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Sample records for cadmio sobre microalgas

  1. EFECTO DEL pH EN LA ADSORCIÓN DE CADMIO, NÍQUEL Y ZINC SOBRE UNA BENTONITA

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    Liz Adriana Pinilla Cuesta

    2010-11-01

    Full Text Available Se estudió el efecto del pH sobre la adsorción de cadmio, niquel y zinc, en solución acuosa a 25"C, sobre una bentonita colombiana proveniente del Valle del Cauca. Los datos experimentales se analizaron con base en las isotermas de adsorción, la constante termodinámica de reparto Kdm (calculada mediante la isoterma de Langmuir, la relación de distribución Rd (obtenida del modelo Baeyens-Bradbury y una gráfica Kurbatov. La adsorción de cadmio, niquel y zinc aumenta con el pH. El orden de adsorción encontrado: Cd > Ni≅Zn coincide con el establecido por el principio HSAB.

  2. Efecto del pH en la adsorción de cadmio, niquel y zinc sobre una bentonita

    Directory of Open Access Journals (Sweden)

    Liz Adriana Pinilla Cuenca

    2010-09-01

    Full Text Available Se estudió el efecto del pH sobre la adsorción de cadmio, niquel y zinc, en solución acuosa a 25°C, sobre una bentonita colombiana proveniente del Valle del Cauca. Los datos experimentales se analizaron con base en las isotermas de adsorción, la constante termodinámica de reparto KDM (calculada mediante la isoterma de Langmuir, la relación de distribución Rd (obtenida del modelo Baeyens-Bradbury y una gráfica Kurbatov.

  3. Aplicación de la isoterma langmuir a la adsorción competitiva de cadmio, níquel y zinc sobre una bentonita

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    Germán Darío Silva Giraldo; Jorge Alejo Pinzón Bello

    2010-01-01

    Se estudió la adsorción simultánea de los iones cadmio, níquel y zinc en solución acuosa de sus mezclas binarias y ternaria a 25°C, sobre una bentonita del Valle del Cauca, tanto en su estado natural como en su forma homoiónica de sodio.

  4. Estudio de la adsorción de cadmio, níquel y zinc sobre una bentonita natural y homoiónica de sodio

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    Germán Darío Silva Giraldo

    2010-09-01

    Full Text Available Se esmdió la adsorción de cadmio, níquel y zinc, en solución acuosa a 25 "C, sobre una bentonita procedente del Valle del Cauca, tanto en su estado natural como en su forma homoiónica de sodio.

  5. Efecto del cobre y del cadmio sobre la respuesta inmune innata del pez Colossoma macropomum

    OpenAIRE

    Vargas, A.; Blanco, Y.; Salazar-Lugo, R.

    2012-01-01

    En este trabajo se evaluó la respuesta inmunológica celular inespecífica del pez Colossoma macropomum (Cuvier, 1818) expuesto a concentraciones subletales de cobre y cadmio, a través de la determinación de la viabilidad celular, la quimiotaxis, la fagocitosis y la muerte bacteriana en células inmunocompetentes extraídas del riñón cefálico, la sangre y el hígado. Los peces fueron expuestos por separado a 0,5 mg/L de cloruro de cobre y 1,0 mg/L de cloruro de cadmio durante 28 días; después de l...

  6. Efecto de la fertilización fosforada sobre el contenido de cadmio en cuatro suelos de Chile

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    Bonomelli Claudia

    2003-01-01

    Full Text Available Los fertilizantes fosforados pueden contener cadmio (Cd y al utilizarlos pueden entrar en las cadenas tróficas. El objetivo de este estudio fue evaluar el efecto de la fertilización fosforada sobre la concentración de Cd disponible en cuatro tipos de suelos de Chile, que pertenecían a los ordenes Inceptisol, Alfisol, Ultisol y Andisol. Los dos tratamientos usados fueron el testigo sin fertilización y la aplicación de una dosis de corrección con un fertilizante comercial, superfosfato triple (SFT, que tenía una concentración de 53,2 mg de Cd por kg de fertilizante. La dosis de fertilizante aplicada fue la necesaria para alcanzar un nivel de 30 mg kg-1 de POlsen. Los suelos se incubaron en estufa durante 90 días, a 25masculineC y humedad de capacidad de campo. El diseño experimental fue completamente al azar, con tres repeticiones para cada suelo y donde la unidad experimental fue un contenedor con 250 g de suelo seco. Se midió Cd disponible a los 1, 2, 7, 14, 21, 36, 49, 63, 77 y 90 días después de la incubación. La aplicación de P en dosis agronómica, utilizando fertilizante con alto contenido de Cd, tuvo un efecto estadísticamente significativo sobre la concentración de Cd disponible en los suelos estudiados, sin embargo, no hubo efecto del tiempo de incubación en la disponibilidad de Cadmio.

  7. Adsorción de plomo y cadmio en sistema continuo de lecho fijo sobre residuos de cacao

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    Jose Lara

    2016-12-01

    Full Text Available Se evaluó el desempeño de la cáscara de cacao como material residual adsorbente de metales pesados (Plomo y Cadmio en solución acuosa sintética, mediante un sistema continuo de lecho fijo. El trabajo experimental consistió en determinar el efecto de la altura del lecho en la remoción de estos contaminantes, manteniendo constantes parámetros como el pH, velocidad de flujo y concentración inicial de los metales. Las pruebas de adsorción presentaron una remoción de 91,32 y 87,80% respectivamente para Pb y Cd después de transcurridos 4,5 h La medición de las concentraciones en solución acuosa de los iones metálicos se hizo por adsorción atómica. Se evaluó el ajuste de los modelos matemáticos de Thomas, Dosis-Respuesta, Adams-Bohart y BDST (Bed-Depht Service Time analysis, para predecir el comportamiento dinámico de la columna y obtener los parámetros cinéticos correspondientes. Para los modelos de Thomas y de Dosis-Respuesta, se observó que los valores de la capacidad inicial de adsorción, q0, disminuyeron al aumentar la altura del lecho, esto pudo deberse a una transferencia de masa más lenta, concentración más baja y aumento dela capacidad de adsorción, mientras que los modelos de Adams-Bohart y BDST, la capacidad de adsorción volumétrica, N0, decrece al aumentar el bioadsorbente en la columna. Los resultados presentados en este estudio indican que los residuos de cacao pueden ser usados para la remoción de metales pesados presentes en aguas residuales satisfactoriamente.

  8. Toxicidad del cadmio en plantas

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    Rodríguez Serrano, María; Martínez de la Casa, Nieves; Romero Puertas, María C.; Río Legazpi, Luis Alfonso del; Sandalio González, Luisa María

    2008-01-01

    El cadmio es un metal pesado no esencial y poco abundante en la corteza terrestre, sin embargo en las últimas décadas ha aumentado considerablemente su acumulación, como consecuencia de la actividad industrial. La contaminación por cadmio puede causar serios problemas a todos los organismos vivos, resultando altamente tóxico para el ser humano. Una posible fuente de contaminación por cadmio en humanos es la ingesta de plantas contaminadas por el metal. Por este motivo, es importante ...

  9. Toxicidad del Cadmio en Plantas

    OpenAIRE

    M. Rodríquez-Serrano; N. Martínez-de la Casa; M.C. Romero-Puertas; Del Río, L A; Sandalio, L M

    2008-01-01

    El cadmio es un metal pesado no esencial y poco abundante en la corteza terrestre, sin embargo en las últimas décadas ha aumentadoconsiderablemente su acumulación, como consecuencia de la actividad industrial. La contaminación por cadmio puede causar serios problemas a todos los organismos vivos, resultando altamente tóxico para el ser humano. Una posible fuente de contaminación por cadmio en humanos es la ingesta de plantas contaminadas por el metal. Por este motivo, es importante conocer c...

  10. Efecto de dos metales pesados, cadmio y níquel, sobre la eficiencia de remoción de carga orgánica de un reactor UASB a escala de laboratorio

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    Luis Eduardo Forero

    2004-01-01

    Full Text Available Se realizaron ensayos en tres reactores UASB de tres litros cada uno, a un tiempo de retención hidráulico (TRH de cuatro horas y carga orgánica volumétrica de 4,8 g/L/d. Después de la fase inicial de arranque, tiempo de 4.000 horas para los tres reactores, se procedió a afectarlos de la siguiente forma: el primer reactor fue alimentado con 5 mg/L de cloruro de cadmio en forma continua, el segundo reactor fue alimentado con 10 mg/L de cloruro de níquel en forma continua también, mientras que el tercer reactor no se afectó con sustancia alguna y sirvió como control. La eficiencia de remoción de demanda química de oxígeno (DQO del primer reactor cambió del 60% de la fase de arranque (fase 1 al 18% en la fase afectada con cadmio (fase dos; la eficiencia de remoción de DQO en el reactor dos pasó del 60 al 24% y a su vez para el reactor tres control no hubo cambio significativo en dicha eficiencia. A su vez el reactor uno acumuló el cadmio en el lodo, mientras que el reactor dos no hizo lo propio con el níquel.

  11. The Cadmio XML healthcare record.

    Science.gov (United States)

    Barbera, Francesco; Ferri, Fernando; Ricci, Fabrizio L; Sottile, Pier Angelo

    2002-01-01

    The management of clinical data is a complex task. Patient related information reported in patient folders is a set of heterogeneous and structured data accessed by different users having different goals (in local or geographical networks). XML language provides a mechanism for describing, manipulating, and visualising structured data in web-based applications. XML ensures that the structured data is managed in a uniform and transparent manner independently from the applications and their providers guaranteeing some interoperability. Extracting data from the healthcare record and structuring them according to XML makes the data available through browsers. The MIC/MIE model (Medical Information Category/Medical Information Elements), which allows the definition and management of healthcare records and used in CADMIO, a HISA based project, is described in this paper, using XML for allowing the data to be visualised through web browsers.

  12. Impacto del CO2 sobre la densidad celular en seis cepas de microalgas marinas

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    Alberto I. Oscanoa Huaynate

    2015-12-01

    Full Text Available Debido a la gran facilidad con que las microalgas pueden capturar el CO2 del medio ambiente, resulta interesante evaluar la cantidad y tiempo de ingreso de éste a los cultivos masivos, con la fi nalidad de aumentar la densidad celular. El objetivo del presente estudio fue evaluar los tiempos de inyección del mencionado gas, durante la producción de biomasa que conlleve a una mayor densidad celular, evaluando además, la variación del pH sin alterar la calidad del cultivo. A partir de seis cepas obtenidas del Banco de Germoplasma del Instituto del Mar del Perú, se realizaron cultivos tipo batch de 300L en invernadero, el tiempo de cultivo de la fase exponencial donde se realizaron las pruebas fue de tres días. Los datos se procesaron mediante el análisis del parámetro pendiente de la regresión lineal. Los resultados mostraron que la densidad celular es inversamente proporcional al tiempo de inyección de CO2 al cultivo. La mayor densidad celular, en las diferentes cepas, se obtuvo a los 5min, excepto para las cepas Chaetoceros gracilisy Nannochloris maculata, las cuales obtienen la mayor densidad a los 10 y 15min, respectivamente. La variación de pH tendió hacia la acidez, en un rango de 8 a 4, sin alterar la densidad celular, por el contrario, los cultivos permanecieron libres de contaminantes. En conclusión, los resultados permiten establecer tiempos adecuados de inyección del CO2, los cuales fortalecen la fase de crecimiento exponencial aumentando la densidad poblacional en un 30% sobre lo establecido en esta fase.

  13. ESTADO ACTUAL DEL CONOCIMIENTO SOBRE MICROALGAS DEL PERIFITON Y MACROINVERTEBRADOS BENTÓNICOS EN EL DEPARTAMENTO DEL META, COLOMBIA

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    Fabián MORENO RODRIGUEZ

    2017-01-01

    Full Text Available El departamento del Meta cuenta con un elevado potencial hidrológico que se traduce en oportunidades para los sectores agrícola, pecuario y ambiental. Por otra parte, se han incrementado considerablemente las actividades de la industria petrolera, lo cual ha traído nuevos retos y amenazas a la región. En consecuencia, los ríos del departamento se ven afectados por vertimientos de diferentes tipos, por captaciones y por modificaciones de los entornos de ribera y de los ambientes bentónicos. Sin embargo, es poco lo que se conoce acerca de estos sistemas y de las comunidades de microalgas y macroinvertebrados que los habitan, las cuales cumplen un papel fundamental en el funcionamiento ecológico de los ríos. Por esta razón se analizan las características más relevantes de dichas comunidades y se discuten las modificaciones que las actividades humanas provocan sobre la estabilidad ecológica de los ríos en un contexto regional. Adicionalmente, se presenta un listado de los taxones de microalgas perifíticas y macroinvertebrados bentónicos registrados para el departamento del Meta.

  14. Preliminary observations of cadmium and copper effects on juveniles of the polychaete Capitella sp. Y (Annelida: Polychaeta from Estero del Yugo, Mazatlán, México Observaciones preliminares de los efectos de cadmio y cobre sobre juveniles del poliqueto Capitella sp. Y (Annelida: Polychaeta del Estero del Yugo, Mazatlán, México

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    NURIA MÉNDEZ

    2005-12-01

    Full Text Available The effects of cadmium (Cd and copper (Cu on cultured juveniles of Capitella sp. Y were investigated. Seven-day old juveniles were exposed to 13 (control, 60, 160, 240 and 340 mg Cd L-1 and 17 (control, 50, 120 and 150 mg Cu L-1 for 30 days. Mortality significantly increased with increasing Cu concentrations, but in Cd exposures, it was only evident at 340 mg L-1. Body size and faecal pellet production were reduced earlier in juveniles exposed to Cu than those exposed to Cd, especially in the higher Cu concentrations. These facts indicate that juveniles are more sensitive to Cu in terms of mortality, feeding and growth. Haemoglobin production was inhibited due to the scarcity of food in the experimental sediment rather than to metal exposure. Tube building was not affected by the presence of metals or by the scarcity of food. This study suggests that Cu concentrations from 50 to 150 mg L-1 and 340 mg L-1 of Cd could affect the population dynamics of this species in natural ecosystemsSe investigaron los efectos de cadmio (Cd y cobre (Cu sobre juveniles cultivados de Capitella sp. Y. Organismos juveniles de siete días de edad fueron expuestos a 13 (control, 60, 160, 240 y 340 mg Cd L-1 y a 17 (control, 50, 120 y 150 mg Cu L-1 durante 30 días. La mortalidad se incrementó significativamente al aumentar las concentraciones de Cu y, en las exposiciones a Cd, solamente fue evidente a 340 mg L-1. El tamaño corporal y la producción de heces fecales disminuyeron antes en los especímenes expuestos a Cu que en los expuestos a Cd, especialmente en las concentraciones más altas de Cu. Estos resultados indican que los juveniles son más sensibles al Cu en términos de mortalidad, alimentación y crecimiento. La producción de hemoglobina fue inhibida debido a la escasez de alimento en el sedimento experimental, más que a exposición a los metales. La formación de tubos no fue afectada por la presencia de metales ni por la escasez de alimento. Este

  15. Valoración del riesgo en salud en un grupo de población de Cali, Colombia, por exposición a plomo, cadmio, mercurio, ácido 2,4-diclorofenoxiacético y diuron, asociada al consumo de agua potable y alimentos

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    Ghisliane Echeverry

    2015-08-01

    Conclusiones. Se cree que los hallazgos sobre contaminantes en estudios anteriores, pueden deberse a eventos puntuales de contaminación y se recomienda vigilar la bocatoma de agua y emitir alertas tempranas. El reporte sobre la presencia de cadmio en las muestras de pescado, sugiere que el control de la calidad de los alimentos por parte de las entidades reguladoras debe mejorar.

