 isolate, Scenedesmus (1 isolate and Desmodesmus (3 isolates. Isolates of microalgae were screened for the growth rate, biomass and oil productivity and oil content. The highest content of biomass was 1.5 g/l and it was observed in the strains Chlorococcum sp. and Desmodesmus sp. 1. The highest value of specific growth rate was calculated during the growth of microalgae Chlorella sp., Scenedesmus sp. and Desmodesmus sp.1, while the lowest value was observed for Chlorococcum sp. Oil productivity was the highest for Chlorella sp. and Desmodesmus sp.1 (0,4 g/l and the lowest for Desmodesmus sp.2, Desmodesmus sp.3 and Chlorococcum sp. (0,2 g/l. The oil content was in the range from 15.8% (Chlorococcum sp. to 33% (Chlorella sp. Since the microalgae isolates Chlorella sp. and Scenedesmus sp. had the highest oil productivity, high growth rate and high oil content, these strains are the most suitable for further

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

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

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    Carlos Vilchez

    2010-12-01

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

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

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    Mimouni Virginie

    2015-07-01

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

  2. Preventive effect of the microalga Chlamydomonas debaryana on the acute phase of experimental colitis in rats.

    Science.gov (United States)

    Avila-Román, Javier; Talero, Elena; Alcaide, Antonio; Reyes, Carolina de Los; Zubía, Eva; García-Mauriño, Sofía; Motilva, Virginia

    2014-10-14

    Inflammatory bowel diseases (IBD) are characterised by chronic uncontrolled inflammation of intestinal mucosa. Diet and nutritional factors have emerged as possible interventions for IBD. Microalgae are rich sources of n-3 PUFA and derived oxylipins. Oxylipins are lipid mediators involved in the resolution of many inflammatory disorders. The aim of the present study was to investigate the effects of the oxylipin-containing biomass of the microalga Chlamydomonas debaryana and its major oxylipin constituent, (9Z,11E,13S,15Z)-13-hydroxyoctadeca-9,11,15-trienoic acid ((13S)-HOTE), on acute 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. Lyophilised microalgal biomass and (13S)-HOTE were administered by oral route 48, 24 and 1 h before the induction of colitis and 24 h later, and the rats were killed after 48 h. The treatment with the lyophilised microalga and (13S)-HOTE improved body-weight loss and colon shortening, as well as attenuated the extent of colonic damage and increased mucus production. Cellular neutrophil infiltration, with the subsequent increase in myeloperoxidase levels induced by TNBS, were also reduced after the administration of the lyophilised microalga or (13S)-HOTE. The anti-inflammatory effects of these treatments were confirmed by the inhibition of colonic TNF-α production. Moreover, lyophilised microalga or (13S)-HOTE down-regulated cyclo-oxygenase-2 and inducible nitric oxide synthase expression. The present study was the first to show the prophylactic effects of a lyophilised biomass sample of the microalga C. debaryana and the oxylipin (13S)-HOTE on TNBS-induced acute colitis in rats. Our findings suggest that the microalga C. debaryana or derived oxylipins could be used as nutraceuticals in the treatment of the active phase of IBD.

  3. Cultivation factors and population size control the uptake of nitrogen by the microalgae Chlorella vulgaris when interacting with the microalgae growth-promoting bacterium Azospirillum brasilense.

    Science.gov (United States)

    de-Bashan, Luz E; Antoun, Hani; Bashan, Yoav

    2005-10-01

    Growth of and the capacity to take up nitrogen in the freshwater microalgae Chlorella vulgaris were studied while varying the concentrations of ammonium and nitrate, the pH and the source of carbon in a synthetic wastewater growth medium when co-immobilized in alginate beads with the microalgae growth-promoting bacterium Azospirillum brasilense. Analyses of 29 independent experiments showed that co-immobilization of the microalgae with A. brasilense could result in two independent phenomena directly affected by cultivation factors, such as nitrogen species, pH and presence of a carbon source. First, growth of the microalgal population increased without an increase in the capacity of the single cells to take up nitrogen, or second, the capacity of cells to take up nitrogen increased without an increase of the total microalgal population. These phenomena were dependent on the population density of the microalgae, which was in turn affected by cultivation factors. This supports the conclusion that the size of the microalgal population controls the uptake of nitrogen in C. vulgaris cells - the higher the population (regardless the experimental parameters), the less nitrogen each cell takes up.

  4. Atividade proteolítica e crescimento de matrinxã em natação sustentada e alimentado com dois níveis de proteína

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    Gustavo Alberto Arbeláez-Rojas

    2011-11-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da natação sustentada sobre a atividade digestiva proteolítica e o crescimento de juvenis de matrinxã (Brycon amazonicus, alimentados com dois níveis de proteína. Foram utilizados 240 peixes, tratados com 28 ou 38% de proteína bruta (PB, durante 60 dias, em duas situações distintas: em natação sustentada à velocidade de uma vez e meia o comprimento corporal por segundo, e em sistema convencional de cultivo, sem movimento forçado. Os peixes em natação sustentada e alimentados com 28% de PB apresentaram melhor desempenho, expresso como maior crescimento, alta taxa de crescimento específico, maior ganho de peso e melhor eficiência alimentar. A natação sustentada proporcionou aumento significativo da atividade digestiva proteolítica alcalina, proporcional ao conteúdo de proteína na dieta. Juvenis de matrinxã alimentados com dietas com 28% de PB e em natação sustentada apresentam melhor aproveitamento dos nutrientes como consequência de ação proteolítica digestiva mais efetiva.

  5. Educar con significado o con sentido

    Directory of Open Access Journals (Sweden)

    José Joaquín García García

    2017-01-01

    Full Text Available Hoy día, tres tendencias influyen directamente en la conformación de la escuela. En primer lugar, el afán de encontrar la esencia de todo encumbró a la razón e hizo de la racionalidad el único valor a defender en las aulas. En segundo lugar, el sistema capitalista hizo lo mismo con aquello que tiene valor de uso y valor de cambio, es decir, con la mercancía, validando solo lo que puede tener una utilidad económica conocida o posible. Esto convirtió a la educación en un proceso para certificar y ganar dinero, desdibujando así su intención de formar personas. Finalmente, la visión masculina y eurocéntrica con su locura por quererlo dominar todo, y de pensar que el hombre era el dueño del planeta e inclusive la vida y el destino de los otros hombres, mutiló culturas y eliminó a la naturaleza de los currículums en los centros educativos.

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

    Science.gov (United States)

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

    2017-03-27

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

  7. SUCESIÓN DE MICROALGAS PERIFÍTICAS EN TRIBUTARIOS DEL RÍO GAIRA, SIERRA NEVADA DE SANTA MARTA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Farid Jesús OSORIO ÁVILA

    2015-01-01

    Full Text Available Las microalgas poseen atributos para la bioindicación, el estudio de algas perifíticas en ecosistemas fluviales tropicales, es de vital importancia ya que permite interpretar la dinámica de estos ecosistemas con importancia ecológica y con vocación para ofrecer servicios de abastecimiento. Para este estudio se seleccionaron tributarios de la cuenca media del río Gaira (SNSM, se evaluó el proceso sucesional de microalgas perifíticas, siguiendo el avance de la comunidad desde enero hasta abril de 2012, mediante la metodología de sustratos artificiales. El propósito fue analizar la variación en la estructura de la comunidad, durante el proceso de sucesión y evaluar los factores ambientales que determinan esta variación en un rio tropical. Los resultados destacan caudal, luz y oxígeno disuelto los cuales presentaron los valores más altos para el tributario C (Jabalí; el pH fue ligeramente básico para todos los sitios, la temperatura y conductividad presentaron valores más altos en el tributario A (Honduras. Durante las primeras semanas de exposición del sustrato Melosira varians y Lyngbya sp. fueron dominantes para los tributarios A y B (La Picúa, mientras que para el tributario C lo fueron Fragilaria sp., Nitzschia sp. y Melosira varians. Después de la cuarta semana de colecta se registraron los mayores valores de diversidad y riqueza de especies. Fueron más notorios los cambios en densidad que en composición de especies, a pesar de esto el proceso de sucesión fue completo y se evidenció la presencia de especies pioneras (Lyngbya sp., Nitzschia sp., intermedias (Melosira varians, Cocconeis placentula y tardías (Surirella sp..

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

    Directory of Open Access Journals (Sweden)

    Farid Chemat

    2011-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Sarman Oktovianus Gultom

    2014-07-01

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

  10. Acclimation of microalgae to wastewater environments involves increased oxidative stress tolerance activity.

    Science.gov (United States)

    Osundeko, Olumayowa; Dean, Andrew P; Davies, Helena; Pittman, Jon K

    2014-10-01

    A wastewater environment can be particularly toxic to eukaryotic microalgae. Microalgae can adapt to these conditions but the specific mechanisms that allow strains to tolerate wastewater environments are unclear. Furthermore, it is unknown whether the ability to acclimate microalgae to tolerate wastewater is an innate or species-specific characteristic. Six different species of microalgae (Chlamydomonas debaryana, Chlorella luteoviridis, Chlorella vulgaris, Desmodesmus intermedius, Hindakia tetrachotoma and Parachlorella kessleri) that had never previously been exposed to wastewater conditions were acclimated over an 8-week period in secondary-treated municipal wastewater. With the exception of C. debaryana, acclimation to wastewater resulted in significantly higher growth rate and biomass productivity. With the exception of C. vulgaris, total chlorophyll content was significantly increased in all acclimated strains, while all acclimated strains showed significantly increased photosynthetic activity. The ability of strains to acclimate was species-specific, with two species, C. luteoviridis and P. kessleri, able to acclimate more efficiently to the stress than C. debaryana and D. intermedius. Metabolic fingerprinting of the acclimated and non-acclimated microalgae using Fourier transform infrared spectroscopy was able to differentiate strains on the basis of metabolic responses to the stress. In particular, strains exhibiting greater stress response and altered accumulation of lipids and carbohydrates could be distinguished. The acclimation to wastewater tolerance was correlated with higher accumulation of carotenoid pigments and increased ascorbate peroxidase activity.

  11. Chlorella protothecoides Microalgae as an Alternative Fuel for Tractor Diesel Engines

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    Saddam H. Al-lwayzy

    2013-02-01

    Full Text Available Biodiesel has attracted a great deal attention recently as an alternative fuel due to increasing fuel prices and the imperative to reduce emissions. Among a wide range of biodiesel resources, microalgae are a promising alternative fuel source because of the high biomass, lipid productivity and environmentally friendliness. Microalgae is also a non-edible food, therefore, there will be no impact on the human food supply chain. In this work, petroleum diesel (PD and biodiesel from the microalgae Chlorella protothecoides (MCP-B20 blend have been used to examine the performance and the emission of a 25.8 kW agriculture tractor engine. Two engine speeds at maximum power take off (PTO power and torque have been selected for analysis using analysis of variance (ANOVA. The results showed that there is no significant difference between the engine performance when microalgae biodiesel blend (MCP-B20 and PD were used. However, a significant reduction in CO, CO2 and NO emissions was found when MCP-B20 was used. These outcomes give strong indication that microalgae can be successfully used in tractors as alternative fuel.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Takashi Nakamura

    2003-04-01

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

  13. Membrane Proteomic Insights into the Physiology and Taxonomy of an Oleaginous Green Microalga.

    Science.gov (United States)

    Garibay-Hernández, Adriana; Barkla, Bronwyn J; Vera-Estrella, Rosario; Martinez, Alfredo; Pantoja, Omar

    2017-01-01

    Ettlia oleoabundans is a nonsequenced oleaginous green microalga. Despite the significant biotechnological interest in producing value-added compounds from the acyl lipids of this microalga, a basic understanding of the physiology and biochemistry of oleaginous microalgae is lacking, especially under nitrogen deprivation conditions known to trigger lipid accumulation. Using an RNA sequencing-based proteomics approach together with manual annotation, we are able to provide, to our knowledge, the first membrane proteome of an oleaginous microalga. This approach allowed the identification of novel proteins in E. oleoabundans, including two photoprotection-related proteins, Photosystem II Subunit S and Maintenance of Photosystem II under High Light1, which were considered exclusive to higher photosynthetic organisms, as well as Retinitis Pigmentosa Type 2-Clathrin Light Chain, a membrane protein with a novel domain architecture. Free-flow zonal electrophoresis of microalgal membranes coupled to liquid chromatography-tandem mass spectrometry proved to be a useful technique for determining the intracellular location of proteins of interest. Carbon-flow compartmentalization in E. oleoabundans was modeled using this information. Molecular phylogenetic analyses of protein markers and 18S ribosomal DNA support the reclassification of E. oleoabundans within the trebouxiophycean microalgae, rather than with the Chlorophyceae class, in which it is currently classified, indicating that it may not be closely related to the model green alga Chlamydomonas reinhardtii A detailed survey of biological processes taking place in the membranes of nitrogen-deprived E. oleoabundans, including lipid metabolism, provides insights into the basic biology of this nonmodel organism.

  14. A type 2 diacylglycerol acyltransferase accelerates the triacylglycerol biosynthesis in heterokont oleaginous microalga Nannochloropsis oceanica.

    Science.gov (United States)

    Li, Da-Wei; Cen, Shi-Ying; Liu, Yu-Hong; Balamurugan, Srinivasan; Zheng, Xin-Yan; Alimujiang, Adili; Yang, Wei-Dong; Liu, Jie-Sheng; Li, Hong-Ye

    2016-07-10

    Oleaginous microalgae have received a considerable attention as potential biofuel feedstock. However, lack of industry-suitable strain with lipid rich biomass limits its commercial applications. Targeted engineering of lipogenic pathways represents a promising strategy to enhance the efficacy of microalgal oil production. In this study, a type 2 diacylglycerol acyltransferase (DGAT), a rate-limiting enzyme in triacylglycerol (TAG) biosynthesis, was identified and overexpressed in heterokont oleaginous microalga Nannochloropsis oceanica for the first time. Overexpression of DGAT2 in Nannochloropsis increased the relative transcript abundance by 3.48-fold in engineered microalgae cells. TAG biosynthesis was subsequently accelerated by DGAT2 overexpression and neutral lipid content was significantly elevated by 69% in engineered microalgae. The fatty acid profile determined by GC-MS revealed that fatty acid composition was altered in engineered microalgae. Saturated fatty acids and polyunsaturated fatty acids were found to be increased whereas monounsaturated fatty acids content decreased. Furthermore, DGAT2 overexpression did not show negative impact on algal growth parameters. The present investigation showed that the identified DGAT2 would be a potential candidate for enhancing TAG biosynthesis and might facilitate the development of promising oleaginous strains with industrial potential.

  15. Direct Biodiesel Production from Wet Microalgae Biomass of Chlorella pyrenoidosa through In Situ Transesterification

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    Hechun Cao

    2013-01-01

    Full Text Available A one-step process was applied to directly converting wet oil-bearing microalgae biomass of Chlorella pyrenoidosa containing about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production.