  16. Tóxidad de cadmio y plomo en pasto tanner Brachiaria arrecta

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    Manuel Peláez

    2014-12-01

    Full Text Available Se evaluó fisiopatías en Brachiaria arrecta expuestas a contenidos tóxicos de cadmio y plomo en el invernadero de la Universidad Nacional de Colombia Sede Palmira, se doparon plántulas sanas de 20 días de edad bajo cultivo hidropónico. El objetivo fue describir síntomas crecientes por intoxicación con el diseño de una escala valorativa de daños crecientes, adicionalmente se evaluaron cambios histológicos de raíz tallo y hojas mediante microscopia de luz de alta resolución (MLAR. Las plantas fueron sometidas a estrés abiótico con los tratamientos de sales de CdCl2 en concentración de 10 ppm, y de Pb (NO32 500 ppm, respectivamente. Los resultados principales mostraron un mayor detrimento cuando las plantas fueron expuestas al metal plomo que al cadmio en las raíces, tallos y hojas. Se apreciaron deformaciones extremas en paredes celulares de las células del cortex y en la endodermis de la raíz; en las hojas los daños fueron notorios para ambos metales sobre todo en el parénquima clorofílico y en la deformación de paredes de la epidermis tanto en haz como envés; en los tallos aparecieron deformaciones de las células del parénquima de relleno cuando ocurre bioacumulación intensa de plomo. Estos resultados sugieren que la bioconcentración en los tejidos vegetales ocasiona trastornos histológicos, que pueden involucrar una red trófica y por consiguiente consecuencias en la Salud Pública.

  17. Fitoextracción en suelos contaminados con cadmio y zinc usando especies vegetales comestibles

    OpenAIRE

    Beltrán Villavicencio, Margarita

    2003-01-01

    En este trabajo se presenta un estudio de fitoextracción en suelos contaminados con cadmio y cadmio-zinc a través de especies vegetales comestibles como la lechuga (Lactuga sativa) en dos variedades, la de hoja rizada (Lactuca sativa crispa) y la romana (Lactuca sativa longifolia), el calabacín (Cucurbita moschata) y el girasol (Helianthus annus). El objetivo fue evaluar la capacidad de asimilación y concentración de cadmio y zinc por las especies vegetales mencionadas como un proceso de rest...

  18. Determinación de los niveles de plomo y cadmio en leche procesada en la ciudad de Bogotá D.C.

    OpenAIRE

    Pinzon Choque, Carlos Giovanni

    2015-01-01

    La leche y los productos lácteos han sido reconocidos en todo el mundo por su influencia beneficiosa sobre la salud humana. Los niveles de metales en concentraciones tóxicas son un componente importante de la seguridad y la calidad de la leche. Se desarrolló un método sencillo de extracción (digestión) asistida por microondas para la determinación posterior de los niveles de cadmio (Cd) y plomo (Pb) en leche líquida por espectrofotometría de absorción atómica (AAE) con horno de grafito. Se ap...

  19. Estudio isotérmico de biosorción de cromo y cadmio en solución acuosa utilizando residuos de césped

    OpenAIRE

    Andrango Caizapanta, Daniel Xavier

    2012-01-01

    A nivel mundial la contaminación con metales pesados ha dejado una triste secuela de tragedias ecológicas de gran impacto sobre el ambiente global. Por citar un caso: en el año de 1998 en Coto de Donana, aproximadamente un millón de metros cúbicos de lodos que contenían cadmio y otros metales terminaron en el río Guadimar afectando significativamente los sensibles lugares de reproducción aviar. En el Ecuador la situación no es menos alarmante, por ejemplo, en un estudio r...

  20. Mecanismos de resistencia a Metales tóxicos (CD bajo variaciones abióticas en Microalgas

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    Alondra A. Cortés Téllez

    2018-01-01

    Full Text Available En los ecosistemas acuáticos, la presencia de ciertos metales (Cu, Zn, Fe a concentraciones traza son esencialespara distintas actividades biológicas. Sin embargo, otros metales como el Cd y Pb son considerados tóxicos aconcentraciones muy bajas y no participan como micronutrientes. Estos metales interactúan con componentesesenciales a través de enlaces iónicos y covalentes induciendoestrés oxidativo, reemplazo de cationes esenciales,etc. Asimismo, presentan la capacidad de acumularse y biomagnificarse a lo largo de la cadena trófica, promoviendoalta sensibilidad en la mayoría de los organismos acuáticos, mientras que otros como las microalgas, han desarrolladouna gran variedad de estrategias de detoxificación para minimizar los efectos tóxicos de losmetales a través de lainducción de mecanismos de adaptación y resistencia que les permiten la supervivencia a esos ambientes extremos.Por ende, es indispensable conocer la gama de mecanismos de resistencia que estos organismos presentan a laexposición de metales tóxicos presentes en el ecosistema acuático. Así, los objetivos de esta revisión son: identificary describir los principales mecanismos moleculares actualmente descritos en microalgas verdes implicados en laresistencia a metales tóxicos en relación específica con el cadmio; dar a conocer la influencia de distintos factoresambientales sobre esta respuesta y los episodios de corresistencia hacia otros metales de carácter tóxico.

  1. Contenido de plomo y cadmio en aceites de girasol

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    López Martínez, M. C.

    2001-08-01

    Full Text Available We have studied the lead and cadmium content in 21 samples of sunflower oil from Andalucía (Southern Spain. These elements are toxicological importance and the sunflower oil is widely consumed in Spain. Samples were mineralized with nitric acid and vanadium pentoxide as catalyst, and ana lyzed using electrothermal atomization atomic absorption spectroscopy. The temperature-time programme for the graphite furnace was optimized for each element, and the accuracy, precision, sensitivity and detection limit of the method were evaluated. Concentrations of lead ranged from not detectable to 167.58 μg/kg and cadmium concentrations ranged from 0.87 to 8.30 μg/kg. The data obtained are not excessive and similar to those mentioned by other authors; however, one sample of the total analyzed surpassed the limit of 0.1 ppm of lead proposed by the Spanish and European Legislation. A statistical significative correlation has been established between Pb and Cd levels (p Se ha determinado el contenido de plomo y cadmio en 21 muestras de aceite de girasol, todas ellas producidas en Andalucía (Sur de España. Ambos elementos tienen una gran importancia toxicológica y el aceite de girasol es muy consumido en España. Las muestras han sido mineralizadas con ácido nítrico, utilizando pentóxido de vanadio como catalizador, y analizadas mediante espectroscopia de absorción atómica con atomización electrotérmica. Se ha optimizado el programa temperatura-tiempo del horno de grafito para cada elemento y se ha evaluado la exactitud, precisión, sensibilidad y límite de detección del método. Las concentraciones de plomo han oscilado entre no detectables y 167.58 μg/kg y las concentraciones de cadmio entre 0.87 y 8.30 μg/kg. Estos datos no resultan excesivos y concuerdan con los aportados por otros autores; no obstante, una de las muestras analizadas supera el límite máximo de 0.1 ppm de Pb establecido en las Legislaciones Española y Europea. Se

  2. 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

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    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.

  3. Microalgae Nutraceuticals

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    Marcello Nicoletti

    2016-08-01

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

  4. Movilidad del cadmio en suelos cultivados con trigo en Tangua, Nariño, Colombia

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    Menjivar F. Juan

    2006-06-01

    Full Text Available

    En muestras de suelo colocadas en núcleos de PVC (11 cm de diámetro y 40 cm de largo se aplicaron en forma fraccionada 0, 50, 100 y 150 ppm de cadmio y se incubaron por cuatro meses manteniendo la humedad a capacidad de campo. Se evaluó el contenido de Cd-total y Cd – intercambiable en la parte superior, media e inferior de los núcleos. Los contenidos de Cd- total en el testigo no sobrepasaron el límite permisible de 3 ppm esta­blecido por OMS-FAO. La mayor concentración Cd – total aplicado y Cd intercambiable se encontró en la parte superior de los núcleos, lo cual indica baja movilidad del cadmio en el perfil de los suelos evaluados.

    Palabras claves: Cadmio Triticum aestivum, Nariño, suelos

  5. Dinámica del cadmio en suelos cultivados con papa en Nariño, Colombia.

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    Liliana Insuasty B

    2008-01-01

    Full Text Available Se evaluó la fijación y movilidad de cadmio en suelos dedicados al cultivo de papa en Túquerres, Pasto y Guachucal. Se tomaron muestras de suelos no disturbadas en cilindros de PVC, las cuales, luego de aplicaciones fraccionadas de cadmio con dosis de 0, 50,100 y 150 ppm, se incubaron a capacidad de campo durante cuatro meses. En estos suelos los contenidos de cadmio total e intercambiable no sobrepasaron los límites permisibles establecidos por Organización Mundial de la Salud-Organización de las Naciones Unidas para la Agricultura y la Alimentación (OMS-FAO; no obstante, la mayor cantidad del elemento se localizó en la parte superior de los núcleos, lo cual indica baja movilidad del elemento en el perfil.

  6. Estudio de los niveles de plomo, cadmio, zinc y arsénico, en aguas de la provincia de Salamanca

    OpenAIRE

    Blanco Hernández Angel Luis; Alonso Gutiérrez Dionisio; Jiménez de Blas Oroncio; Santiago Guervós Margarita; Miguel Manzano Benito de

    1998-01-01

    FUNDAMENTOS: Conocer el grado de contaminación por plomo, cadmio, cinc y arsénico de las aguas de la provincia de Salamanca y su relación con la zona de procedencia de las muestras y el punto de recogida de las mismas. MÉTODO: Estudio epidemiológico transversal, observacional y descriptivo. Se han estudiado aguas procedentes de redes de abastecimiento, fuentes, manantiales, pozos, ríos, riveras y lagunas de la provincia de Salamanca, analizándose los contenidos de plomo, cadmio, zinc y arséni...

  7. Contaminación de alimentos marinos por cadmio en Lima, 2015

    Directory of Open Access Journals (Sweden)

    Gloria Marín Vallejos

    2015-12-01

    Full Text Available Los objetivos fueron determinar las concentraciones de cadmio en ocho especies de alimentos marinos y comparar con los valores máximos permitidos según la Comisión de la Unión Europea en su Reglamento (CE Nº 1881/2006 y su modificatoria Reglamento (UE N° 488/2014. La investigación fue de carácter descriptivo, trasversal. Las muestras fueron de 100 g de cada ejemplar de pescado en tres oportunidades; los ejemplares fueron: jurel (Trachurus picturatus murphyi, langostinos (Penaeus vannamei, conchas abanico (Argopecten purpuratus, conchas blancas (Semele sp, choros (Aulacomya ater, almejas (Gari solida, machas (Mesonesma donacium y pota (Dosidicus gigas recolectadas al azar en el terminal pesquero de Villa María del Triunfo, provenientes del litoral de la región Lima, sub área 3: Chorrillos – Islas Pachacámac. El proceso de análisis se realizó por espectrofotometría de absorción atómica. Como resultados de los promedios de las concentraciones de cadmio tenemos: en pescados, jurel (Trachurus picturatus murphyi fue 0,35 mg/kg peso fresco; en crustáceos, langostino (Penaeus vannamei fue 0,42 mg/kg peso fresco; en moluscos bivalvos tenemos conchas blancas (Semele sp, conchas abanico (Argopecten purpuratus, choros (Aulacomya ater, machas (Mesonesma donacium y almejas (Gari solida fueron 0,82 – 0,83 – 1,00 – 1,28 y 1,39 mg/kg peso fresco respectivamente. Con este estudio se concluyó que las concentraciones de cadmio en pescados, en moluscos bivalvos y cefalópodos superan los límites permitidos, pero en crustáceos no superan estos límites.

  8. Cuantificación de plomo, cadmio y cromo mediante sialoquímica

    OpenAIRE

    Mireya González

    1997-01-01

    Objetivo. Determinar las concentraciones de plomo, cadmio y cromo, y establecer su posible asociación con diferentes factores sociodemográficos. Material y métodos. Se seleccionó una muestra representativa de 100 estudiantes de posgrado de la Facultad de Odontología de la Universidad Nacional Autónoma de México (UNAM), a los cuales se les colectó saliva total no estimulada. Dichas muestras fueron analizadas por espectrofotometría de absorción atómica con horno de grafito. Resultados. Metales ...

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

    Directory of Open Access Journals (Sweden)

    Luis R Martínez-Córdova

    2012-03-01

    Full Text Available Microalgae Chaetoceros muelleri was cultured in three different mediums consisting on an agricultural fertilizer (Agr-F, aquacultural fertilizer (Aq-F and a conventional medium (F/2, control. These microalgae were later used as natural food to culture the copepod Acartia sp. The productive response and chemical proximate composition of microalgae and copepods were monitored. Growth rate and final cell concentration were higher in microalgae cultured in Agr-F compared to the control. In addition, the final biomass and cellular concentration were also the highest in Agr-F. Microalgae from Agr-F and Aq-F had higher carbohydrate and lower protein contents than those in the control. No differences in lipid and ash contents were observed. Regarding copepod production, higher densities and fecundity indexes were observed for those fed with microalgae previously cultured in Agr-F and Aq-F, compared to the control. The adult-nauplii ratio was also higher in copepods fed on microalgae from Agr-F compared to Aq-F and control. Copepods fed on Agr-F and Aq-F microalgae, had higher protein content compared to those fed on control microalgae; carbohydrates were higher in copepods fed on Agr-F as compared to Aq-F microalgae. No differences in lipid and ash contents were registered. Agr-F and Aq-F were adequate alternative mediums to produce C. muelleri, which produced higher quality microalgae that increased the copepod production.La microalga Chaetoceros muelleri fue cultivada en tres medios diferentes basados en un fertilizante agrícola (Agr-F, un fertilizante acuícola (Aq-F y un medio convencional (F/2, control. Éstas microalgas fueron posteriormente utilizadas como alimento natural para cultivar el copépodo Acartia sp. La respuesta productiva y la composición proximal de las microalgas y copépodos fueron monitoreadas. La tasa de crecimiento y concentración final de células fueron mayores en la microalga cultivada en Agr-F, comparada con el control

  10. Análisis de cadmio y plomo en aguas superficiales por potenciometría de stripping

    OpenAIRE

    Arias, Juan Miguel; Marciales Castiblanco, Clara

    2010-01-01

    Se realizó la implementación y validación de una metodología analítica para determinar la presencia de cadmio y plomo en aguas supjerficiales como herramienta para la descripción del estado actual y el control cualitativo y cuantitativo de las descargas de estos metales peligrosos en los cuerpos de agua.

  11. Análisis de Cadmio y Plomo en aguas superficiales por potenciometría de Stripping

    OpenAIRE

    Juan Miguel Arias; Clara Marciales Castiblanco

    2010-01-01

    Se realizó la implementación y validación de una metodología analítica para determinar la presencia de cadmio y plomo en aguas supjerficiales como herramienta para la descripción del estado actual y el control cualitativo y cuantitativo de las descargas de estos metales peligrosos en los cuerpos de agua.

  12. Efecto del nitrógeno inorgánico (NO-3 sobre el crecimiento y la composición bioquímica de la microalga Scenedesmus sp. Cepa Laun 0001

    Directory of Open Access Journals (Sweden)

    Chaparro de Valencia Martha

    2004-12-01

    Full Text Available Se evaluó el efecto de seis concentraciones de nitrógeno en forma de nitrato, sobre el crecimiento y la composición bioquímica de la microalga cepa LAUN 0001 de Scenedesmus sp. (Chlorophyceae, aislada en el laboratorio de cultivo de microalgas de la Universidad Nacional de Colombia, en un
    lote de cultivos discontinuos, aireados permanentemente. Se estableció que en la razón de 3,5:1 de N:P, se obtiene el mejor rendimiento celular (18.280.000 + 2.820.000 células/ml con una tasa de crecimiento neta alta (2,9 a los siete días. La tasa de crecimiento instantánea no presentó diferencias significativas en los valores para cada tratamiento aplicado, pero se observó una tendencia general de incremento en los tratamientos con mayor concentración. La forma colonial de cuatro células por cenobio predominó en todos los tratamientos aplicados. La concentración de lípidos y carbohidratos se incrementó significativamente en los tratamientos con baja concentración
    de nitrógeno (61-77 pg/célula, mientras que en la  concentración de proteínas y clorofila no se observaron cambios significativos. La concentración de clorofila b fue levemente mayor con respecto a la clorofila a (2,65-3,42 contra 2,33-2,8 pg/célula; la concentración de carotenos fue baja en todos los tratamientos (0,62-0,76 pg/célula aumentando  significativamente en el tratamiento donde la razón de N:P es de 14:1 (1,03 pg/célula. Los valores altos registrados en los diferentes parámetros evaluados y el fácil manejo de la cepa, hacen de esta un modelo promisorio para la realización de estudios a nivel ecológico o biotecnológico.