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

    Directory of Open Access Journals (Sweden)

    Xin eZhang

    2014-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Dr. T. Nakamura

    2003-05-01

    Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 January to 31 March 2003 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work during the previous reporting period, PSI conducted preparation work on direct feeding of coal combustion gas to microalgae and developed a design concept for photobioreactors for biofixation of CO{sub 2} and photovoltaic power generation. Aquasearch continued their effort on characterization of microalgae suitable for CO{sub 2} sequestration and preparation for pilot scale demonstration. University of Hawaii continued effort on system optimization of the CO{sub 2} sequestration system.

  18. Metabolic Engineering of Eukaryotic Microalgae: Potential and Challenges come with great diversity

    Directory of Open Access Journals (Sweden)

    Javier A Gimpel

    2015-12-01

    Full Text Available The great phylogenetic diversity of microalgae is corresponded by a wide arrange of interesting and useful metabolites. Nonetheless metabolic engineering in microalgae has been limited, since specific transformation tools must be developed for each species for either the nuclear or chloroplast genomes. Microalgae as production platforms for metabolites offer several advantages over plants and other microorganisms, like the ability of GMO containment and reduced costs in culture media, respectively. Currently, microalgae have proved particularly well suited for the commercial production of omega-3 fatty acids and carotenoids. Therefore most metabolic engineering strategies have been developed for these metabolites. Microalgal biofuels have also drawn great attention recently, resulting in efforts for improving the production of hydrogen and photosynthates, particularly triacylglycerides. Metabolic pathways of microalgae have also been manipulated in order to improve photosynthetic growth under specific conditions and for achieving trophic conversion. Although these pathways are not strictly related to secondary metabolites, the synthetic biology approaches could potentially be translated to this field and will also be discussed.

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

    Directory of Open Access Journals (Sweden)

    David K Y Lim

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

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

    Science.gov (United States)

    Lim, David K Y; Garg, Sourabh; Timmins, Matthew; Zhang, Eugene S B; Thomas-Hall, Skye R; Schuhmann, Holger; Li, Yan; Schenk, Peer M

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

  2. In Metabolic Engineering of Eukaryotic Microalgae: Potential and Challenges Come with Great Diversity

    Science.gov (United States)

    Gimpel, Javier A.; Henríquez, Vitalia; Mayfield, Stephen P.

    2015-01-01

    The great phylogenetic diversity of microalgae is corresponded by a wide arrange of interesting and useful metabolites. Nonetheless metabolic engineering in microalgae has been limited, since specific transformation tools must be developed for each species for either the nuclear or chloroplast genomes. Microalgae as production platforms for metabolites offer several advantages over plants and other microorganisms, like the ability of GMO containment and reduced costs in culture media, respectively. Currently, microalgae have proved particularly well suited for the commercial production of omega-3 fatty acids and carotenoids. Therefore most metabolic engineering strategies have been developed for these metabolites. Microalgal biofuels have also drawn great attention recently, resulting in efforts for improving the production of hydrogen and photosynthates, particularly triacylglycerides. Metabolic pathways of microalgae have also been manipulated in order to improve photosynthetic growth under specific conditions and for achieving trophic conversion. Although these pathways are not strictly related to secondary metabolites, the synthetic biology approaches could potentially be translated to this field and will also be discussed. PMID:26696985

  3. Direct biodiesel production from wet microalgae biomass of Chlorella pyrenoidosa through in situ transesterification.

    Science.gov (United States)

    Cao, Hechun; Zhang, Zhiling; Wu, Xuwen; Miao, Xiaoling

    2013-01-01

    A one-step process was applied to directly converting wet oil-bearing microalgae biomass of Chlorella pyrenoidosa containing about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production.

  4. Nutritional evaluation of microalgae oils rich in omega-3 long chain polyunsaturated fatty acids as an alternative for fish oil.

    Science.gov (United States)

    Ryckebosch, Eline; Bruneel, Charlotte; Termote-Verhalle, Romina; Goiris, Koen; Muylaert, Koenraad; Foubert, Imogen

    2014-10-01

    The purpose of this work was to evaluate the nutritional value of the total lipid extract of different omega-3 long chain polyunsaturated fatty acids producing photoautotrophic microalgae in one study. It was shown that microalgae oils from Isochrysis, Nannochloropsis, Phaeodactylum, Pavlova and Thalassiosira contain sufficient omega-3 LC-PUFA to serve as an alternative for fish oil, which was used as the 'golden standard'. In the microalgae oils an important part of the omega-3 long chain polyunsaturated fatty acids are present in the polar lipid fraction, which may be favourable from a bioavailability and stability viewpoint. Consumption of microalgae oil ensures intake of sterols and carotenoids. The intake of sterols, including cholesterol and phytosterols, is probably not relevant. The intake of carotenoids is however definitely significant and could give the microalgae oils a nutritional added value compared to fish oil.

  5. Carbon dioxide capture and nutrients removal utilizing treated sewage by concentrated microalgae cultivation in a membrane photobioreactor.

    Science.gov (United States)

    Honda, Ryo; Boonnorat, Jarungwit; Chiemchaisri, Chart; Chiemchaisri, Wilai; Yamamoto, Kazuo

    2012-12-01

    A highly efficient microalgae cultivation process was developed for carbon dioxide capture using nutrients from treated sewage. A submerged-membrane filtration system was installed in a photobioreactor to achieve high nutrient loading and to maintain a high concentration and production of microalgae. Chlorella vulgaris, Botryococcus braunii and Spirulina platensis were continuously cultivated with simulated treated sewage and 1%-CO(2) gas. The optimum hydraulic retention time (HRT) and solids retention time (SRT) were explored to achieve the maximum CO(2) capture rate, nutrient removal rate and microalgae biomass productivity. The carbon dioxide capture rate and volumetric microalgae productivity were high when the reactor was operated under 1-day (HRT) and 18-days (SRT) conditions. The independent control of HRT and SRT is effective for efficient microalgae cultivation and carbon dioxide capture using treated sewage.

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

    Directory of Open Access Journals (Sweden)

    Helena Sovová

    2016-05-01

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

  7. Capacidade aeróbia de ratos alimentados com dieta rica em frutose Aerobic capacity of rats fed with fructose rich diet

    Directory of Open Access Journals (Sweden)

    Rodrigo Ferreira de Moura

    2008-10-01

    Full Text Available INTRODUÇÃO: Evidências apontam que a ingestão exacerbada de frutose pode desencadear distúrbios característicos da síndrome metabólica. OBJETIVOS: Analisar os efeitos da ingestão de dieta rica em frutose sobre aspectos metabólicos de ratos da linhagem Wistar. Adicionalmente, verificar a capacidade aeróbia através da identificação da máxima fase estável de lactato (MFEL. MÉTODOS: Dezesseis ratos foram separados em dois grupos de oito animais: a controle, alimentados com dieta balanceada, e b frutose, alimentados com dieta rica em frutose. Foram analisadas a tolerância à glicose (área sob a curva de glicose durante teste de tolerância à glicose, sensibilidade à insulina (taxa de remoção da glicose sérica após sobrecarga exógena de insulina, perfil lipídico sérico e concentração de lactato sanguíneo [lac]s durante exercício na intensidade da MFEL. RESULTADOS: Teste t não pareado (p INTRODUCTION: Evidence points that exacerbated ingestion of fructose may trigger disturbs characteristic of the metabolic syndrome. OBJECTIVES: To analyze the effects of a fructose rich diet on metabolic aspects of Wistar lineage rats. Additionally, to verify the aerobic capacity, through the identification of the maximal lactate steady state (MSSL. PROCEDURES: Sixteen rats were separated in two groups of eight animals: a Control, fed a balanced diet, and b fructose, fed a fructose-rich diet. The glucose tolerance, (area under serum glucose during a glucose tolerance test, insulin sensibility (glucose disappearance rate after exogenous insulin administration, serum lipid profile and blood lactate concentration [lac]b during exercise at MSSL intensity, have been analyzed. RESULTS: Non-paired t test (p<0.05 revealed difference between groups in the area under the curve of glucose and serum triglycerides, no difference in insulin sensibility or in [lac]b was detected, though. One-way ANOVA with Newman Keuls post hoc revealed difference in

  8. Design of a Novel Photobioreactor for Culture of Microalgae

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper presents the design of a novel photobioreactor for cultivation of microalgae. The body of the reactor with volume of about 40 L is parallelipipedic and divided in five compartments that can be put in series. The optical guides, plunged perpendicularly into the compartments, are upright Plexiglas plates on which side faces there are defined grooves that are able to diffuse light laterally and ensure an even distribution of light in the medium. External airlifts through the side columns are used for mixing of culture medium. The external light source is a SON-T lamp mounted inside a projector that provides a conical light dispersion, it is interchangeable and may take different positions. The design offers the photobioreactor characteristics including mainly interchangeable light source, homogenous distribution of light, perfect mixing of suspension of algae, high ratio of illuminating surface to volume of reactor, compactness and absence of contamination. Schemes, view of the photobioractor and data of continuous culture for Spirulina maxima are presented.

  9. Toxicity and Accumulation of Selenite in Four Microalgae

    Institute of Scientific and Technical Information of China (English)

    王大志; 程兆第; 李少菁; 高亚辉

    2003-01-01

    The toxicity and bioaccumlation of selenite in four microalgae, Spirulina platensis,Dunaliella salina, Dunaliella bardawill and Phaeodactylum tricornutum cultured in the presence of selenite were investigated. Lower concentrations of selenite were generally nontoxic and frequently stimulated algal growth, while higher concentrations of selenite inhibited algal growth. Selenite was more toxic to D. salina and D. bardawill than to S. platensis and P. tricornutum. All algae cultured in selenite were able to incorporate Se to different degrees, which depended on algal species. The distributions of selenite among intracellular macromolecular compounds were different among algal species: most of the selenite was associated with proteins in S. platensis, D. salina and D. bardawill, while most of the selenite was associated with lipids in P. tricornutum, which reflected the physiological differences among the algae. These observations suggest that algae are able to accumulate selenite and bind it with intracellular macromolecular compounds when exposed to high concentration of selenite. This may represent a form of storage or detoxification of selenite by the algae.

  10. Electromagnetic response of the protective pellicle of different unicellular microalgae

    Science.gov (United States)

    Inchaussandague, Marina E.; Skigin, Diana C.; Tolivia, Analía.; Fuertes Vila, Isabel; Conforti, Visitación

    2014-03-01

    Euglenoids are unicellular aquatic organisms. These microalgae show a typical surface structure that distinguishes them from the other protists. Most cells are naked and bounded by a plasma membrane surrounded by a pellicle formed by overlapping bands. It is well known that all terrestrial and aquatic organisms are exposed to UV-A and UV-B radiation. This radiation is potentially harmful to life and since it can penetrate up to 12 meters in the water, it can reduce survival, growth and production of phytoplankton. However, the organisms have developed numerous protection mechanisms intended to reduce such damage, such as the production of pigments and other repair mechanisms. However, the possible protection that could provide the first barriers before entering into the cell has not been explored yet. In this paper we investigate, from an electromagnetic point of view, the role played by the pellicle of euglenoids in the protection of the cell against UV radiation. To do so, we investigate the electromagnetic response of different species that exhibit different behaviors against the UV radiation. We solve the diffraction problem by using the Chandezon Method and obtain the reflectance of the pellicle for the UV wavelengths. The results show that the corrugated pellicle could contribute to increase the reflectance, thus reducing the penetration of the UV radiation within the cell and therefore, minimizing the damage and increasing the survival of these organisms.

  11. Bioactive Compounds Isolated from Microalgae in Chronic Inflammation and Cancer

    Directory of Open Access Journals (Sweden)

    Elena Talero

    2015-09-01

    Full Text Available The risk of onset of cancer is influenced by poorly controlled chronic inflammatory processes. Inflammatory diseases related to cancer development include inflammatory bowel disease, which can lead to colon cancer, or actinic keratosis, associated with chronic exposure to ultraviolet light, which can progress to squamous cell carcinoma. Chronic inflammatory states expose these patients to a number of signals with tumorigenic effects, including nuclear factor kappa B (NF-κB and mitogen-activated protein kinases (MAPK activation, pro-inflammatory cytokines and prostaglandins release and ROS production. In addition, the participation of inflammasomes, autophagy and sirtuins has been demonstrated in pathological processes such as inflammation and cancer. Chemoprevention consists in the use of drugs, vitamins, or nutritional supplements to reduce the risk of developing or having a recurrence of cancer. Numerous in vitro and animal studies have established the potential colon and skin cancer chemopreventive properties of substances from marine environment, including microalgae species and their products (carotenoids, fatty acids, glycolipids, polysaccharides and proteins. This review summarizes the main mechanisms of actions of these compounds in the chemoprevention of these cancers. These actions include suppression of cell proliferation, induction of apoptosis, stimulation of antimetastatic and antiangiogenic responses and increased antioxidant and anti-inflammatory activity.

  12. Removal and Biodegradation of Nonylphenol by Four Freshwater Microalgae

    Science.gov (United States)

    He, Ning; Sun, Xian; Zhong, Yu; Sun, Kaifeng; Liu, Weijie; Duan, Shunshan

    2016-01-01

    The removal and biodegradation of nonylphenol (NP) by four freshwater microalgae, including three green algae (Scendesmus quadriauda, Chlorella vulgaris, and Ankistrodesmus acicularis) and one cyanobacterium (Chroococcus minutus) were studied in bacteria-free cultures exposed to different concentrations of NP for 5 days. All four algal species showed a rapid and high ability to remove NP (including bioaccumulation and biodegradation). Among these species, A. acicularis (Ankistrodesmus acicularis) had the highest NP removal rate (83.77%) at 120 h when exposed to different NP treatments (0.5–2.5 mg·L−1), followed by C. vulgaris (Chlorella vulgaris) (80.80%), S. quadriauda (Scendesmus quadriauda) (70.96%) and C. minutus (Chroococcus minutus) (64.26%). C. vulgaris had the highest NP biodegradation percentage (68.80%) at 120 h, followed by A. acicularis (65.63%), S. quadriauda (63.10%); and C. minutus (34.91%). The extracellular NP contents were lower than the intracellular NP contents in all tested algae. The ratio of the extracellular NP content and the intracellular NP content ranged from 0.04 to 0.85. Therefore, the removal of NP from the medium was mainly due to the algal degradation. These results indicate that A. acicularis and C. vulgaris are more tolerant to NP and could be used for treatment of NP contaminated aqueous systems effectively by bioremoval and biodegradation. PMID:27983663

  13. Improving the feasibility of producing biofuels from microalgae using wastewater.

    Science.gov (United States)

    Rawat, I; Bhola, V; Kumar, R Ranjith; Bux, F

    2013-01-01

    Biofuels have received much attention recently owing to energy consumption and environmental concerns. Despite many of the technologies being technically feasible, the processes are often too costly to be commercially viable. The major stumbling block to full-scale production of algal biofuels is the cost of upstream and downstream processes and environmental impacts such as water footprint and indirect greenhouse gas emissions from chemical nutrient production. The technoeconomics of biofuels production from microalgae is currently unfeasible due to the cost of inputs and productivities achieved. The use of a biorefinery approach sees the production costs reduced greatly due to utilization of waste streams for cultivation and the generation of several potential energy sources and value-added products while offering environmental protection. The use of wastewater as a production media, coupled with CO2 sequestration from flue gas greatly reduces the microalgal cultivation costs. Conversion of residual biomass and by-products, such as glycerol, for fuel production using an integrated approach potentially holds the key to near future commercial implementation of biofuels production.