  13. Outdoor production of microalgae

    NARCIS (Netherlands)

    Vree, de Jeroen H.

    2016-01-01

    This thesis describes the production of microalgae under outdoor conditions, for this research was done at pilot scale. Microalgae are an interesting alternative to currently used sources for bulk commodities as food, feed and chemicals. Research activities within the field are shattered; different

  14. 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.

  15. 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.

  16. Cuantificación de plomo, cadmio y cromo mediante sialoquímica

    Directory of Open Access Journals (Sweden)

    GONZÁLEZ MIREYA

    1997-01-01

    Full Text Available Objetivo. Determinar las concentraciones de plomo, cadmio y cromo, y establecer su posible asociación con diferentes factores sociodemográficos. Material y métodos. Se seleccionó una muestra representativa de 100 estudiantes de posgrado de la Facultad de Odontología de la Universidad Nacional Autónoma de México (UNAM, a los cuales se les colectó saliva total no estimulada. Dichas muestras fueron analizadas por espectrofotometría de absorción atómica con horno de grafito. Resultados. Metales pesados como el plomo, el cadmio y el cromo se encuentran en concentraciones mucho más altas que las informadas en la literatura: Pb, = 3.10 m g/dL-1, máxima: 16.8 my g/dL-1, y mínima: 0.04 my g/dL-1; Cd, = 0.25 my g/dL-1, máxima: 2.04 my g/dL-1, y mínima: 0.004 my g/dL-1; y Cr, = 1.43 my g/dL-1, máxima: 4.82 my g/dL-1, y mínima: 0.05 my g/dL-1. Asimismo, variables como la zona de residencia, el sexo, la edad y la ingesta de comida enlatada no influyen en los niveles de plomo y cromo. Sin embargo, en el caso del cadmio y la edad existe una asociación inversa (ji²= 5.9012, p<= 0.05; gamma = -0.5224, p<= 0.05. Conclusiones. La sialoquímica juega un papel importante en la detección de contaminantes, fármacos, drogas y enfermedades locales y sistémicas. La contaminación por metales pesados sigue siendo un problema de salud pública, por lo que el gobierno debe consolidar un programa cuyo objetivo sea eliminar los diferentes contaminantes del ambiente. Asimismo, se deben realizar otros estudios para verificar la asociación de variables como sexo, edad, uso de cerámica vidriada, alimentación y zona de residencia con las concentraciones de metales pesados en saliva.

  17. Cadmio en sangre y su relación con el consumo de tabaco en una población laboral hospitalaria

    Directory of Open Access Journals (Sweden)

    Avellaneda Díaz Díaz

    2012-12-01

    Full Text Available La exposición de la población general al cadmio es un problema de salud pública, siendo las principales fuentes tanto el consumo de tabaco como la exposición al humo del mismo.El objetivo de este trabajo fue determinar la concentración de cadmio en sangre en una población laboral hospitalaria y su asociación con el consumo de tabaco.Se administró el cuestionario PESA® a 395 sujetos. El cadmio en sangre se midió por espectrometría de absorción atómica con atomización electrotérmica.La mediana de cadmio en sangre fue 0,29 μg/L. La mediana de cadmio de los fumadores (0,83 μg/L fue la más elevada y la de los exfumadores (0,31 μg/L fue a su vez más elevada que la de aquellos que nunca habían fumado (0,21 μg/L. Dentro del grupo de fumadores, se observó una asociación entre la concentración de cadmio y el número de cigarrillos inhalados.En el grupo de exfumadores se observó una asociación con el número de cigarrillos que habían consumido y una correlación negativa entre el tiempo transcurrido desde el abandono del hábito tabáquico y la concentración de cadmio en sangre.Dentro del grupo de los que nunca habían fumado, se observó una diferencia entre la concentración de cadmio de los fumadores pasivos (0,24 μg/L y los que no lo eran (0,20 μg/L.La concentración de cadmio en sangre se relacionó con el consumo de tabaco. Son necesarios más estudios para confirmar el hallazgo de concentraciones de cadmio más elevadas en los fumadores pasivos.

  18. Variabilidad estacional de cadmio en un sistema de surgencia costera del norte de Chile (Bahía Mejillones del Sur, 23° S Seasonal variability of cadmium in a coastal upwelling system off northern Chile (Mejillones bay, 23° S

    Directory of Open Access Journals (Sweden)

    JORGE VALDÉS

    2006-12-01

    Full Text Available Entre junio de 2002 y abril de 2003 se midió el contenido de cadmio total y disuelto entre la superficie y los 100 m de profundidad, en dos estaciones localizadas en la bahía Mejillones del Sur. El rango de cadmio total y cadmio disuelto en las aguas de esta bahía fue 0,41-10,7 y 0,08-1,61 nM, respectivamente, durante el período de muestreo. Los resultados fueron correlacionados con la estructura físico-química de la columna de agua al momento del muestreo, de manera de estudiar los patrones de variabilidad estacional de este metal en este sistema de surgencia. Las condiciones oceanográficas imperantes durante este período correspondieron a un año normal (no-El Niño. Las masas de agua presentes en la bahía correspondieron a agua subantártica, subtropical y ecuatorial subsuperficial, con diferentes grados de mezcla y estratificación durante el período de estudio. Los perfiles de cadmio presentaron una distribución vertical clásica de un micronutriente. Sin embargo estos perfiles presentaron leves diferencias que pueden ser atribuidas a la condición de mezcla de las masas de agua al interior de la bahía. Un análisis multivariado de los parámetros registrados indicó que la variación temporal de cadmio en las aguas superficiales está asociada a las fluctuaciones de la clorofila a y la temperatura. Esto sugiere que, a escala estacional, la producción de biomasa fitoplanctónica sería el principal factor que controla la distribución de cadmio en esta bahía. Por otro lado, a pesar de que el cadmio es un metal redox sensitivo no se encontró un efecto significativo de la disponibilidad de oxígeno sobre el comportamiento de este metal, de manera que la condición micróxica de las aguas de fondo de la bahía no sería un factor preponderante en el flujo de cadmio hacia los sedimentos. La razón Cd/PO4 encontrada en Mejillones es similar a la reportada en otras zonas costeras de Chile. Los bajos valores y la tendencia temporal

  19. Análisis de Cadmio y Plomo en aguas superficiales por potenciometría de Stripping

    Directory of Open Access Journals (Sweden)

    Juan Miguel Arias

    2010-12-01

    Full Text Available Se realizó la implementación y validación de una metodología analítica para determinar la presencia de cadmio y plomo en aguas supjerficiales como herramienta para la descripción del estado actual y el control cualitativo y cuantitativo de las descargas de estos metales peligrosos en los cuerpos de agua.

  20. SeCD electronic folder: CADMIO's application for the medical folder of a service for the care of drug addicts.

    Science.gov (United States)

    Della Valle, R M; Baldoni, A; De Rossi, M; Ferri, F

    1998-01-01

    In this paper we will describe the SeCD (Service for the Care of Drug addicts) electronic folder, a specific application of CADMIO [1] (Computer Aided Design for Medical Information Objects) system. CADMIO is a system for the definition, construction and management of multimedia clinical folders. The Ser.T. (Servizio per la Tossicodipendenza/Service for Drug Addicts) has earned a very special place within the Italian clinical structures as well as any service for drug addicts has done in the rest of the world. Such a structure has special needs and the characteristics of its medical folders are very different from any other folder. Actually, a Ser.T. has to keep updated the patient situation either from the clinical point of view as well as the psychiatric one. Moreover, it must keep track of the clinician subjective considerations about the patient psychic state and his situation in regard of the law. So, we had to redesign some of the features of the existing CADMIO application, to accommodate such highly not structured data into objects easily manipulated by an informative system. The objectives we hope to achieve were mainly two: To show that a well designed adaptive system can be easily exploited to support even very complex and poorly structured data types and actions To design data structures able to accommodate medical, psychiatric and administrative data in an homogeneous manner.

  1. Microalgae: biofuel production

    OpenAIRE

    Babita Kumari; Vinay Sharma

    2013-01-01

    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....

  2. Evaluación del riesgo por toxicidad crónica a la exposición de cadmio en animales de experimentación

    OpenAIRE

    García Ortiz, Mesías Moisés

    2008-01-01

    El cadmio es un metal que esta tomando importancia en los últimos años como principal contaminante ambiental; por el cual es necesario evaluar el movimiento que tiene en el ecosistema, en las poblaciones expuestas y no expuestas ocupacionalmente. El presente trabajo fue realizado para determinar probables efectos tóxicos crónicos tras administrar cadmio en ratas albinas de la especie rattus novegicus, Cepa Holtzman; tilizando el método directo de administración en el agua bebida. Los nivel...

  3. Determinación de la adsorción de cadmio mediante isotermas de adsorción en suelos agrícolas venezolanos

    OpenAIRE

    Nereida Sánchez; Neudis Subero; Carmen Rivero

    2011-01-01

    El cadmio es un metal pesado que tiende a acumularse en la superficie del suelo. En los últimos años, las actividades antropogénicas han ocasionado un incremento en los niveles de este metal en suelos agrícolas generando gran preocupación ambiental debido a su movilidad y lixiviación en el perfil del suelo y a la facilidad con que es absorbido por las plantas. El objetivo de este trabajo fue determinar la capacidad de adsorción de cadmio, de cuatro suelos venezolanos de uso agrícola con difer...

  4. Estudio del aprovechamiento de residuos orgánicos de cultivos de flores (tallos de rosa) como biosorbente de cadmio para el tratamiento de aguas residuales

    OpenAIRE

    Ordóñez Vinueza, Jorge Luis; Moreno Farfán, Raúl Andrés

    2013-01-01

    En objetivo de la tesis es determinar la capacidad de adsorción de cadmio en los residuos orgánicos de cultivos de flores (tallos de rosa), como biosorbente para el tratamiento de aguas residuales. Por lo tanto, después de realizar una revisión bibliográfica del tema se aplicaron dos metodologías: la primera fue para determinar si el biosorbente era capaz de retener iones metálicos de cadmio y la segunda para establecer la máxima capacidad de retención del metal o contaminante. La primera ...

  5. 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

  6. Bioacumulación de cadmio en ostras de la bahía de Cartagena: Bio-accumulation cadmium in oysters of Cartagena bay

    Directory of Open Access Journals (Sweden)

    Ganiveth Manjarrez Paba

    2008-07-01

    Full Text Available La Bahía de Cartagena es una de los cuerpos de agua más contaminados de la ciudad, probablemente debido a las industrias que yacen a su alrededor, algunas de las cuales vierten sus desechos en ella, con poco o ningún tipo de tratamiento. Actualmente, los metales pesados como el cadmio, las operaciones de dragado y relleno, los efluentes térmicos y la sedimentación están causando la degradación de los ecosistemas de la bahía a una tasa alarmante. Esta investigación determinó las concentraciones de cadmio en ostras capturadas en seis puntos estratégicos de la bahía: Álcalis, Bocachica, Caño de Loro, Caño Zapatero, Ciénaga Honda y Zona Franca. Los resultados revelaron que no existen diferencias estadísticamente significativas entre los valores medios de concentración de Cd en ostras en cada uno de los muestreos realizado, y que Ciénaga Honda y Bocachica fueron las estaciones donde se detectó mayor concentración del metal en ostras (25,79 mg Cd/kg y 15,11 mg Cd/kg, respectivamente. Este estudio evidencia el peligro al que están expuestos los consumidores de ostras capturadas en la Bahía de Cartagena, y permite alertar a las autoridades competentes sobre la vigilancia del control en los puntos críticos.Cartagena Bay is one of the most contaminated bodies of water in the city, probably due to the industries around it; some of them dispose of their waste in it, with little or no treatment. Currently, heavy metals such as cadmium, dredging and filling, thermal effluents and sedimentation are causing the degradation of the ecosystem of the bay at an alarming rate. This investigation found concentrations of cadmium in oysters which are caught in six strategic points of the Bay: Álcalis, Bocachica, Caño Loro, Caño Zapatero, Cienaga Honda, and the Free Zone. The results showed that there were no statistically significant differences between the mean values of Cd concentrations in oysters in each one of the samples taken, and that

  7. Economics of microalgae production

    NARCIS (Netherlands)

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

    2017-01-01

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

  8. 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

  9. Microalgae and wastewater treatment

    Science.gov (United States)

    Abdel-Raouf, N.; Al-Homaidan, A.A.; Ibraheem, I.B.M.

    2012-01-01

    Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and secondary treatment processes of these wastewaters have been introduced in a growing number of places, in order to eliminate the easily settled materials and to oxidize the organic material present in wastewater. The final result is a clear, apparently clean effluent which is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic nitrogen and phosphorus and causes eutrophication and more long-term problems because of refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting step for wastewater treatments, because they provide a tertiary biotreatment coupled with the production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary pollution. In the current review we will highlight on the role of micro-algae in the treatment of wastewater. PMID:24936135

  10. 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

  11. 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

  12. Niveles de plomo y cadmio en agua marina y lapas (Patella vulgata L.) de la Ría de Vigo

    OpenAIRE

    M Pérez López; M.C Nóvoa; Alonso, J.; M. A. García Fernández; M.J. Melgar

    2003-01-01

    El empleo de seres vivos para monitorizar la contaminación por metales pesados en los ecosistemas acuáticos es de extremo interés en el campo de la ecotoxicología. En el presente estudio se han recogido muestras de agua marina y de lapas (Patella vulgata L.) de distintos puntos de la Ría de Vigo, con la intención de determinar en ellos los niveles de plomo y cadmio, por medio de una técnica de voltamperometría. Los resultados obtenidos mostraron una relación estrecha entr...

  13. Estudio de los niveles de plomo, cadmio, zinc y arsénico, en aguas de la provincia de Salamanca

    Directory of Open Access Journals (Sweden)

    Blanco Hernández Angel Luis

    1998-01-01

    Full Text Available FUNDAMENTOS: Conocer el grado de contaminación por plomo, cadmio, cinc y arsénico de las aguas de la provincia de Salamanca y su relación con la zona de procedencia de las muestras y el punto de recogida de las mismas. MÉTODO: Estudio epidemiológico transversal, observacional y descriptivo. Se han estudiado aguas procedentes de redes de abastecimiento, fuentes, manantiales, pozos, ríos, riveras y lagunas de la provincia de Salamanca, analizándose los contenidos de plomo, cadmio, zinc y arsénico de 180 muestras, mediante espectroscopía de absorción atómica. Se han comparado los niveles de contaminación por los cuatro elementos de las muestras de agua entre las cuatro unidades comarcales de la provincia. Se han comparado los niveles de contaminación por los cuatro elementos entre las aguas procedentes de redes de abastecimiento y aquellas muestras de pozos, fuentes, manantiales y aguas de superficie. RESULTADOS: Los resultados indican que un 56% de las muestras analizadas superan las concentraciones máximas admisibles de cadmio, y un 28% del total de muestras analizadas supera las concentraciones máximas admisibles de plomo, según la legislación vigente presentando niveles tolerables de zinc y arsénico. No se han observado diferencias importantes en el grado de contaminación de las aguas por los elementos estudiados entre las cuatro unidades comarcales de la provincia. No se han observado diferencias en los niveles de contaminación por los cuatro elementos entre las aguas procedentes de redes de abastecimientos y aquellas muestras de pozos, fuentes, manantiales y aguas de superficie. CONCLUSIONES: Los resultados sugieren que las aguas de la provincia de Salamanca presentan de forma "natural" altos contenidos de cadmio y plomo, probablemente debido a las características geológicas del terreno.