  14. Phototrophic pigment production with microalgae: biological constraints and opportunities.

    Science.gov (United States)

    Mulders, Kim J M; Lamers, Packo P; Martens, Dirk E; Wijffels, René H

    2014-04-01

    There is increasing interest in naturally produced colorants, and microalgae represent a bio-technologically interesting source due to their wide range of colored pigments, including chlorophylls (green), carotenoids (red, orange and yellow), and phycobiliproteins (red and blue). However, the concentration of these pigments, under optimal growth conditions, is often too low to make microalgal-based pigment production economically feasible. In some Chlorophyta (green algae), specific process conditions such as oversaturating light intensities or a high salt concentration induce the overproduction of secondary carotenoids (β-carotene in Dunaliella salina (Dunal) Teodoresco and astaxanthin in Haematococcus pluvialis (Flotow)). Overproduction of all other pigments (including lutein, fucoxanthin, and phycocyanin) requires modification in gene expression or enzyme activity, most likely combined with the creation of storage space outside of the photosystems. The success of such modification strategies depends on an adequate understanding of the metabolic pathways and the functional roles of all the pigments involved. In this review, the distribution of commercially interesting pigments across the most common microalgal groups, the roles of these pigments in vivo and their biosynthesis routes are reviewed, and constraints and opportunities for overproduction of both primary and secondary pigments are presented.

  15. Microalga Scenedesmus obliquus as a potential source for biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Shovon; Mallick, Nirupama [Indian Inst. of Technology, Kharagpur, West Bengal (India). Agricultural and Food Engineering Dept.

    2009-08-15

    Biodiesel from microalgae seems to be the only renewable biofuel that has the potential to completely replace the petroleum-derived transport fuels. Therefore, improving lipid content of microalgal strains could be a cost-effective second generation feedstock for biodiesel production. Lipid accumulation in Scenedesmus obliquus was studied under various culture conditions. The most significant increase in lipid reached 43% of dry cell weight (dcw), which was recorded under N-deficiency (against 12.7% under control condition). Under P-deficiency and thiosulphate supplementation the lipid content also increased up to 30% (dcw). Application of response surface methodology in combination with central composite rotary design (CCRD) resulted in a lipid yield of 61.3% (against 58.3% obtained experimentally) at 0.04, 0.03, and 1.0 g l{sup -1} of nitrate, phosphate, and sodium thiosulphate, respectively for time culture of 8 days. Scenedesmus cells pre-grown in glucose (1.5%)-supplemented N 11 medium when subjected to the above optimized condition, the lipid accumulation was boosted up to 2.16 g l{sup -1}, the value {proportional_to}40-fold higher with respect to the control condition. The presence of palmitate and oleate as the major constituents makes S. obliquus biomass a suitable feedstock for biodiesel production. (orig.)

  16. Microalgae respond differently to nitrogen availability during culturing

    Indian Academy of Sciences (India)

    Liliana G Gigova; Natalia J Ivanova

    2015-06-01

    Variations in the exogenous nitrogen level are known to significantly affect the physiological status and metabolism of microalgae. However, responses of red, green and yellow-green algae to nitrogen (N) availability have not been compared yet. Porphyridium cruentum, Scenedesmus incrassatulus and Trachydiscus minutus were cultured in the absence of N in the medium and subsequent resupply of N to the starved cells. Culture growth and in-gel changes in isoenzyme pattern and activity of glutamate synthase, glutamate dehydrogenase, malate dehydrogenase, aspartate aminotransferase, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase were studied. The results demonstrated that the algae responded to the fully N-depleted and N-replete culture conditions by species-specific metabolic enzyme changes, suggesting differential regulation of both enzyme activity and cellular metabolism. Substantial differences in the activities of the antioxidant enzymes between N-depleted and N-replete cells of each species as well as between the species were also found. In the present work, besides the more general responses, such as adjustment of growth and pigmentation, we report on the involvement of specific metabolic and antioxidant enzymes and their isoforms in the mechanisms operating during N starvation and recovery in P. cruentum, T. minutus and S. incrassatulus.

  17. Quantitative assessment of microalgae biomass and lipid stability post cultivation

    Directory of Open Access Journals (Sweden)

    Katerine eNapan

    2015-04-01

    Full Text Available Processing of microalgal biomass to biofuels and other products requires the removal of the culture from a well-controlled growth system to a containment or preprocessing step at non-ideal growth conditions, such as darkness, minimal gas exchange, and fluctuating temperatures. The conditions and the length of time between harvest and processing will impact microalgal metabolism resulting in biomass and lipid degradation. This study experimentally investigates the impact of time and temperature on Nannochloropsis salina harvested from outdoor plate photobioreactors. The impact of three temperatures, 4°, 40° or 70°C, on biomass and lipid content (as fatty acid methyl esters of the harvested microalgae was evaluated over a 156 hour time period. Results show that for N. salina, time and temperature are key factors that negatively impact biomass and lipid yields. The temperature of 70°C resulted in the highest degradation with the overall biofuel potential reduced by 30% over 156 hours. Short time periods, 24 hours, and low temperatures are shown to have little effect on the harvested biomass.

  18. Superior biolubricant from a species of red microalga.

    Science.gov (United States)

    Arad, Shoshana Malis; Rapoport, Lev; Moshkovich, Alex; van Moppes, Dorit; Karpasas, Mark; Golan, Roxana; Golan, Yuval

    2006-08-15

    The rheological properties of the sulfated polysaccharide of the red microalga Porphyridium sp., a heteropolymer with a molecular weight of 3-5 x 10(6) Da, indicated that this material might be an excellent candidate for lubrication applications: the viscosity of the polysaccharide is stable over a range of temperatures, pH values, and salinities. In this study, various rheological and lubricant properties of the polysaccharide were evaluated in comparison with those of a widely used biolubricant, hyaluronic acid. The viscosity of the Porphyridium sp. polysaccharide remained essentially unchanged in a temperature range of 25-70 degrees C. In tribology tests on a ball-on-flat ceramic pair, the values for the friction coefficient and wear rate for the pair lubricated with polysaccharide were remarkably lower than those for hyaluronic acid, especially at high loads. In a test on a steel ring/ultrahigh-molecular-weight polyethylene (UHMWPE) block pair, the wear tracks on the surface of the UHMWPE were more pronounced for hyaluronic acid than for the polysaccharide. Atomic force microscopy showed that the polysaccharide was effectively adsorbed onto mica surfaces, forming ultrathin coating layers in the nanometer range. As is required for biolubricant applications, the polysaccharide was not degraded by hyaluronidase. The stability of the Porphyridium sp. polysaccharide to heat and to hyaluronidase combined with its ability to reduce friction and wear indicate its potential as an advantageous biolubricant.