  14. 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.

  15. 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.

  16. 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

  17. Caracterización química de pigmentos cerámicos a base de sulfoseleniuro de cadmio

    Directory of Open Access Journals (Sweden)

    Gazulla Barreda, M. F.

    2013-12-01

    Full Text Available The present paper addresses the development of a methodology that allows the complete chemical characterisation of zirconcadmium sulfoselenide ceramic pigments including minor and major elements. To develop the methodology, five zircon-cadmium sulfoselenide pigments with different hues were selected, studying the different measurement process steps, from sample preparation to the optimisation of the measurement of the different components of the pigments by spectroscopic techniques (WD-XRF and elemental analysis by combustion and IR detection. The chemical characterisation method developed was validated with synthetic standards prepared from the mixture of certified reference materials and pure oxides because no certified referenced materials of this type of pigments were commercially available. The developed method can be used for a complete chemical characterization of zircon-cadmium sulfoselenide ceramic pigments with a very low uncertainty for all the elements analysed.El objetivo del presente trabajo es el desarrollo de una metodología que permita la caracterización química completa de pigmentos cerámicos a base de sulfoseleniuro de cadmio, incluyendo elementos mayoritarios y minoritarios. Para desarrollar la metodología, se seleccionaron cinco pigmentos a base de sulfoseleniuro de cadmio, estudiando las distintas fases del proceso de medida, desde la preparación de la muestra hasta la optimización de la medida de los distintos componentes de los pigmentos por técnicas espectroscópicas (WD-FRX y análisis elemental por combustión y detección mediante IR. El método de caracterización química desarrollado se validó con patrones sintéticos preparados a partir de la mezcla de materiales de referencia certificados y óxidos puros debido a que no existen comercialmente materiales de referencia certificados de este tipo de pigmentos. Este método se puede utilizar para la caracterización química completa de pigmentos a base de

  18. Citotoxicidad del cadmio en hepatocitos de ratón albino y sus posibles implicaciones en ambientes tropicales

    OpenAIRE

    Letty Marcano; Clarisa de R. Faría; Ingrid Carruyo; Xiomara Montiel

    2006-01-01

    Se realizó un análisis de las alteraciones fenotípicas, estructurales y ultraestructurales inducidas por Cd+2 en hepatocitos de ratón albino suizo. El metal fue suministrado vía oral en solución acuosa de CdCl2 durante 100 días a concentraciones de 50 ppm, 100 ppm y 150 ppm, en los controles la solución de cadmio fue sustituida por agua destilada. Las muestras fueron procesadas utilizando la técnica de inclusión en parafina y teñidas con hematoxilina- eosina para microscopía óptica y por la t...

  19. Evolución temporal de la contaminación por plomo y cadmio en la zona intermareal de la ría de Vigo

    Directory of Open Access Journals (Sweden)

    M. Pérez López

    2004-12-01

    Full Text Available En el presente trabajo se han recogido muestras de lapa (Patella vulgata L. y alga verde (Ulva lactuca en un mismo punto de muestreo de la ría de Vigo, con una periodicidad mensual, a lo largo de un año, analizándose por medio de voltamperometría de redisolución anódica la concentración en dos metales pesados con claras repercusiones toxicológicas, cadmio y plomo, en estas muestras, así como en el agua marina. Los resultados obtenidos mostraron la mayor concentración de ambos metales en los tejidos blandos de las lapas frente a las valvas de estos moluscos, con valores máximos en el caso del plomo próximos a 3 ppm (valva de lapa, mientras que para el cadmio se situó en torno a 1,1 ppm (alga verde. El estudio estadístico permitió poner en evidencia una clara correlación estadística entre los valores de cadmio y plomo cuantificados en las muestras de algas.

  20. 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.

  1. Towards industrial products from microalgae

    OpenAIRE

    Ruiz, Jesús; Olivieri, Giuseppe; de Vree, Jeroen Hendrik; Bosma, Rouke; Willems, Philippe; Reith, J. Hans; Eppink, Michel H.M.; Kleinegris, Dorinde M.M.; Wijffels, Rene Hubertus; Barbosa, Maria J.

    2016-01-01

    Our society needs new sustainable biobased feedstocks to meet population growth and reduce dependence on fossil fuels. Microalgae are considered one of the most promising feedstocks for sustainable production of food, feed, chemicals, materials and fuels. Our mission is to develop a commercial and sustainable production chain for commodity products from microalgae. Estimations of biomass production costs for a 100 ha plant facility have been done. Projections of different scenarios allowed us...

  2. Microalgae, Functional Genomics and Biotechnology

    OpenAIRE

    Cadoret, Jean-Paul; Garnier, Matthieu; Saint-Jean, Bruno

    2012-01-01

    Microalgae have been studied for decades, but a new wave of research has recently begun as part of the search for renewable and sustainable energy sources. For economic optimization, microalgal biomass is being considered as a whole (main products and co-products) in an overall 'biorefinery' concept Applications of microalgae cover a broad spectrum, including the food and (livestock) feed industries, bio-energy, cosmetics, healthcare and environmental restoration or protection. In the field o...

  3. Efecto de metales pesados en el crecimiento de la microalga tropical Tetraselmis chuii (Prasinophyceae

    Directory of Open Access Journals (Sweden)

    Jiudith Cordero

    2005-09-01

    Full Text Available El presente trabajo determina el efecto tóxico de los metales cadmio (Cd, cobre (Cu, mercurio (Hg y plomo (Pb en la microalga tropical Tetraselmis chuii (Butcher, 1959. Se expuso, por triplicado, 50 ml de cultivo (f/2 Guillard de la microalga en fase de crecimiento logarítmica ante las concentraciones de 0 (control; 0.1; 1.0; 5.0; 10.0 y 20.0 mg· l-1 durante 96 hr. La evaluación del efecto letal se realizó diariamente, mediante recuento celular con una cámara de Neubauer. En el tratamiento control, sin exposición al metal, se observó un incremento de la densidad celular, en contraste con un decrecimiento en los tratamientos con exposición a los metales, los cuales fueron acelerados hasta las 48 hr, a partir de cuando el decrecimiento se hizo menos pronunciado. Una excepción se produjo con el Cd y el Cu a las 24 h, donde no se determinó decrecimiento significativo, probablemente debido a su capacidad de actuar como micronutriente a bajas concentraciones. El metal que produjo mayor efecto fue el Pb, produciendo una letalidad al 50% de la población microalgal a 0.40 mg· l-1, la cual fue casi tres veces menor que la establecida para el Hg y más de 13 veces menor que la del Cd y Cu. Se recomienda la microalga Tetraselmis chuii como especie modelo para la utilización en pruebas en función estimar efectos tóxicos por xenobióticos en el ambiente acuático marino tropical.Efect of heavy metals on the growth of the tropical microalga Tetrasermis chuii (Prasinophyceae. We determined the toxic effect of four metals, cadmium (Cd, copper (Cu, mercury (Hg and lead (Pb, on the tropical microalga Tetraselmis Chuii (Butcher, 1959. We exposed 50 ml of cultivated microalgae (f/2 Guillard in the exponential growth phase, with three replicates, to concentrations of 0 (control, 0.1, 1.0, 5.0, 10.0 and 20.0 mg· l-1 with each metal for 96 hr. We evaluated the lethal effect daily, through the cellular count. In the control treatment (not exposed to any

  4. 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.

  5. Microalgae at wastewater treatment in cold climate

    OpenAIRE

    Grönlund, Erik

    2002-01-01

    The thesis concludes that microalgae may improve wastewater treatment in ponds in cold climate, from a treatment perspective as well as a sustainability perspective. A literature review revealed that the microalgae biomass produced may find economic use, depending on what species will come to dominate, since there are many possible products from microalgae biomass. Laboratory experiments showed that microalgae collected in the Mid Sweden region can grow readily in wastewater from the same reg...

  6. Physicochemical analysis of cellulose from microalgae ...

    African Journals Online (AJOL)

    Physicochemical analysis of cellulose from microalgae Nannochloropsis gaditana. ... The progress of the microalgae mass production could help in the substitution of the cellulose of microalgae for the vegetal cellulose, as seen in the simple technical extraction, the yield and the procurement of uncontaminated molecule ...

  7. Flashing light in microalgae biotechnology.

    Science.gov (United States)

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

    2016-03-01

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

  8. 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. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Airborne Microalgae: Insights, Opportunities, and Challenges

    Science.gov (United States)

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

    2016-01-01

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

  10. Valoración del residuo de rapa de uva como bioadsorbente para la eliminación de cadmio de efluentes acuosos

    OpenAIRE

    Moreno Rabasco, Mª Carmen

    2005-01-01

    Los metales pesados son sustancias tóxicas capaces de causar graves daños en los organismos vivos. Una de las principales propiedades de los metales pesados es que no son biodegradables y permanecen durante mucho tiempo en el entorno, circulando y acumulándose en el medio y los seres vivos, por lo que es necesario evitar su incorporación al entorno a través de vertidos contaminados. De entre los distintos metales tóxicos, el cadmio es uno de los más peligrosos. La contaminac...

  11. Evolución temporal de la contaminación por plomo y cadmio en la zona intermareal de la ría de Vigo

    OpenAIRE

    M Pérez López; M. Méndez García; J. Alonso Díaz; M. J. Melgar Riol

    2004-01-01

    En el presente trabajo se han recogido muestras de lapa (Patella vulgata L.) y alga verde (Ulva lactuca) en un mismo punto de muestreo de la ría de Vigo, con una periodicidad mensual, a lo largo de un año, analizándose por medio de voltamperometría de redisolución anódica la concentración en dos metales pesados con claras repercusiones toxicológicas, cadmio y plomo, en estas muestras, así como en el agua marina. Los resultados obtenidos mostraron la mayor concentración de ambos metales en los...

  12. Complejación de plomo(II) y cadmio(II) con nuevos receptores macrocíclicos derivados de azacoronandos

    OpenAIRE

    Esteban Gómez, David

    2017-01-01

    [Resumen] En la presente Tesis Doctoral se describen catorce nuevos receptores macrocíclicos derivados de los coronandos 1,10-diaza-15-corona-5 ó 4,13-diaza-18-corona-6 y se han estudiado sus propiedades coordinantes y capacidad de complejar a los iones metálicos plomo(II) y cadmio(II). Estructuralmente, estos receptores se agrupan en dos clases: 1,- éteres lariat bibraquiales (L1, L2, L3, L4, L5 y L6). 2,- Macrobiciclos laterales (L7, L8, L9, L10, L11, L12, L13 y L14). ...

  13. Cuantificación de plomo, cadmio y cromo mediante sialoquímica Quantification of lead, cadmium and chromium through sialochemistry

    OpenAIRE

    MIREYA GONZÁLEZ; JOSÉ ANTONIO BANDERAS; CLAUDIA RAYA; ARMANDO BÁEZ; RAÚL BELMONT

    1997-01-01

    Objetivo. Determinar las concentraciones de plomo, cadmio y cromo, y establecer su posible asociación con diferentes factores sociodemográficos. Material y métodos. Se seleccionó una muestra representativa de 100 estudiantes de posgrado de la Facultad de Odontología de la Universidad Nacional Autónoma de México (UNAM), a los cuales se les colectó saliva total no estimulada. Dichas muestras fueron analizadas por espectrofotometría de absorción atómica con horno de grafito. Resultados. Metales ...

  14. Elementos traza en alimentos: cadmio y plomo en fruta enlatada por espectrometría de absorción atómica con horno de grafito

    OpenAIRE

    Bedregal, Patricia

    2006-01-01

    Se demuestra la confiabilidad de los resultados de cadmio y plomo informados por el Laboratorio de Química mediante su participación en un Ensayo de Aptitud organizado por la National Food Administration de Suecia. La muestra consistió de fruta enlatada y fue analizada utilizando la técnica de espectrometría de absorción atómica con horno de grafito. The confidence of the results of cadmium and lead reported by the Chemistry Laboratory in its participation in a Proficiency Test organised ...

  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

  16. Towards industrial products from microalgae

    NARCIS (Netherlands)

    Ruiz Gonzalez, Jesus; Olivieri, Guiseppe; Vree, de J.H.; Bosma, R.; Willems, Philippe; Reith, J.H.; Eppink, M.H.M.; Kleinegris, D.M.M.; Wijffels, R.H.; Barbosa, M.J.

    2016-01-01

    Our society needs new sustainable biobased feedstocks to meet population growth and reduce dependence on fossil fuels. Microalgae are considered one of the most promising feedstocks for sustainable production of food, feed, chemicals, materials and fuels. Our mission is to develop a commercial and

  17. Current Status and Prospects of Biodiesel Production from Microalgae

    OpenAIRE

    Xiaodan Wu; Rongsheng Ruan; Zhenyi Du; Yuhuan Liu

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  19. Citotoxicidad del cadmio en hepatocitos de ratón albino y sus posibles implicaciones en ambientes tropicales

    Directory of Open Access Journals (Sweden)

    Letty Marcano

    2006-06-01

    Full Text Available Se realizó un análisis de las alteraciones fenotípicas, estructurales y ultraestructurales inducidas por Cd+2 en hepatocitos de ratón albino suizo. El metal fue suministrado vía oral en solución acuosa de CdCl2 durante 100 días a concentraciones de 50 ppm, 100 ppm y 150 ppm, en los controles la solución de cadmio fue sustituida por agua destilada. Las muestras fueron procesadas utilizando la técnica de inclusión en parafina y teñidas con hematoxilina- eosina para microscopía óptica y por la técnica convencional para microscopía electrónica de transmisión. Identificamos cambios fenotípicos (diferencias entre talla y peso y fisiológicos (debilidad muscular e intranquilidad; a nivel histológico, pérdida de la disposición trabecular y de la arquitectura lobulillar, focos de aglomerados linfocíticos, vacuolización, dilatación de sinosoides y de la vena central. El estudio ultraestructural señala diversas alteraciones tales como: nucléolo con un elevado número de centros fibrilares (50 ppm; voluminosas gotas de lípidos en el citoplasma, retículo endoplasmático rugoso distendido, vacuolización citoplasmática, lisosomas y peroxisomas alterados (100 ppm; núcleos contraídos con cromatina condensada, dilatación en el espacio intracelular y áreas de pérdida mitocondrial y fibrilar (150 ppm. Sugerimos que el cadmio ejerce un efecto tóxico en las células hepáticas el cual se hace más severo con el aumento de la concentración, llevando a la necrosis celular.Cadmium citotoxicity in mice hepatocytes and impications on tropical environments. We analyzed phenotypic, structural and ultrastructural alterations induced by Cd+2 in hepatocytes extracted from Swiss Albino mice. Cadmium was given orally in watery solution of CdCl2 during 100 days at concentrations of 50 ppm, 100 ppm and 150 ppm. In controls, distilled water alone was used. The samples were processed with the paraffin inclusion and hematoxilin-eosin coloration

  20. 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.