  19. Assessment of photosynthesis regulation in mixotrophically cultured microalga Chlorella sorokiniana

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tingting; Kirchhoff, Helmut; Gargouri, Mahmoud; Feng, Jie; Cousins, Asaph B.; Pienkos, Philip T.; Gang, David R.; Chen, Shulin

    2016-11-01

    Mixotrophic growth of microalgae offers great potential as an efficient strategy for biofuel production. In this study, photosynthetic regulation of mixotrophically cultured Chlorella sorokiniana cells was systematically evaluated. Mixotrophic cells in the exponential growth phase showed the highest photosynthetic activity, where maximum photosynthetic O2 evolution was approximately 3- and 4-fold higher than cells in the same phase grown photoautotrophically in 1% CO2 (in air) and air, respectively. Additionally, characteristic chlorophyll fluorescence parameters demonstrated that no limitation in electron transport downstream of PSII was detected in mixotrophic cells. Up-regulation of photosynthetic activity was associated with high total ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylase activity and expression level of phosphoribulokinase (PRK). After 3 days, photosynthetic O2 evolution of mixotrophic cells that went to the stationary phase, was strongly reduced, with reduced photochemical efficiency and reorganization of the PSII complex. Simultaneously, enzymatic activity for Rubisco carboxylase and mRNA levels of Rubisco and PRK diminished. Importantly, there was almost no non-photochemical quenching for mixotrophic cells, whether grown in log or stationary phase. A decline in the quantum efficiency of PSII and an oxidized plastoquinone pool (PQ pool) was observed under N-depleted conditions during mixotrophic growth. These results demonstrate that photosynthesis is regulated differently in mixotrophically cultured C. sorokiniana cells than in cells grown under photoautotrophic conditions, with a particularly strong impact by nitrogen levels in the cells.

  20. Slab waveguide photobioreactors for microalgae based biofuel production.

    Science.gov (United States)

    Jung, Erica Eunjung; Kalontarov, Michael; Doud, Devin F R; Ooms, Matthew D; Angenent, Largus T; Sinton, David; Erickson, David

    2012-10-07

    Microalgae are a promising feedstock for sustainable biofuel production. At present, however, there are a number of challenges that limit the economic viability of the process. Two of the major challenges are the non-uniform distribution of light in photobioreactors and the inefficiencies associated with traditional biomass processing. To address the latter limitation, a number of studies have demonstrated organisms that directly secrete fuels without requiring organism harvesting. In this paper, we demonstrate a novel optofluidic photobioreactor that can help address the light distribution challenge while being compatible with these chemical secreting organisms. Our approach is based on light delivery to surface bound photosynthetic organisms through the evanescent field of an optically excited slab waveguide. In addition to characterizing organism growth-rates in the system, we also show here, for the first time, that the photon usage efficiency of evanescent field illumination is comparable to the direct illumination used in traditional photobioreactors. We also show that the stackable nature of the slab waveguide approach could yield a 12-fold improvement in the volumetric productivity.

  1. Optimization of protein electroextraction from microalgae by a flow process.

    Science.gov (United States)

    Coustets, Mathilde; Joubert-Durigneux, Vanessa; Hérault, Josiane; Schoefs, Benoît; Blanckaert, Vincent; Garnier, Jean-Pierre; Teissié, Justin

    2015-06-01

    Classical methods, used for large scale treatments such as mechanical or chemical extractions, affect the integrity of extracted cytosolic protein by releasing proteases contained in vacuoles. Our previous experiments on flow processes electroextraction on yeasts proved that pulsed electric field technology allows preserving the integrity of released cytosolic proteins, by not affecting vacuole membranes. Furthermore, large cell culture volumes are easily treated by the flow technology. Based on this previous knowledge, we developed a new protocol in order to electro-extract total cytoplasmic proteins from microalgae (Nannochloropsis salina, Chlorella vulgaris and Haematococcus pluvialis). Given that induction of electropermeabilization is under the control of target cell size, as the mean diameter for N. salina is only 2.5 μm, we used repetitive 2 ms long pulses of alternating polarities with stronger field strengths than previously described for yeasts. The electric treatment was followed by a 24h incubation period in a salty buffer. The amount of total protein release was observed by a classical Bradford assay. A more accurate evaluation of protein release was obtained by SDS-PAGE. Similar results were obtained with C. vulgaris and H. pluvialis under milder electrical conditions as expected from their larger size.

  2. Fuel Property of Biodiesel Made from Microalgae (Chlorella Sp.

    Directory of Open Access Journals (Sweden)

    S. V. Kelaiya,

    2015-12-01

    Full Text Available Microalgae chlorella is an organism capable of photosynthesis that is less than 2mm in diameter. The biodiesel extracted from algae using chloroform/methanol extraction solvent system then undergone three different transesterification processes based on three different catalysts viz. Alkali catalyst, Acid catalyst and Enzymatic catalyst with two temperature (50°C and 60 °C and with 1:5 methanol to bio-oil ratio. After transesterification using different catalysts, the fuel properties were measured. All the properties were compared with standard value of ASTM D 6751 standards. Alkali catalyst yield highest biodiesel (92 % at 60 °C temperature. Also, the closest value of different fuel properties found at par with standard value of ASTM D 6751 standards viz. moisture content, carbon residue, calorific value, specific gravity, acid value, flash point, viscosity, density, viscosity were found to be 0.01%, 0.04%, 40.41 MJ/kg, 0.83, 0.23 mg KOH/g, 143.67 °C, 5.16 mm2/s, 0.83 g/cm3 respectively in the biodiesel which was yield by transesterification done using Alkali catalyst (0.56 % NaOH at 60 °C temperature.

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

    Directory of Open Access Journals (Sweden)

    Claude Durrieu

    2012-12-01

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

  4. Ultrasound assisted extraction of carbohydrates from microalgae as feedstock for yeast fermentation.

    Science.gov (United States)

    Zhao, Guili; Chen, Xue; Wang, Lei; Zhou, Shixiao; Feng, Huixing; Chen, Wei Ning; Lau, Raymond

    2013-01-01

    Recently, carbohydrates biomass from microalgae is considered as a promising and inexpensive feedstock for biofeuls production by microorganism fermentation. The main obstacle of the process is microalgae pretreatment and carbohydrates extraction from algal cell. In this study, comparison of three pretreatment methods was performed and the results showed that ultrasonic assisted extraction (UAE) was very effective. The effects of four parameters (ultrasonic power, extraction time, flow rate and algal cell concentration, respectively) on extraction efficiency were also investigated. Additionally, in order to identify significant factors for glucose yield, combination of these four parameters was examined by using fractional factorial design (FFD) and the regression model was obtained. Meanwhile, the refined model was confirmed as a good fitting model via analysis of variance (ANOVA). After extraction, glucose obtained from microalgae was used as substrate for Rhodosporidium toruloides fermentation and yeast biomass was much higher than that of control culture.

  5. Selection and adaptation of microalgae to growth in 100% unfiltered coal-fired flue gas.

    Science.gov (United States)

    Aslam, Ambreen; Thomas-Hall, Skye R; Mughal, Tahira Aziz; Schenk, Peer M

    2017-03-01

    Microalgae have been considered for biological carbon capture and sequestration to offset carbon emissions from fossil fuel combustion. This study shows that mixed biodiverse microalgal communities can be selected for and adapted to tolerate growth in 100% flue gas from an unfiltered coal-fired power plant that contained 11% CO2. The high SOx and NOx emissions required slow adaptation of microalgae over many months, with step-wise increases from 10% to 100% flue gas supplementation and phosphate buffering at higher concentrations. After a rapid decline in biodiversity over the first few months, community profiling revealed Desmodesmus spp. as the dominant microalgae. To the authors' knowledge this work is the first to demonstrate that up 100% unfiltered flue gas from coal-fired power generation can be used for algae cultivation. Implementation of serial passages over a range of photobioreactors may contribute towards the development of microalgal-mediated carbon capture and sequestration processes.

  6. LIPID PRODUCING MICROALGAE FROM SEVERAL ECOSYSTEMS IN WEST AND CENTRAL JAVA, INDONESIA

    Directory of Open Access Journals (Sweden)

    DWI ANDREAS SANTOSA

    2010-07-01

    Full Text Available This study is aimed to get lipid producing microalgae as feedstock for biofuel production. The microalgae were isolated from 355 collected water samples which represented many distinct ecosystems such as paddy fields, rivers, agricultural dams, ponds, swampy areas and unique ecosystem of volcano and mud-volcano craters in West- and Central Java, Indonesia. A total of 267 strains of microalgae were isolated from the samples of which 221 strains of them have capability to produce lipid. There were four promising strains that produce lipid between 14.7 – 45.7 percent dry weight in optimal condition that were identified as Chlamydomonas sp. KO-7267 and PK-7195, Chlorella sp. KS-7300 and Desmodesmus sp. BK-7291.

  7. TOR (target of rapamycin) is a key regulator of triacylglycerol accumulation in microalgae.

    Science.gov (United States)

    Imamura, Sousuke; Kawase, Yasuko; Kobayashi, Ikki; Shimojima, Mie; Ohta, Hiroyuki; Tanaka, Kan

    2016-01-01

    Most microalgae abundantly accumulate lipid droplets (LDs) containing triacylglycerols (TAGs) under several stress conditions, but the underlying molecular mechanism of this accumulation remains unclear. In a recent study, we found that inhibition of TOR (target of rapamycin), a highly conserved protein kinase of eukaryotes, by rapamycin resulted in TAG accumulation in microalgae, indicating that TOR negatively regulates TAG accumulation. Here, we show that formation of intracellular LDs and TAG accumulation were also induced in the unicellular green alga Chlamydomonas reinhardtii after exposure to Torin1 or AZD8055, which are novel TOR inhibitors that inhibit TOR activity in a manner different from rapamycin. These results supported quite well our previous conclusion that TOR is a central regulator of TAG accumulation in microalgae.

  8. Regulation of starch and lipid accumulation in a microalga Chlorella sorokiniana.

    Science.gov (United States)

    Li, Tingting; Gargouri, Mahmoud; Feng, Jie; Park, Jeong-Jin; Gao, Difeng; Miao, Chao; Dong, Tao; Gang, David R; Chen, Shulin

    2015-03-01

    Microalgae have attracted growing attention due to their potential in biofuel feedstock production. However, current understanding of the regulatory mechanisms for lipid biosynthesis and storage in microalgae is still limited. This study revealed that the microalga Chlorella sorokiniana showed sequential accumulation of starch and lipids. When nitrogen was replete and/or depleted over a short period, starch was the predominant carbon storage form with basal levels of lipid accumulation. After prolonged nitrogen depletion, lipid accumulation increased considerably, which was partially due to starch degradation, as well as the turnover of primary metabolites. Lipid accumulation is also strongly dependent on the linear electron flow of photosynthesis, peaking at lower light intensities. Collectively, this study reveals a relatively clear regulation pattern of starch and lipid accumulation that is basically controlled by nitrogen levels. The mixotrophic growth of C. sorokiniana shows promise for biofuel production in terms of lipid accumulation in the final biomass.

  9. Gene Discovery for Synthetic Biology: Exploring the Novel Natural Product Biosynthetic Capacity of Eukaryotic Microalgae.

    Science.gov (United States)

    O'Neill, E C; Saalbach, G; Field, R A

    2016-01-01

    Eukaryotic microalgae are an incredibly diverse group of organisms whose sole unifying feature is their ability to photosynthesize. They are known for producing a range of potent toxins, which can build up during harmful algal blooms causing damage to ecosystems and fisheries. Genome sequencing is lagging behind in these organisms because of their genetic complexity, but transcriptome sequencing is beginning to make up for this deficit. As more sequence data becomes available, it is apparent that eukaryotic microalgae possess a range of complex natural product biosynthesis capabilities. Some of the genes concerned are responsible for the biosynthesis of known toxins, but there are many more for which we do not know the products. Bioinformatic and analytical techniques have been developed for natural product discovery in bacteria and these approaches can be used to extract information about the products synthesized by algae. Recent analyses suggest that eukaryotic microalgae produce many complex natural products that remain to be discovered.

  10. Screening for lipid yielding microalgae: activities for 1983. Final subcontract report

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, W. H.; Tornabene, T. G.; Weissman, J.

    1984-04-01

    The SERI/DOE Aquatic Species Program is conducting a screening project, to select microalgae species and strains that are acceptable for liquid fuel production in outdoor culture. The emphases are on finding species that grow rapidly at high biomass density, in outdoor culture and produce large quantities of lipids. During 1983 over 100 species were isolated from saline waters at the California and Nevada deserts. Some of these species were characterized for growth response to various nutrients, temperatures, and salinities. Selected species were analyzed for lipid composition. Lipids were characterized into fractions, hydrocarbons, isoprenoids, triglyceride, glycolipids, and phospholipids. The most promising species were tested for growth and monoculture sustainability in outdoor culture. Each section (microalgae selection, chemical profiles of microalgae, mass culture of macroalgae) was abstracted separately. 51 references, 8 figures, 14 tables.

  11. Microalgae-based biodiesel: economic analysis of downstream process realistic scenarios.

    Science.gov (United States)

    Ríos, Sergio D; Torres, Carmen M; Torras, Carles; Salvadó, Joan; Mateo-Sanz, Josep M; Jiménez, Laureano

    2013-05-01

    Microalgae oil has been identified as a reliable resource for biodiesel production due to its high lipid productivity and potential cultivation in non-fertile locations. However, high scale production of microalgae based biodiesel depends on the optimization of the entire process to be economically feasible. The selected strain, medium, harvesting methods, etc., sorely affects the ash content in the dry biomass which have a direct effect in the lipid content. Moreover, the suitable lipids for biodiesel production, some of the neutral/saponifiable, are only a fraction of the total ones (around 30% dry base biomass in the best case). The present work uses computational tools for the modeling of different scenarios of the harvesting, oil extraction and transesterification. This rigorous modeling approach detects process bottlenecks that could have led to an overestimation of the potentiality of the microalgae lipids as a resource for the biodiesel production.

  12. Assessing microalgae biorefinery routes for the production of biofuels via hydrothermal liquefaction.

    Science.gov (United States)

    López Barreiro, Diego; Samorì, Chiara; Terranella, Giuseppe; Hornung, Ursel; Kruse, Andrea; Prins, Wolter

    2014-12-01

    The interest in third generation biofuels from microalgae has been rising during the past years. Meanwhile, it seems not economically feasible to grow algae just for biofuels. Co-products with a higher value should be produced by extracting a particular algae fraction to improve the economics of an algae biorefinery. The present study aims at analyzing the influence of two main microalgae components (lipids and proteins) on the composition and quantity of biocrude oil obtained via hydrothermal liquefaction of two strains (Nannochloropsis gaditana and Scenedesmus almeriensis). The algae were liquefied as raw biomass, after extracting lipids and after extracting proteins in microautoclave experiments at different temperatures (300-375°C) for 5 and 15min. The results indicate that extracting the proteins from the microalgae prior to HTL may be interesting to improve the economics of the process while at the same time reducing the nitrogen content of the biocrude oil.

  13. Carotenoids from Marine Microalgae: A Valuable Natural Source for the Prevention of Chronic Diseases

    Directory of Open Access Journals (Sweden)

    Maria Filomena de Jesus Raposo

    2015-08-01

    Full Text Available Epidemiological studies have shown a relation between antioxidants and the prevention of several chronic diseases. Microalgae are a potential novel source of bioactive molecules, including a wide range of different carotenoids that can be used as nutraceuticals, food supplements and novel food products. The objective of this review is (i to update the research that has been carried out on the most known carotenoids produced by marine microalgae, including reporting on their high potentialities to produce other less known important compounds; (ii to compile the work that has been done in order to establish some relationship between carotenoids and oxidative protection and treatment; (iii to summarize the association of oxidative stress and the various reactive species including free radicals with several human diseases; and (iv to provide evidence of the potential of carotenoids from marine microalgae to be used as therapeutics to treat or prevent these oxidative stress-related diseases.