  1. 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

  2. ECUACIÓN DE VELOCIDAD PARA LA ADSORCIÓN SOBRE UNA BENTONITA.

    Directory of Open Access Journals (Sweden)

    David Rodríguez

    2008-03-01

    Full Text Available Se estudió la adsorción de dodecilbencenosulfonato de sodio, a 25 oC, sobre arcillas organofílicas obtenidas tratando una bentonita del Valle del Cauca con iones hexadeciltrimetil amonio y hexadecilbencildimetil amonio. El proceso de adsorción es relativamente rápido. Igualmente, se estudió la adsorción de cadmio, niquel y zinc sobre la bentonita en estado natural y se encontró que este proceso es muy rápido. En todos los casos estudiados se cumple la ley cinética correspondiente al proceso reversible y a la ecuación de velocidad que incluye la superficie de adsorbente disponible para la adsorción y en la que todos los órdenes parciales son iguales a uno.

  3. Determinación de la adsorción de cadmio mediante isotermas de adsorción en suelos agrícolas venezolanos

    Directory of Open Access Journals (Sweden)

    Subero Neudis

    2011-06-01

    Full Text Available El cadmio es un metal pesado que tiende a acumularse en la superficie del suelo. En los últimos años,las actividades antropogénicas han ocasionado un incremento en los niveles de este metal en suelosagrícolas generando gran preocupación ambiental debido a su movilidad y lixiviación en el perfil delsuelo y a la facilidad con que es absorbido por las plantas. El objetivo de este trabajo fue determinarla capacidad de adsorción de cadmio, de cuatro suelos venezolanos de uso agrícola con diferenciastexturales. Para determinar la capacidad de adsorción del metal en cada suelo, inicialmente se determinóel tiempo óptimo de agitación; el cual fue de 2 horas y la relación suelo-solución enriquecedora de Cd;la cual fue de 1:50. Con estos parámetros se elaboraron las isotermas de adsorción para los suelos y secompararon los modelos de Freundlich y Langmuir. Los resultados mostraron que el modelo matemáticode Freundlich es el que mejor describe la cinética de la reacción y la capacidad de adsorción de Cdpor los suelos, siendo los que poseen mayores contenidos de arcilla, MO y pH ácidos los de mayorcapacidad de adsorción.

  4. 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.

  5. Production of biofuels obtained from microalgae

    OpenAIRE

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

    2012-01-01

    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 importanc...

  6. Biofuels from Microalgae and Seaweeds

    Energy Technology Data Exchange (ETDEWEB)

    Huesemann, Michael H.; Roesijadi, Guritno; Benemann, John; Metting, F. Blaine

    2010-03-01

    8.1 Introduction: Seaweeds and microalgae have a long history of cultivation as sources of commercial products (McHugh 2003; Pulz and Gross 2004). They also have been the subject of extensive investigations related to their potential as fuel source since the 1970s (Chynoweth 2002). As energy costs rise, these photosynthetic organisms are again a focus of interest as potential sources of biofuels, particularly liquid transportation fuels. There have been many recent private sector investments to develop biofuels from microalgae, in part building on a U.S. Department of Energy (DOE) program from 1976 to 1996 which focused on microalgal oil production (Sheehan et al. 1998). Seaweed cultivation has received relatively little attention as a biofuel source in the US, but was the subject of a major research effort by the DOE from 1978 to 1983 (Bird and Benson 1987), and is now the focus of significant interest in Japan, Europe and Korea...

  7. Microalgae as embedded environmental monitors

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-15

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

  8. Production of biodiesel from microalgae

    OpenAIRE

    Danilović, Bojana R.; Avramović, Jelena M.; Ćirić, Jovan T.; Savić, Dragiša S.; Veljković, Vlada B.

    2014-01-01

    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...

  9. Microalgae as embedded environmental monitors.

    Science.gov (United States)

    Ogburn, Zachary L; Vogt, Frank

    2017-02-15

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

  10. Estado actual de las empresas productoras de microalgas destinadas a alimentos y suplementos alimenticios en América Latina

    Directory of Open Access Journals (Sweden)

    Luis Daniel Martínez Angulo

    2017-12-01

    Full Text Available Las microalgas resultan de interés en la producción de alimentos y suplementos debido a su riqueza de nutrientes. Esta revisión tiene como objetivo recopilar información actual sobre el estado de empresas de mediana y gran escala, productoras de biomasa y bioproductos microalgales comercializados como alimento y suplemento alimenticio en América Latina, con el fin de conocer el nivel de desarrollo en la región. El país con mayor cantidad de empresas productoras de alimentos a base de microalgas es Brasil (6, seguido de México, Perú, Chile (2, Ecuador y Cuba (1. El sistema de cultivo más común empleado por empresas latinoamericanas en el comercio de microalgas es el abierto. El organismo más utilizado en productos alimenticios a base de microalgas en Latinoamérica corresponde al género Spirulina. Se ha investigado sobre la composición bioquímica de más de 10 especies de microalgas, a escala de laboratorio. Las microalgas son fuente importante de proteínas y de ácidos grasos del tipo omega-3, así como de vitaminas y minerales. Se evidencia el potencial que tiene Latinoamérica para el desarrollo de nuevas tecnologías de sistemas de cultivo y productos alimenticios a base de microalgas, como alimento para la población como para la exportación. Sin embargo, se requiere de un gran esfuerzo tanto del sector privado como del público para alcanzar los fines.

  11. Closing Domestic Nutrient Cycles Using Microalgae

    NARCIS (Netherlands)

    Vasconcelos Fernandes, T.; Shresthat, R.; Suit, Y.; Papini, G.; Zeeman, G.; Vet, L.E.M.; Wijffels, R.H.; Lamers, P.P.

    2015-01-01

    This study demonstrates that microalgae can effectively recover all P and N from anaerobically treated black water (toilet wastewater). Thus, enabling the removal of nutrients from the black water and the generation of a valuable algae product in one step. Screening experiments with green microalgae

  12. Harvesting and cell disruption of microalgae

    NARCIS (Netherlands)

    Lam, 't Gerard Pieter

    2017-01-01

    Microalgae are a potential feedstock for various products. At the moment, they are already used as feedstock for high-valuable products (e.g. aquaculture and pigments). Microalgae pre-dominantly consist out of proteins, lipids and carbohydrates. This makes algae an interesting feedstock for various

  13. Microalgae for biofuels production and environmental applications ...

    African Journals Online (AJOL)

    Microalgae can provide several different types of renewable biofuels. These include methane produced by anaerobic digestion of the algal biomass; biodiesel derived from microalgal oil and photobiologically produced biohydrogen. This review presents the current classification of biofuels, with special focus on microalgae ...

  14. 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

  15. 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

  16. 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.

  17. Sterols in Microalgae: Euglena gracilis and Selenastrum sp.

    OpenAIRE

    Zhang, Yangyang

    2017-01-01

    The literature review introduced the chemistry of sterols and presented the sterols found in microalgae, and placed emphasis on the analytical methods used for studying sterols in microalgae. A brief discussion about application of microalgae-derived sterols was also included. The aim of this work was to learn about the sterol compositions in microalgae: Euglena gracilis and Selenastrum sp.. The common analytical methods of sterols are not suitable when applied to microalgae. Traditional...

  18. Overcoming Microalgae Harvesting Barrier by Activated Algae Granules

    OpenAIRE

    Tiron, Olga; Bumbac, Costel; Manea, Elena; Stefanescu, Mihai; Nita Lazar, Mihai

    2017-01-01

    The economic factor of the microalgae harvesting step acts as a barrier to scaling up microalgae-based technology designed for wastewater treatment. In view of that, this study presents an alternative microalgae-bacteria system, which is proposed for eliminating the economic obstacle. Instead of the microalgae-bacteria (activated algae) flocs, the study aimed to develop activated algae granules comprising the microalgae Chlorella sp. as a target species. The presence of the filamentous microa...

  19. Determinación de la adsorción de cadmio mediante isotermas de adsorción en suelos agrícolas venezolanos

    Directory of Open Access Journals (Sweden)

    Nereida Sánchez

    2011-04-01

    Full Text Available El cadmio es un metal pesado que tiende a acumularse en la superficie del suelo. En los últimos años, las actividades antropogénicas han ocasionado un incremento en los niveles de este metal en suelos agrícolas generando gran preocupación ambiental debido a su movilidad y lixiviación en el perfil del suelo y a la facilidad con que es absorbido por las plantas. El objetivo de este trabajo fue determinar la capacidad de adsorción de cadmio, de cuatro suelos venezolanos de uso agrícola con diferencias texturales. Para determinar la capacidad de adsorción del metal en cada suelo, inicialmente se determinó el tiempo óptimo de agitación; el cual fue de 2 horas y la relación suelo-solución enriquecedora de Cd; la cual fue de 1:50. Con estos parámetros se elaboraron las isotermas de adsorción para los suelos y se compararon los modelos de Freundlich y Langmuir. Los resultados mostraron que el modelo matemático de Freundlich es el que mejor describe la cinética de la reacción y la capacidad de adsorción de Cd por los suelos, siendo los que poseen mayores contenidos de arcilla, MO y pH ácidos los de mayor capacidad de adsorción.

  20. Global evaluation of biofuel potential from microalgae

    National Research Council Canada - National Science Library

    Jeffrey W. Moody; Christopher M. McGinty; Jason C. Quinn

    2014-01-01

    In the current literature, the life cycle, technoeconomic, and resource assessments of microalgae-based biofuel production systems have relied on growth models extrapolated from laboratory-scale data...

  1. 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.

  2. 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.

  3. Biologically Active Metabolites Synthesized by Microalgae

    Science.gov (United States)

    Costa, Jorge Alberto Vieira

    2015-01-01

    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. PMID:26339647

  4. Microalgae as Solar-Powered Protein Factories.

    Science.gov (United States)

    Hempel, Franziska; Maier, Uwe G

    2016-01-01

    Microalgae have an enormous ecological relevance as they contribute significantly to global carbon fixation. But also for biotechnology microalgae became increasingly interesting during the last decades as many algae provide valuable natural products. Especially the high lipid content of some species currently attracts much attention in the biodiesel industry. A further application that emerged some years ago is the use of microalgae as expression platform for recombinant proteins. Several projects on the production of therapeutics, vaccines and feed supplements demonstrated the great potential of using microalgae as novel low-cost expression platform. This review provides an overview on the prospects and advantages of microalgal protein expression systems and gives an outlook on potential future applications.

  5. Comparison between direct transesterification of microalgae and hydrochar

    Directory of Open Access Journals (Sweden)

    Vo Thanh Phuoc

    2017-07-01

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

  6. Microalgae, old sustainable food and fashion nutraceuticals.

    Science.gov (United States)

    García, José L; de Vicente, Marta; Galán, Beatriz

    2017-09-01

    Microalgae have been used for centuries to provide nourishment to humans and animals, only very recently they have become much more widely cultured and harvested at large industrial scale. This paper reviews the potential health benefits and nutrition provided by microalgae whose benefits are contributing to expand their market. We also point out several key challenges that remain to be addressed in this field. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  7. From tiny microalgae to huge biorefineries

    OpenAIRE

    Gouveia, L.

    2014-01-01

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

  8. Reversible flocculation of microalgae using magnesium hydroxide

    OpenAIRE

    Vandamme, Dries; Beuckels, Annelies; Markou, Giorgos; Foubert, Imogen; Muylaert, Koenraad

    2015-01-01

    Flocculation of microalgae is a promising low-cost strategy to harvest microalgae for bulk biomass production. However, residual flocculants can interfere in further downstream processes or influence biomass quality. In this study, a new concept is demonstrated based on reversible magnesium hydroxide flocculation, using Chlorella vulgaris and Phaeodactylum tricornutum as, respectively, a freshwater and a marine model species. We show that flocculation was induced by precipitation of magnesium...

  9. Efficiency of the biodiesel production from microalgae

    Science.gov (United States)

    Chernova, N. I.; Kiseleva, S. V.; Popel', O. S.

    2014-06-01

    Biomass of the highly productive algae is a promising nontraditional raw material for biopower engineering, including production of energy and motor fuels from it. The paper presents an analysis of the efficiency of solar energy conversion to microalgae biofuel based both on the general theoretical approaches and on the experimental results obtained in various pilot projects. Some data on the economic efficiency of biofuel production from algae are also discussed. The possible ways to enhance the efficiency of microalgae energy use are formulated.

  10. Heavy metal detoxification in eukaryotic microalgae.

    Science.gov (United States)

    Perales-Vela, Hugo Virgilio; Peña-Castro, Julián Mario; Cañizares-Villanueva, Rosa Olivia

    2006-06-01

    Microalgae are aquatic organisms possessing molecular mechanisms that allow them to discriminate non-essential heavy metals from those essential ones for their growth. The different detoxification processes executed by algae are reviewed with special emphasis on those involving the peptides metallothioneins, mainly the post transcriptionally synthesized class III metallothioneins or phytochelatins. Also, the features that make microalgae suitable organisms technologies specially to treat water that is heavily polluted with metals is discussed.

  11. Microalgae for biofuels: the Portuguese experience

    OpenAIRE

    Gouveia, L.; Reis, Alberto; Moura, Patrícia; Oliveira, A. C.; Gírio, Francisco M.

    2015-01-01

    Autotrophic microalgae are photosynthetic organisms that undergo the conversion of light into chemical energy as a form of a wide range of organic compounds through its photosynthetic machinery. The cultivation of microalgae brings environmental advantages, bearing in mind the capability of nutrient recycling in wastewaters together with the fixation of greenhouse gases such as CO2. These micro-organisms have been widely recognized as having huge potential as feedstock for food, feed, pharmac...

  12. 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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  15. 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

  16. Efecto de la calidad de la materia orgánica asociada con el uso y manejo de suelos en la retención de cadmio, en sistemas altoandinos de Colombia

    Directory of Open Access Journals (Sweden)

    Isabel del Socorro Bravo Realpe

    2014-04-01

    Full Text Available El cadmio (Cd proveniente de suelos afectados por intemperismo y actividades antropogénicas puede producir efectos tóxicos, asociados con la baja afinidad de las formas adsorbentes, la alta solubilidad y la movilidad. Es de gran importancia conocer los fenómenos de adsorción y los factores de movilidad de este elemento y predecir su posible toxicidad en suelos de la región altoandina de Colombia cuyo sistema de uso está cambiando a pasturas y cultivos con aplicación de fertilizantes fosfatados que contienen cadmio. Para determinar la influencia en la retención y el factor de movilidad de Cd en estos suelos de la subcuenca Rio Las Piedras, Departamento del Cauca (Colombia, utilizados en sistemas de bosque, cultivo de papa (Solanum tuberosum y pastura de kikuyo (Pennisetum clandestinum fueron caracterizados por sus propiedades físicas y químicas, encontrando alta acidez, presencia de alófanos, alto contenido de carbono orgánico, alta capacidad de intercambio catiónico, y baja densidad. Para determinar la influencia en la retención y el factor de movilidad de cadmio, la calidad de la materia orgánica (M.O fue evaluada mediante índices de humificación obtenidos por la caracterización de sus diferentes fracciones. La retención fue evaluada mediante isotermas de adsorción de Freundlich en ácidos húmicos en suelos de los tres sistemas de uso. Los valores encontrados de K (máxima capacidad de adsorción y n (fuerza de retención fueron, respectivamente, de 131.98 y 1.18 en suelos de bosque, 340.93 y 1.19 en cultivo, y 170.36 y 1.19 en pasturas. La calidad de la M.O. tiene un efecto significativo en estos procesos, así, una mejor calidad redunda en menor movilidad de cadmio, previniendo contaminación de aguas subterráneas y toxicidad por bioacumulación de cadmio.

  17. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. The Potential for Microalgae as Bioreactors to Produce Pharmaceuticals.

    Science.gov (United States)

    Yan, Na; Fan, Chengming; Chen, Yuhong; Hu, Zanmin

    2016-06-17

    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 increased interest. Compared with the bioreactor systems that are currently in use, microalgae may be an attractive alternative for the production of pharmaceuticals, recombinant proteins and other valuable products. Products synthesized via the genetic engineering of microalgae include vaccines, antibodies, enzymes, blood-clotting factors, immune regulators, growth factors, hormones, and other valuable products, such as the anticancer agent Taxol. In this paper, we briefly compare the currently used bioreactor systems, summarize the progress in genetic engineering of microalgae, and discuss the potential for microalgae as bioreactors to produce pharmaceuticals.