  14. Characterization of growth and lipid production by Chlorella sp. PCH90, a microalga native to Quebec.

    Science.gov (United States)

    Abdelaziz, Ahmed Elsayed Mohamed; Ghosh, Dipankar; Hallenbeck, Patrick C

    2014-03-01

    Microalgae are being investigated as potential candidates for biodiesel production since they can be grown without competition with food production, have an inherently fast growth rate, and can have a high lipid content under different nutrient limiting conditions. However, large scale production will best be carried out with indigenous strains, well adapted to local conditions. This study reports on the characterization of the novel microalga Chlorella sp. PCH90, isolated in Quebec. Its molecular phylogeny was established and lipid production studies as a function of the initial concentrations of nitrate, phosphate, and sodium chloride were carried out using response surface methodology. Under the appropriate conditions this microalga could produce up to 36% lipid and grew well in both synthetic medium and secondary effluent from a wastewater treatment plant at both 22 and 10°C. Thus, this strain is promising for further development as a potential biofuels producer under local climatic conditions.

  15. Antibacterial Activity of Freshwater Microalga Scenedesmus sp. on Foodborne Pathogens Staphylococcus aureus and Salmonella sp.

    Directory of Open Access Journals (Sweden)

    Aisha Gogoba Ishaq

    2016-01-01

    Full Text Available Microalgae possess promising bioactive compounds with a wide range of activities. In this study, crude pigment extract of Scenedesmus sp. a freshwater microalga was screened against two known foodborne pathogens Staphylococcus aureus (ATCC 25923 and Salmonella sp. (ATCC 14028 to evaluate its antimicrobial properties. The crude pigment of the microalga was extracted with 90 % acetone whereas antibacterial screening was done by agar well diffusion method. In addition, the MIC of crude pigment was determined following the macrobroth dilution method. Concentrations ranging from 0.35mg/ml – 3.48 mg/ml demonstrated highest inhibitory activity against Staphylococcus aureus (ATCC 25923.  The MIC was achieved at 0.08 mg/ ml. On the other hand, there was no inhibitory activity at any concentration of crude extract against Salmonella sp. (ATCC 14028.  Results of this study suggest that the inhibitory activity may be limited to gram positive foodborne pathogen Staphylococcus aureus.

  16. Co-cultivation of microalgae and nitrifiers for higher biomass production and better carbon capture.

    Science.gov (United States)

    Bilanovic, Dragoljub; Holland, Mark; Starosvetsky, Jeanna; Armon, Robert

    2016-11-01

    The aim of this work was to study co-cultivation of nitrifiers with microalgae as a non-intrusive technique for selective removal of oxygen generated by microalgae. Biomass concentration was, at least, 23% higher in mixed-cultures where nitrifiers kept the dissolved oxygen concentration below 9.0μLL(-1) than in control Chlorella vulgaris axenic-cultures where the concentration of dissolved oxygen was higher than 10.0μLL(-1). This approach to eliminating oxygen inhibition of microalgal growth could become the basis for the development of advanced microalgae reactors for removal of CO2 from the atmosphere, and concentrated CO2 streams. CO2 sequestration would become a chemically and geologically safer and environmentally more sound technology provided it uses microalgal, or other biomass, instead of CO2, for carbon storage.

  17. Synthesis of Optimal Processing Pathway for Microalgae-based Biorefinery under Uncertainty

    DEFF Research Database (Denmark)

    2015-01-01

    The research in the field of microalgae-based biofuels and chemicals is in early phase of the development, and therefore a wide range of uncertainties exist due to inconsistencies among and shortage of technical information. In order to handle and address these uncertainties to ensure robust...... decision making, we propose a systematic framework for the synthesis and optimal design of microalgae-based processing network under uncertainty. By incorporating major uncertainties into the biorefinery superstructure model we developed previously, a stochastic mixed integer nonlinear programming (s...... of uncertain parameters. The developed framework is implemented and tested on a specific case study, to identify the promising processing pathway for the production of biofuels from microalgae while accounting for modelled uncertainties....

  18. Heavy metal removal from acid mine drainage by calcined eggshell and microalgae hybrid system.

    Science.gov (United States)

    Choi, Hee-Jeong; Lee, Seung-Mok

    2015-09-01

    This study investigates the use of calcined eggshells and microalgae for the removal of heavy metals from acid mine drainage (AMD) and the simultaneous enhancement of biomass productivity. The experiment was conducted over a period of 6 days in a hybrid system containing calcined eggshells and the microalgae Chlorella vulgaris. The results show that the biomass productivity increased to ~8.04 times its initial concentration of 0.367 g/L as measured by an optical panel photobioreactor (OPPBR) and had a light transmittance of 95 % at a depth of 305 mm. On the other hand, the simultaneous percent removal of Fe, Cu, Zn, Mn, As, and Cd from the AMD effluent was found to be 99.47 to 100 %. These results indicate that the hybrid system with calcined eggshells and microalgae was highly effective for heavy metal removal in the AMD.

  19. Characterization and optimization of carbohydrate production from an indigenous microalga Chlorella vulgaris FSP-E.

    Science.gov (United States)

    Ho, Shih-Hsin; Huang, Shu-Wen; Chen, Chun-Yen; Hasunuma, Tomohisa; Kondo, Akihiko; Chang, Jo-Shu

    2013-05-01

    In this study, three indigenous microalgae isolates were examined for their ability to produce carbohydrates. Among them, Chlorella vulgaris FSP-E displayed relatively high cell growth rate and carbohydrate content. The carbohydrate productivity of C. vulgaris FSP-E was further improved by using engineering strategies. The results show that using an appropriate light intensity and inoculum size could effectively promote cell growth and carbohydrate productivity. Nitrogen starvation triggered the accumulation of carbohydrates in the microalga, achieving a carbohydrate content of 51.3% after 4-day starvation. Under the optimal conditions, the highest biomass and carbohydrate productivity were 1.437 and 0.631 g L(-1) d(-1), respectively. This performance is better than that reported in most related studies. Since glucose accounted for nearly 93% of the carbohydrates accumulated in C. vulgaris FSP-E, the microalga is an excellent feedstock for bioethanol fermentation.

  20. Nitrogen and phosphorus removal coupled with carbohydrate production by five microalgae cultures cultivated in biogas slurry.

    Science.gov (United States)

    Tan, Fen; Wang, Zhi; Zhouyang, Siyu; Li, Heng; Xie, Youping; Wang, Yuanpeng; Zheng, Yanmei; Li, Qingbiao

    2016-12-01

    In this study, five microalgae strains were cultured for their ability to survive in biogas slurry, remove nitrogen resources and accumulate carbohydrates. It was proved that five microalgae strains adapted in biogas slurry well without ammonia inhibition. Among them, Chlorella vulgaris ESP-6 showed the best performance on carbohydrate accumulation, giving the highest carbohydrate content of 61.5% in biogas slurry and the highest ammonia removal efficiency and rate of 96.3% and 91.7mg/L/d respectively in biogas slurry with phosphorus and magnesium added. Additionally, the absence of phosphorus and magnesium that can be adverse for biomass accumulation resulted in earlier timing of carbohydrate accumulation and magnesium was firstly recognized and proved as the influence factor for carbohydrate accumulation. Microalgae that cultured in biogas slurry accumulated more carbohydrate in cell, making biogas slurry more suitable medium for the improvement of carbohydrate content, thus can be regarded as a new strategy to accumulate carbohydrate.