  19. The Potential for Microalgae as Bioreactors to Produce Pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Na Yan

    2016-06-01

    Full Text Available 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 increased interest. Compared with the bioreactor systems that are currently in use, microalgae may be an attractive alternative for the production of pharmaceuticals, recombinant proteins and other valuable products. Products synthesized via the genetic engineering of microalgae include vaccines, antibodies, enzymes, blood-clotting factors, immune regulators, growth factors, hormones, and other valuable products, such as the anticancer agent Taxol. In this paper, we briefly compare the currently used bioreactor systems, summarize the progress in genetic engineering of microalgae, and discuss the potential for microalgae as bioreactors to produce pharmaceuticals.

  20. Creating a Collection of Microalgae for use in Biofuels Research

    Science.gov (United States)

    2008-06-25

    Dr. J. Polle – Brooklyn College of CUNY -1- Final Report for the Project: CREATING A COLLECTION OF MICROALGAE FOR USE IN BIOFUELS RESEARCH...For both direct and metabolic engineering approaches to improved biofuels production, it is vital to isolate a large variety of microalgae for...create a culture collection as a resource of diverse microalgae for biofuels research. To this end, from about 50 different habitats novel microalgae

  1. Flocculation based harvesting processes for microalgae biomass production

    OpenAIRE

    Vandamme, Dries

    2013-01-01

    The global demand for biomass for food, feed, biofuels, and chemical production is expected to increase in the coming decades. Microalgae are a promising new source of biomass that may complement agricultural crops. Production of microalgae has so far however been limited to high-value applications. In order to realize large-scale production of microalgae biomass for low-value applications, new low-cost technologies are needed to produce and process microalgae. A major challenge lies in the h...

  2. Harvesting microalgae by bio-flocculation and autoflocculation

    OpenAIRE

    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. 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. Biofouling in photobioreactors for marine microalgae.

    Science.gov (United States)

    Zeriouh, Ouassim; Reinoso-Moreno, José Vicente; López-Rosales, Lorenzo; Cerón-García, María Del Carmen; Sánchez-Mirón, Asterio; García-Camacho, Francisco; Molina-Grima, Emilio

    2017-12-01

    The economic and/or energetic feasibility of processes based on using microalgae biomass requires an efficient cultivation system. In photobioreactors (PBRs), the adhesion of microalgae to the transparent PBR surfaces leads to biofouling and reduces the solar radiation penetrating the PBR. Light reduction within the PBR decreases biomass productivity and, therefore, the photosynthetic efficiency of the cultivation system. Additionally, PBR biofouling leads to a series of further undesirable events including changes in cell pigmentation, culture degradation, and contamination by invasive microorganisms; all of which can result in the cultivation process having to be stopped. Designing PBR surfaces with proper materials, functional groups or surface coatings, to prevent microalgal adhesion is essential for solving the biofouling problem. Such a significant advance in microalgal biotechnology would enable extended operational periods at high productivity and reduce maintenance costs. In this paper, we review the few systematic studies performed so far and applied the existing thermodynamic and colloidal theories for microbial biofouling formation in order to understand microalgal adhesion on PBR surfaces and the microalgae-microalgae cell interactions. Their relationship to the physicochemical properties of the solid PBR surface, the microalgae cell surfaces, and the ionic strength of the culture medium is discussed. The suitability and the applicability of such theories are reviewed. To this end, an example of biofouling formation on a commercial glass surface is presented for the marine microalgae Nannochloropsis gaditana. It highlights the adhesion dynamics and the inaccuracies of the process and the need for further refinement of previous theories so as to apply them to flowing systems, such as is the case for PBRs used to culture microalgae.

  4. Cuantificación de plomo, cadmio y cromo mediante sialoquímica Quantification of lead, cadmium and chromium through sialochemistry

    Directory of Open Access Journals (Sweden)

    MIREYA GONZÁLEZ

    1997-05-01

    Full Text Available Objetivo. Determinar las concentraciones de plomo, cadmio y cromo, y establecer su posible asociación con diferentes factores sociodemográficos. Material y métodos. Se seleccionó una muestra representativa de 100 estudiantes de posgrado de la Facultad de Odontología de la Universidad Nacional Autónoma de México (UNAM, a los cuales se les colectó saliva total no estimulada. Dichas muestras fueron analizadas por espectrofotometría de absorción atómica con horno de grafito. Resultados. Metales pesados como el plomo, el cadmio y el cromo se encuentran en concentraciones mucho más altas que las informadas en la literatura: Pb, = 3.10 m g/dL-1, máxima: 16.8 my g/dL-1, y mínima: 0.04 my g/dL-1; Cd, = 0.25 my g/dL-1, máxima: 2.04 my g/dL-1, y mínima: 0.004 my g/dL-1; y Cr, = 1.43 my g/dL-1, máxima: 4.82 my g/dL-1, y mínima: 0.05 my g/dL-1. Asimismo, variables como la zona de residencia, el sexo, la edad y la ingesta de comida enlatada no influyen en los niveles de plomo y cromo. Sin embargo, en el caso del cadmio y la edad existe una asociación inversa (ji²= 5.9012, pObjective. To determine the concentration of lead (Pb, cadmium (Cd, and chromium (Cr and establish the possible association of these heavy metals with some sociodemographic factors. Material and methods. A representative sample of one hundred dental students from the National Autonomous University of Mexico living in Mexico City participated in this study. Unstimulated human whole saliva samples were analyzed by Atomic Absorption Spectroscopy. Results. Concentrations of Pb, Cd, and Cr were higher than those reported elsewhere: Pb ( or = 3.10 m g/dL-1; Maximum: 16.8 mu g/dL-1 and Minimum: 0.04 mu g/dL-1, Cd ( or = 0.25 mu g/dL-1; Maximum: 2.04 mu g/dL-1 and Minimum: 0.004 mu g/dL-1 and Cr ( or = 1.43 mu g/dL-1; Maximum: 4.82 mu g/dL-1 and Minimum: 0.05 mu g/dL-1. No association was found between the variables studied (age, sex, geographic area and canned food consumption

  5. 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.

  6. 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

  7. Microalgae for Bioenergy: Key Technology Nodes

    Science.gov (United States)

    Kastanek, Frantisek; Rouskova, Milena; Matejkova, Martina; Kastanek, Petr

    2015-01-01

    Microalgae have increasingly gained research interest as a source of lipids for biodiesel production. The wet way processing of harvested microalgae was suggested and evaluated with respect to the possible environmental impacts and production costs. This study is focused on the three key steps of the suggested process: flocculation, water recycling, and extraction of lipids. Microalgae strains with high content of lipids were chosen for cultivation and subsequent treatment process. Ammonium hydroxide was tested as the flocculation agent and its efficiency was compared with chitosan. Determined optimal flocculation conditions for ammonium hydroxide enable the water recycling for the recurring microalgae growth, which was verified for the use of 30, 50, and 80% recycled water. For extraction of the wet microalgae hexane, hexane/ethanol and comparative chloroform/methanol systems were applied. The efficiency of hexane/ethanol extraction system was found as comparable with chloroform/methanol system and it seems to be promising owing to its low volatility and toxicity and mainly the low cost. PMID:26000336

  8. Microalgae for Bioenergy: Key Technology Nodes

    Directory of Open Access Journals (Sweden)

    Ywetta Maleterova

    2015-01-01

    Full Text Available Microalgae have increasingly gained research interest as a source of lipids for biodiesel production. The wet way processing of harvested microalgae was suggested and evaluated with respect to the possible environmental impacts and production costs. This study is focused on the three key steps of the suggested process: flocculation, water recycling, and extraction of lipids. Microalgae strains with high content of lipids were chosen for cultivation and subsequent treatment process. Ammonium hydroxide was tested as the flocculation agent and its efficiency was compared with chitosan. Determined optimal flocculation conditions for ammonium hydroxide enable the water recycling for the recurring microalgae growth, which was verified for the use of 30, 50, and 80% recycled water. For extraction of the wet microalgae hexane, hexane/ethanol and comparative chloroform/methanol systems were applied. The efficiency of hexane/ethanol extraction system was found as comparable with chloroform/methanol system and it seems to be promising owing to its low volatility and toxicity and mainly the low cost.

  9. An Overview of Biocement Production from Microalgae

    Directory of Open Access Journals (Sweden)

    Dessy Ariyanti

    2011-12-01

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

  10. Harvesting of microalgae biomass from the phycoremediation process of greywater.

    Science.gov (United States)

    Atiku, Hauwa; Mohamed, Rmsr; Al-Gheethi, A A; Wurochekke, A A; Kassim, Amir Hashim M

    2016-12-01

    The wide application of microalgae in the field of wastewater treatment and bioenergy source has improved research studies in the past years. Microalgae represent a good source of biomass and bio-products which are used in different medical and industrial activities, among them the production of high-valued products and biofuels. The present review focused on greywater treatment through the application of phycoremediation technique with microalgae and presented recent advances in technologies used for harvesting the microalgae biomass. The advantages and disadvantages of each method are discussed. The microbiological aspects of production, harvesting and utilization of microalgae biomass are viewed.

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

    Science.gov (United States)

    Wang, Jinghan; Yang, Haizhen; Wang, Feng

    2014-04-01

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

  12. 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.

  13. Microalgae: a novel ingredient in nutrition.

    Science.gov (United States)

    Christaki, Efterpi; Florou-Paneri, Panagiota; Bonos, Eleftherios

    2011-12-01

    Microalgae are known for centuries, but their commercial large-scale production started a few decades ago. They can be grown in open-culture systems such as lakes or highly controlled close-culture systems, have higher productivity than the traditional crops and can be grown in climatic conditions and regions where other crops cannot be grown, such as desert and coastal areas. The edible microalgae are the green algae (chlorophyta) and the cyanobacteria. Microalgae contain substances of high biological value, such as polyunsaturated fatty acids, proteins, amino acids, pigments, antioxidants, vitamins and minerals. They are promising sources for novel products and applications and they can be used in the diet of humans and animals as natural foods with health benefits. Moreover, they can find use in the protection of the environment, as well as in pharmaceuticals, biofuel production and cosmetics.

  14. Efectos tóxicos de los metales sobre la actividad microbiana del sistema de lodos activos

    OpenAIRE

    Coello Oviedo, Ma. Dolores; Sales Márquez, Diego; Quiroga Alonso, José María

    2002-01-01

    En este trabajo se estudian los efectos tóxicos que los metales cadmio, cinc y cobre, tienen sobre la actividad microbiana del sistema de lodos activos. Los metales se adicionan al sistema diluidos en un agua residual sintética cuya DQO es de 520 mgO2/L y el ensayo se llevó a cabo durante un tiempo de 8 días. La toxicidad de estos metales se ha determinado a partir de la reducción que experimentan las medidas de actividad tales como la tasa específica de respiración y el porcentaje de células...

  15. Global evaluation of biofuel potential from microalgae.

    Science.gov (United States)

    Moody, Jeffrey W; McGinty, Christopher M; Quinn, Jason C

    2014-06-10

    In the current literature, the life cycle, technoeconomic, and resource assessments of microalgae-based biofuel production systems have relied on growth models extrapolated from laboratory-scale data, leading to a large uncertainty in results. This type of simplistic growth modeling overestimates productivity potential and fails to incorporate biological effects, geographical location, or cultivation architecture. This study uses a large-scale, validated, outdoor photobioreactor microalgae growth model based on 21 reactor- and species-specific inputs to model the growth of Nannochloropsis. This model accurately accounts for biological effects such as nutrient uptake, respiration, and temperature and uses hourly historical meteorological data to determine the current global productivity potential. Global maps of the current near-term microalgae lipid and biomass productivity were generated based on the results of annual simulations at 4,388 global locations. Maximum annual average lipid yields between 24 and 27 m(3)·ha(-1)·y(-1), corresponding to biomass yields of 13 to 15 g·m(-2)·d(-1), are possible in Australia, Brazil, Colombia, Egypt, Ethiopia, India, Kenya, and Saudi Arabia. The microalgae lipid productivity results of this study were integrated with geography-specific fuel consumption and land availability data to perform a scalability assessment. Results highlight the promising potential of microalgae-based biofuels compared with traditional terrestrial feedstocks. When water, nutrients, and CO2 are not limiting, many regions can potentially meet significant fractions of their transportation fuel requirements through microalgae production, without land resource restriction. Discussion focuses on sensitivity of monthly variability in lipid production compared with annual average yields, effects of temperature on productivity, and a comparison of results with previous published modeling assumptions.

  16. Global evaluation of biofuel potential from microalgae

    Science.gov (United States)

    Moody, Jeffrey W.; McGinty, Christopher M.; Quinn, Jason C.

    2014-01-01

    In the current literature, the life cycle, technoeconomic, and resource assessments of microalgae-based biofuel production systems have relied on growth models extrapolated from laboratory-scale data, leading to a large uncertainty in results. This type of simplistic growth modeling overestimates productivity potential and fails to incorporate biological effects, geographical location, or cultivation architecture. This study uses a large-scale, validated, outdoor photobioreactor microalgae growth model based on 21 reactor- and species-specific inputs to model the growth of Nannochloropsis. This model accurately accounts for biological effects such as nutrient uptake, respiration, and temperature and uses hourly historical meteorological data to determine the current global productivity potential. Global maps of the current near-term microalgae lipid and biomass productivity were generated based on the results of annual simulations at 4,388 global locations. Maximum annual average lipid yields between 24 and 27 m3·ha−1·y−1, corresponding to biomass yields of 13 to 15 g·m−2·d−1, are possible in Australia, Brazil, Colombia, Egypt, Ethiopia, India, Kenya, and Saudi Arabia. The microalgae lipid productivity results of this study were integrated with geography-specific fuel consumption and land availability data to perform a scalability assessment. Results highlight the promising potential of microalgae-based biofuels compared with traditional terrestrial feedstocks. When water, nutrients, and CO2 are not limiting, many regions can potentially meet significant fractions of their transportation fuel requirements through microalgae production, without land resource restriction. Discussion focuses on sensitivity of monthly variability in lipid production compared with annual average yields, effects of temperature on productivity, and a comparison of results with previous published modeling assumptions. PMID:24912176

  17. 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...

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

    Science.gov (United States)

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

    2017-03-01

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

  19. Dinámica del cadmio en suelos cultivados con papa en Nariño, Colombia. Dinamic of the cadmium in soils cultivated with potatoes in Nariño, Colombia

    Directory of Open Access Journals (Sweden)

    Liliana Insuasty B

    2008-01-01

    Full Text Available Se evaluó la fijación y movilidad de cadmio en suelos dedicados al cultivo de papa en Túquerres, Pasto y Guachucal. Se tomaron muestras de suelos no disturbadas en cilindros de PVC, las cuales, luego de aplicaciones fraccionadas de cadmio con dosis de 0, 50,100 y 150 ppm, se incubaron a capacidad de campo durante cuatro meses. En estos suelos los contenidos de cadmio total e intercambiable no sobrepasaron los límites permisibles establecidos por Organización Mundial de la Salud-Organización de las Naciones Unidas para la Agricultura y la Alimentación (OMS-FAO; no obstante, la mayor cantidad del elemento se localizó en la parte superior de los núcleos, lo cual indica baja movilidad del elemento en el perfil.The mobility of cadmium and fixation in soils cropped with potatoes in Túquerres, Pasto and Guachucal Nariño, Colombia was evaluated. Samples with an auger of 11 cm diameter and 40 cm in length were taken. On these soil samples applications of 0, 50, 100 and 150 ppm cadmium were, and incubated during a 4 month period under field capacity. In this soils the content of total exchangeable cadmium do not overcome the permissible limits established by World Health Organization-Food and Agriculture Organization of the United Nations. The highest concentration of cadmium applied in the for of total Cd and changeable Cd was found in the higher third part of cores, which indicates a low mobility of the element in the soil profile.

  20. Dinamic of the cadmium in soils cultivated with potatoes in Nariño, Colombia Dinámica del cadmio en suelos cultivados con papa en Nariño, Colombia.

    Directory of Open Access Journals (Sweden)

    Burbano Orjuela Hernán

    2008-03-01

    Full Text Available The mobility of cadmium and fixation in soils cropped with potatoes in Túquerres, Pasto and Guachucal Nariño, Colombia was evaluated. Samples with an auger of 11 cm diameter and 40 cm in length were taken. On these soil samples applications of 0, 50, 100 and 150 ppm cadmium were, and incubated during a 4 month period under field capacity. In this soils the content of total exchangeable cadmium do not overcome the permissible limits established by World Health Organization–Food and Agriculture Organization of the United Nations. The highest concentration of cadmium applied in the for of total Cd and changeable Cd was found in the higher third part of cores, which indicates a low mobility of the element in the soil profile.Se evaluó la fijación y movilidad de cadmio en suelos dedicados al cultivo de papa en Túquerres, Pasto y Guachucal. Se tomaron muestras de suelos no disturbadas en cilindros de PVC, las cuales, luego de aplicaciones fraccionadas de cadmio con dosis de 0, 50,100 y 150 ppm, se incubaron a capacidad de campo durante cuatro meses. En estos suelos los contenidos de cadmio total e intercambiable no sobrepasaron los límites permisibles establecidos por Organización Mundial de la Salud–Organización de las Naciones Unidas para la Agricultura y la Alimentación (OMS–FAO; no obstante, la mayor cantidad del elemento se localizó en la parte superior de los núcleos, lo cual indica baja movilidad del elemento en el perfil.

  1. Temporal trending of lead and cadmium contamination in the Vigo estuary intertidal area Evolución temporal de la contaminación por plomo y cadmio en la zona intermareal de la ría de Vigo

    Directory of Open Access Journals (Sweden)

    J. Alonso Díaz

    2004-12-01

    Full Text Available At the present work, limpet (Patella vulgata L. and seaweed (Ulva lactuca specimens have been monthly sampled at the same point from the Vigo estuary, during a year. Heavy metal (cadmium and lead content has been determined by means of differential pulse anodic stripping voltammetry in both limpet and seaweed tissues, as well as in seawater. The obtained results have shown the main heavy metal content in limpet soft tissues with respect to shell, with maximum concentrations of 3 ppm (limpet shell for lead, whereas the highest content for cadmium was identified in seaweed samples (1.1 ppm. The statistical study revealed the existence of a clear correlation between cadmium and lead concentrations in seaweed samples.En el presente trabajo se han recogido muestras de lapa (Patella vulgata L. y alga verde (Ulva lactuca en un mismo punto de muestreo de la ría de Vigo, con una periodicidad mensual, a lo largo de un año, analizándose por medio de voltamperometría de redisolución anódica la concentración en dos metales pesados con claras repercusiones toxicológicas, cadmio y plomo, en estas muestras, así como en el agua marina. Los resultados obtenidos mostraron la mayor concentración de ambos metales en los tejidos blandos de las lapas frente a las valvas de estos moluscos, con valores máximos en el caso del plomo próximos a 3 ppm (valva de lapa, mientras que para el cadmio se situó en torno a 1,1 ppm (alga verde. El estudio estadístico permitió poner en evidencia una clara correlación estadística entre los valores de cadmio y plomo cuantificados en las muestras de algas.

  2. Efecto de la calidad de la materia orgánica asociada con el uso y manejo de suelos en la retención de cadmio en sistemas altoandinos de colombia

    OpenAIRE

    Isabel del Socorro Bravo Realpe; Camilo Andrés Arboleda Pardo; Francisco José Martín Peinado

    2014-01-01

    El cadmio (Cd) proveniente de suelos afectados por intemperismo y actividades antropogénicas puede producir efectos tóxicos, asociados con la baja afinidad de las formas adsorbentes, la alta solubilidad y la movilidad. Es de gran importancia conocer los fenómenos de adsorción y los factores de movilidad de este elemento y predecir su posible toxicidad en suelos de la región altoandina de Colombia cuyo sistema de uso está cambiando a pasturas y cultivos con aplicación de fertilizantes fosfatad...

  3. hydroprocessing processing processing microalgae derived h

    African Journals Online (AJOL)

    eobe

    Hydrothermal Gasification. Bachelor Degree Thesis,. Chemical Engineering Department, University of. Arizona. [28] Fortier, Marie-Odile P.; Roberts, Griffin W.; Stagg-. Williams, Susan M.; Sturm, Belinda S.M. (2014) Life cycle assessment of bio-jet fuel from hydrothermal liquefaction of microalgae, Appl.Energy, Vol. 122,.

  4. Hydrothermal Liquefaction of the Microalgae Phaeodactylum tricornutum

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  5. 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.

  6. 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

  7. 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

  8. Scenario evaluation of open pond microalgae production

    NARCIS (Netherlands)

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

    2013-01-01

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

  9. 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

  10. Microalgae growth on concentrated human urine

    NARCIS (Netherlands)

    Tuantet, K.; Janssen, M.G.J.; Temmink, H.; Zeeman, G.; Wijffels, R.H.; Buisman, C.J.N.

    2014-01-01

    In this study, for the first time, a microalga was grown on non-diluted human urine. The essential growth requirements for the species Chlorella sorokiniana were determined for different types of human urine (fresh, hydrolysed, male and female). Batch experimental results using microtiter plates

  11. Hydroprocessing Microalgae Derived Hydrothermal Liquefaction Bio ...

    African Journals Online (AJOL)

    Bio-crude, a biomass derived oil similar to petroleum crude in properties, can be produced from microalgae via hydrothermal liquefaction (HTL) and upgraded to ... for hydroprocessing the bio-crude; the products obtainable, their compositions & properties; as well as the inputs required for modelling and simulation of the ...

  12. 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.

  13. Secondary wastewater treatment by microalgae isolated from ...

    African Journals Online (AJOL)

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

  14. 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

    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

  15. 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.

  16. 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

  17. 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.

  18. Valoración del riesgo en salud en un grupo de población de Cali, Colombia, por exposición a plomo, cadmio, mercurio, ácido 2,4-diclorofenoxiacético y diuron, asociada al consumo de agua potable y alimentos

    National Research Council Canada - National Science Library

    Ghisliane Echeverry; Andrés Mauricio Zapata; Martha Isabel Paéz; Fabián Méndez; Miguel Peña

    2015-01-01

    ... a la exposición a cadmio, plomo y mercurio, y a los plaguicidas ácido 2,4-diclorofenoxiacético y diuron, debida al consumo de agua potable y alimentos en un grupo de población de Cali. Materiales y métodos...

  19. 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

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

    Science.gov (United States)

    Navarro, Francisco; Forján, Eduardo; Vázquez, María; Montero, Zaida; Bermejo, Elisabeth; Castaño, Miguel Ángel; Toimil, Alberto; Chagüaceda, Enrique; García-Sevillano, Miguel Ángel; Sánchez, Marisa; Domínguez, María José; Pásaro, Rosario; Garbayo, Inés; Vílchez, Carlos; Vega, José María

    2016-01-01

    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 effect in animals

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

    National Research Council Canada - National Science Library

    Casal, C; Cuaresma, M; Vega, J.M; Vilchez, C

    .... 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...

  2. Relationship between microalgae lipid extracts composition and rheological properties

    OpenAIRE

    AUDO, Mariane; Chailleux, Emmanuel; BUJOLI, B; QUEFFELEC, C; LEGRAND, J; LEPINE, O

    2012-01-01

    Renewable energy sources are developed worldwide due to high oil prices and to limit greenhouse gas emissions. In this context, some groups have focused their work on vegetable oils, and particularly, on microalgae. The last decade has seen an increasing scientific interest in the extraction of lipids from microalgae for the production of biodiesel. Microalgae present main advantages, compared to other energy crops including a high growth rate, a high biomass production, and do not compete...

  3. Tolerancia a la anoxia y defensas antioxidantes en el mejillón verde Perna viridis (Linneus, 1758 bajo exposición aguda al cadmio

    Directory of Open Access Journals (Sweden)

    Edgar Zapata-Vívenes

    2014-07-01

    Full Text Available Se estimó la sobrevivencia a la anoxia del mejillón verde Perna viridis después de siete días de exposición a 50 μg L-1 de cadmio (Cd, seguido de un período de recuperación en el mar durante 21 días. En la glándula digestiva de los organismos experimentales se determinó los niveles de Cd acumulados, y marcadores de estrés oxidativo tales como: metalotioneínas (MT, glutatión reducido (GSH, peroxidación lipídica (TBARS y las actividades de las enzimas catalasa (CAT, glutatión reductasa (GR y glutatión-S-transferasa (GST. Los organismos expuestos a Cd mostraron una menor tolerancia al tratamiento anóxico, sin embargo una vez recuperados en el mar presentaron valores de sobrevivencia relativamente mayores en comparación a sus controles. Los organismos expuestos a Cd revelaron un incremento en la concentración de MT y la actividad de CAT, correlacionado al ingreso corporal de Cd. Los organismos transplantados al mar mostraron una disminución del metal acumulado, manteniendo niveles de MT incrementados. Los mejillones tratados y controles no exhibieron diferencias significativas en los marcadores de estrés oxidativo determinados (TBARS, GSH, GR y GST. El Cd acumulado posiblemente afectó algunas estrategias bioquímicas relacionadas con la tolerancia a la anoxia de P. viridis. Sin embargo, los altos niveles de MT en organismos pre-expuestos y posteriormente recuperados, podría condicionar la protección contra la toxicidad del Cd e indirectamente una mayor tolerancia a la anoxia.

  4. Nutritional evaluation of Australian microalgae as potential human health supplements

    National Research Council Canada - National Science Library

    Kent, Megan; Welladsen, Heather M; Mangott, Arnold; Li, Yan

    2015-01-01

    .... The Australian native microalgae exhibited similar, and in several cases superior, organic nutritional properties relative to the assessed commercial products, with biochemical profiles rich in high...

  5. Removal of freshwater microalgae by a magnetic separation method

    Science.gov (United States)

    Vergini, Sofia S.; Aravantinou, Andriana F.; Manariotis, Ioannis D.

    2013-04-01

    Some species of microalgae, with high growth rate and high lipid content, appear to be attractive alternatives as a feedstock for biodiesel production. The high-energy input for harvesting biomass and removing the water from the algae makes current commercial microalgal biodiesel production cost expensive. The major techniques currently employed in microalgae harvesting and recovery include centrifugation, coagulation-flocculation, bio-flocculation, filtration and screening, gravity sedimentation, and flotation. The purpose of this study was to investigate the harvesting of microalgae cells by coagulation using magnetic activated carbon, magnetite (FeO4) nanoparticles, and common chemical coagulants. Scenedesmus rubescens was selected and cultivated in 10 L flasks under continuous artificial light. Samples were taken at different operation intervals. Jar tests were conducted to investigate the effect of adsorption of microalgae on the magnetic material. The removal efficiency of microalgae was affected by the coagulants dose, stirring time and speed, and the initial microalgae concentration. The recovery of microalgae was greater in cultures with high initial microalgae concentration compared to cultures with low microalgae concentrations.

  6. 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.

  7. 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.

  8. Overcoming Microalgae Harvesting Barrier by Activated Algae Granules.

    Science.gov (United States)

    Tiron, Olga; Bumbac, Costel; Manea, Elena; Stefanescu, Mihai; Nita Lazar, Mihai

    2017-07-05

    The economic factor of the microalgae harvesting step acts as a barrier to scaling up microalgae-based technology designed for wastewater treatment. In view of that, this study presents an alternative microalgae-bacteria system, which is proposed for eliminating the economic obstacle. Instead of the microalgae-bacteria (activated algae) flocs, the study aimed to develop activated algae granules comprising the microalgae Chlorella sp. as a target species. The presence of the filamentous microalgae (Phormidium sp.) was necessary for the occurrence of the granulation processes. A progressive decrease in frequency of the free Chlorella sp. cells was achieved once with the development of the activated algae granules as a result of the target microalgae being captured in the dense and tangled network of filaments. The mature activated algae granules ranged between 600 and 2,000 µm, and were characterized by a compact structure and significant settling ability (21.6 ± 0.9 m/h). In relation to the main aim of this study, a microalgae recovery efficiency of higher than 99% was achieved only by fast sedimentation of the granules; this performance highlighted the viability of the granular activated algae system for sustaining a microalgae harvesting procedure with neither cost nor energy inputs.

  9. An evaluation of the accumulation of intracellular inorganic nitrogen pools by marine microalgae in batch cultures

    Directory of Open Access Journals (Sweden)

    Paris L. Lavín

    2005-06-01

    Full Text Available Methods of extraction, changes in concentrations with growth, and effects of culture conditions on intracellular inorganic nitrogen pools (IIN - ammonia, nitrite, and nitrate were studied in nine species of marine microalgae in batch cultures. The microalgae were analysed to compare three methods of extraction of IIN, one of them developed in this study. The extraction of IIN occurs efficient by with all three methods for four out of the nine species tested. However, for five species significant differences were found among the methods, the best results being obtained with the new method. Microalgae accumulate inorganic forms of nitrogen in different proportions. The species show higher concentrations of either ammonia or nitrate, and always lower concentrations of nitrite. Microalgae of smaller cellular volumes tend to attain higher values of IIN per cubic micrometer (the converse in large-volume species, with some exceptions (Amphidinium carterae and Nannochloropsis oculata. The use of aeration in the cultures determines a decrease in the concentrations of IIN, favours nitrogen assimilation, and generates an increase in growth rates and C:N ratio. High concentrations of IIN are characteristic of the exponential growth phase, but in some cases their occurrence may result from carbon deficiency.Métodos de extração, mudanças na concentração durante o crescimento e efeitos de condições de cultivo sobre conteúdos de nitrogênio inorgânico intracelular (NII - amônia, nitrito e nitrato foram estudados em nove espécies de microalgas marinhas em cultivos estanques. As microalgas foram analisadas para comparar três métodos de extração de NII, um dos quais desenvolvido neste estudo. A extração de NII ocorre de forma eficiente com os três métodos para quatro espécies. Contudo, para cinco espécies diferenças significativas foram encontradas e os melhores resultados foram obtidos com o método novo. As microalgas acumulam formas inorg

  10. Microalgae for Biofuels and Animal Feeds

    Directory of Open Access Journals (Sweden)

    John Benemann

    2013-11-01

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

  11. 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.

  12. Microalgae: cultivation techniques and wastewater phycoremediation.

    Science.gov (United States)

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

    2015-01-01

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

  13. Engineering challenges in biodiesel production from microalgae.

    Science.gov (United States)

    Aguirre, Ana-Maria; Bassi, Amarjeet; Saxena, Priyanka

    2013-09-01

    In recent years, the not too distant exhaustion of fossil fuels is becoming apparent. Apart from this, the combustion of fossil fuels leads to environmental concerns, the emission of greenhouse gases and issues with global warming and health problems. Production of biodiesel from microalgae may represent an attractive solution to the above mentioned problems, and can offer a renewable source of fuel with fewer pollutants. This review presents a compilation of engineering challenges related to microalgae as a source of biodiesel. Advantages and current limitations for biodiesel production are discussed; some aspects of algae cells biology, with emphasis on cell wall composition, as it represents a barrier for fatty acid extraction and lipid droplets are also presented. In addition, recent advances in the different stages of the manufacturing process are included, starting from the strain selection and finishing in the processing of fatty acids into biodiesel.

  14. 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...... was lowered to a sub-optimal level diatoms proliferated in the PBR cultivating the mixed green microalgal consortium. Once the ratio was increased again, the diatoms could be washed out of the system. Model predictive accuracy deteriorated as a result of the changes in culture composition due to the possible...

  15. Lipid extraction from microalgae for biodiesel production

    OpenAIRE

    Halim, Ronald

    2017-01-01

    Microalgae appear to be a promising source of biodiesel as they have high photosynthetic rates and can accumulate substantial amount of lipids in their biomass (up to 77% of dry cell mass in some species). Unlike oilseed crops (such as rapeseed, soybean, and corn) which require freshwater and arable land for their cultivation, many of the marine microalgal strains can be cultivated in saltwater on non-arable lands. As such, large-scale microalgal cultivation should pose minimal interfere with...

  16. 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. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  17. Enriching rotifers with "premium" microalgae. Nannochloropsis gaditana.

    Science.gov (United States)

    Ferreira, Martiña; Coutinho, Paula; Seixas, Pedro; Fábregas, Jaime; Otero, Ana

    2009-01-01

    The nutritive quality of Nannochloropsis gaditana cultured semicontinuously with different daily renewal rates was tested as a diet for short-term enrichment of the rotifer Brachionus plicatilis. After 24 h, dramatic differences in the survival, dry weight, and biochemical composition of the rotifers depending on the renewal rate of microalgal cultures were observed. Survival after the feeding period increased with increasing renewal rates. Rotifers fed microalgae from low renewal rate, nutrient-deficient cultures showed low dry weight and organic contents very similar to those of the initial rotifers that were starved for 12 h before the start of the feeding period. On the contrary, rotifers fed nutrient-sufficient microalgal cells underwent up to twofold increases of dry weight and protein, lipid, and carbohydrate contents with regard to rotifers fed nutrient-depleted N. gaditana. Consequently, feed conversion rate decreased in these conditions, indicating a better assimilation of the microalgal biomass obtained at high renewal rates. No single microalgal biochemical parameter among those studied can explain the response of the filter feeder. Similarly to gross composition, EPA and n-3 contents in rotifers fed microalgae from nutrient-sufficient cultures were double than the contents found in rotifers fed nutrient-limited microalgae. In addition, very high positive correlations between the contents of EPA and n-3 in N. gaditana and B. plicatilis were observed. These results demonstrate that selecting the appropriate conditions of semicontinuous culture can strongly enhance the nutritional value of microalgae that is reflected in the growth and biochemical composition of the filter-feeder even in short exposure periods.

  18. Closing Domestic Nutrient Cycles Using Microalgae.

    Science.gov (United States)

    Vasconcelos Fernandes, Tânia; Shrestha, Rabin; Sui, Yixing; Papini, Gustavo; Zeeman, Grietje; Vet, Louise E M; Wijffels, Rene H; Lamers, Packo

    2015-10-20

    This study demonstrates that microalgae can effectively recover all P and N from anaerobically treated black water (toilet wastewater). Thus, enabling the removal of nutrients from the black water and the generation of a valuable algae product in one step. Screening experiments with green microalgae and cyanobacteria showed that all tested green microalgae species successfully grew on anaerobically treated black water. In a subsequent controlled experiment in flat-panel photobioreactors, Chlorella sorokiniana was able to remove 100% of the phosphorus and nitrogen from the medium. Phosphorus was depleted within 4 days while nitrogen took 12 days to reach depletion. The phosphorus and nitrogen removal rates during the initial linear growth phase were 17 and 122 mg·L(-1)·d(-1), respectively. After this initial phase, the phosphorus was depleted. The nitrogen removal rate continued to decrease in the second phase, resulting in an overall removal rate of 80 mg·L(-1)·d(-1). The biomass concentration at the end of the experiment was 11.5 g·L(-1), with a P content of approximately 1% and a N content of 7.6%. This high algal biomass concentration, together with a relatively short P recovery time, is a promising finding for future post-treatment of black water while gaining valuable algal biomass for further application.

  19. Evaluation on Microalgae Biomass for Bioethanol Production

    Science.gov (United States)

    Chng, L. M.; Lee, K. T.; Chan, D. C. J.

    2017-06-01

    The depletion of energy resources has triggered worldwide concern for alternative sources, especially renewable energy. Microalgae biomass offers the most promising feedstock for renewable energy because of their impressive efficient growing characteristics and valuable composition. Simple cell structure of the microalgae would simplify the pretreatment technology thus increase the cost-effectiveness of biofuel production. Scenedesmus dimorphus is a carbohydrate-rich microalgae that has potential as biomass for bioethanol. The cultivation of Scenedesmus dimorphus under aeration of carbon dioxide enriched air resulted 1.47 g/L of dry biomass with composition of 12 w/w total lipid, 53.7 w/w carbohydrate and 17.4 protein. Prior to ethanolic fermentation with Saccharomyces cerevisiae, various pre-treatment methods were investigated to release and degrade the complex carbohydrate in cell biomass thus obtaining the maximal amount of digestible sugar for ethanolic yeast. In this study, sulfuric acid was used as hydrolysis agent while amyloglucosidase as enzymatic agent. Dried biomass via hydrothermal acidic hydrolysis yielded sugar which is about 89 of total carbohydrate at reaction temperature of 125 °C and acid concentration of 4 v/v. While combination of organosolv treatment (mixture of methanol and chloroform) with enzymatic hydrolysis yielded comparable amount of sugar with 0.568 g glucose/g treated-biomass. In this study, the significant information in pre-treatment process ensures the sustainability of the biofuel produced.

  20. Microalgae and biofuels: a promising partnership?

    Science.gov (United States)

    Malcata, F Xavier

    2011-11-01

    Microalgae have much higher lipid yields than those of agricultural oleaginosous crops, and they do not compromise arable land. Despite this, current microalga-based processes suffer from several constraints pertaining to the biocatalyst and the bioreactor, which hamper technologically and economically feasible scale-up. Here, we briefly review recent active research and development efforts worldwide, and discuss the most relevant shortcomings of microalgal biofuels. This review goes one step further relative to related studies, because it tackles otherwise scarcely mentioned issues - for example, heterotrophic versus autotrophic metabolism, alkane versus glyceride synthesis, conduction versus bubbling of CO(2), and excretion versus accumulation of lipids. Besides promising solutions that have been hypothesized and arise from multidisciplinary approaches, we also consider less conventional ones. Microalgae and biofuels hold indeed a promising partnership, but a fully competitive technology is not expected to be available before the end of this decade, because the need for one order of magnitude increase in productivity requires development of novel apparatuses and transformed cells. Copyright © 2011. Published by Elsevier Ltd.

  1. Marine Viruses that infect Eukaryotic Microalgae.

    Science.gov (United States)

    Kimura, Kei; Tomaru, Yuji

    2015-01-01

    Marine microalgae, in general, explain large amount of the primary productions on the planet. Their huge biomass through photosynthetic activities is significant to understand the global geochemical cycles. Many researchers are, therefore, focused on studies of marine microalgae, i.e. phytoplankton. Since the first report of high abundance of viruses in the sea at late 1980's, the marine viruses have recognized as an important decreasing factor of its host populations. They seem to be composed of diverse viruses infectious to different organism groups; most of them are considered to be phages infectious to prokaryotes, and viruses infecting microalgae might be ranked in second level. Over the last quarter of a century, the knowledge on marine microalgal viruses has been accumulated in many aspects. Until today, ca. 40 species of marine microalgal viruses have been discovered, including dsDNA, ssDNA, dsRNA and ssRNA viruses. Their features are unique and comprise new ideas and discoveries, indicating that the marine microalgal virus research is still an intriguing unexplored field. In this review, we summarize their basic biology and ecology, and discuss how and what we should research in this area for further progress.

  2. Production of biodiesel from Coelastrella sp. microalgae

    Science.gov (United States)

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

    2017-11-01

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

  3. Medicinal effects of peptides from marine microalgae.

    Science.gov (United States)

    Kim, Se-Kwon; Kang, Kyong-Hwa

    2011-01-01

    Nowadays, there are numerous commercial applications of microalgae, and they have been used to enhance the nutritional value of food and animal feed owing to their chemical composition. They are cultivated as a source of highly nutritional and valuable source. Recently, microalgae have been reported to use as a potent source for food additive, nutraceutical, or pharmaceuticals. According to the criteria of nutritional quality and cost, variety of marine organisms has been investigated for their suitability to be applied in the production of protein hydrolysates in functional foods. Recently, a great deal of interest has been expressed regarding marine-derived bioactive peptides because of their numerous health benefits. In addition, many studies have been reported that marine bioactive peptides can be used as functional foods, nutraceuticals, or pharmaceuticals due to their therapeutic potential in the treatment or prevention of various diseases. Hence, in this chapter, we discussed the importance of marine microalgae in relation to their medicinal value. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. 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.

  5. Freshwater and marine microalgae harvesting with magnetic microparticles

    Science.gov (United States)

    Vergini, Sofia; Aravantinou, Andriana; Manariotis, Ioannis D.

    2014-05-01

    Microalgae are considered to be the most promising new source of biomass and biofuels. The use of microalgae for sustainable biofuel production is important because of the lack of hydrocarbons sources. Many studies have focused on the recovery of microalgae biomass from the growth medium in order to reduce production cost. Alternative technologies, other than conventional methods (i.e. centrifugation, coagulation-flocculation, filtration and screening, gravity sedimentation, and flotation), capable to process large volumes of microalgae cultures at a low cost, are essential for microalgae biomass production. The aim of this study was to investigate the harvesting of microalgae cells using magnetic materials (magnetic activated carbon, magnetite microparticles) compared to common flocculants (FeCl3·6H2O, AlCl3, Al2(SO4)3·18H2O), and gravity sedimentation. Scenedesmus rubescens and Dunaliella tertiolecta were selected as representative for freshwater and marine microalgae, respectively. The cultivation of microalgae was conducted under continuous artificial light, in 10 L and 20 L flasks. Samples were taken at different operation intervals to conduct harvesting studies. Batch experiments were conducted to investigate the effect of sorption of microalgae on the magnetic material. The experimental data in the presence of magnetic material were adequately described by the Langmuir isotherm. Scenedesmus rubescens was better adsorbed and harvested than Dunaliella tertiolecta. Furthermore, the recovery of microalgae biomass was greater in cultures with high cell concentration compared to cultures with low concentrations. The results of the jar-test experiments showed that the AlCl3 was more effective than the other two flocculants tested. Specifically, the harvesting efficiency was up to 99% for both microalgae species. Gravity sedimentation was tested for 1 h in both species, and better sedimentation efficiency was observed with the Scenedesmus rubescens.

  6. 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)

  7. Microalgae-bacteria models evolution: From microalgae steady-state to integrated microalgae-bacteria wastewater treatment models - A comparative review.

    Science.gov (United States)

    Solimeno, Alessandro; García, Joan

    2017-12-31

    The search for environmentally neutral alternative fuels had revived the interest for microalgae-bacteria wastewater treatment systems. The potential achieving of bioproducts from microalgae biomass has also greatly contributed. The reactions that occur in these systems are complex, and the degree of scientific knowledge is still scarce compared to that of conventional bacteria wastewater treatments. Mathematical models offer a great opportunity to study the simultaneous effect of the multiple factors affecting microalgae and bacteria, thus allowing for the prediction of final biomass production, and contributing to the system design optimization in terms of operation and control. During the last decades, numerous models describing microalgae growth have been proposed. However, a lower number of integral models considering microalgae as well as bacteria is available. In this paper, the evolution of microalgae models from simple steady-state models (usually dependent on one factor) to more complex dynamic models (with two or more factors) has been revised. A summary of integrated microalgae-bacteria models has been reviewed, outlining their main features and presenting their processes and value parameters. Eventually, a critical discussion on integrated models has been put forward. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. 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

  9. Sobre caudillos

    Directory of Open Access Journals (Sweden)

    Margarita Garrido

    1988-07-01

    Full Text Available Cuadro ensayos: De la respuesta criolla a los caudillos republicanos. Hispanoamérica 1750- 1850: Ensayos sobre la sociedad y el Estado. John Lynch. Universidad Nacional, Bogotá, 1987.

  10. Suitability of Nigerian Weather Conditions for Cultivation of Microalgae

    African Journals Online (AJOL)

    This work evaluates the suitability of Nigeria weather conditions for cultivation of microalgae species. Meteorological data from different locations were analyzed and compared with optimal conditions for cultivation of various species of microalgae. Average solar radiation in various parts were 1439.9±5µmolm2/s for Jos; ...

  11. Effect of photoacclimation on microalgae mass culture productivity

    NARCIS (Netherlands)

    Mooij, de Tim; Nejad, Zeynab Rajabali; Buren, van Lennard; Wijffels, René H.; Janssen, Marcel

    2017-01-01

    Microalgae are capable of adapting their pigmentation to the light regime to which they are exposed. In high density microalgae cultures exposed to sunlight, the high pigment content leads to oversaturation of the photosystems resulting in increased light energy dissipation at the reactor

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

    DEFF Research Database (Denmark)

    Safafar, Hamed; Jacobsen, Charlotte; Møller, Per

    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...

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

    African Journals Online (AJOL)

    Biogas wastewater is always a problem as a result of its extremely high concentrations of nitrogen and phosphorus, which is the main reason for the eutrophication of the surrounding water. The microalga, Chlorella pyrenoidosa, can utilize the nitrogen and phosphorus in wastewater for its growth. Therefore, the microalga ...

  14. A mathematical model of microalgae growth in cylindrical photobioreactor

    Science.gov (United States)

    Bakeri, Noorhadila Mohd; Jamaian, Siti Suhana

    2017-08-01

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

  15. 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

  16. 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

  17. 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.

  18. Effects of wastewater microalgae harvesting methods on polyhydroxybutyrate production.

    Science.gov (United States)

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

    2014-03-01

    Microalgae have gained considerable attention recently as a sustainable means to produce biofuels and bioproducts. It has previously been demonstrated that single strain microalgae can be harvested and processed through a wet lipid extraction procedure (WLEP). After WLEP processing, acetone, butanol, ethanol, and biodiesel can be produced, and growth of recombinant Escherichia coli can be achieved from the microalgae. This study demonstrates the application of different wastewater microalgae harvesting techniques and processing through WLEP on the production of polyhydroxybutyrate (PHB) by E. coli. The harvesting techniques include: cationic potato starch (CPS), cationic corn starch (CCS), aluminum sulfate, and centrifugation. The microalgae-based media were used to grow E. coli to ∼10(13)CFU/mL and produce approximately 7.8% of dry cell weight as PHB. This study demonstrates the feasibility of harvesting wastewater algae to produce PHB and the potential for bioproduct generation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. From lab to full-scale ultrafiltration in microalgae harvesting

    Science.gov (United States)

    Wenten, I. G.; Steven, S.; Dwiputra, A.; Khoiruddin; Hakim, A. N.

    2017-07-01

    Ponding system is generally used for microalgae cultivation. However, selection of appropriate technology for the harvesting process is challenging due to the low cell density of cultivated microalgae from the ponding system and the large volume of water to be handled. One of the promising technologies for microalgae harvesting is ultrafiltration (UF). In this study, the performance of UF during harvesting of microalgae in a lab- and a full-scale test is investigated. The performances of both scales are compared and analyzed to provide an understanding of several aspects which affect the yield produced from lab and actual conditions. Furthermore, a unique self-standing non-modular UF is introduced in the full-scale test. The non-modular UF exhibits several advantages, such as simple piping and connection, single pump for filtration and backwashing, and smaller footprint. With those advantages, the non-modular UF could be a promising technology for microalgae harvesting in industrial-scale.

  1. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Efeitos da exposição ao pesticida carbofurano em duas espécies de microalgas (Desmodesmus communis e Pediastrum boryanum) e seu potencial de biorremediação

    OpenAIRE

    Luz, Daniéli Saul da

    2014-01-01

    As microalgas são organismos de extrema importância responsáveis pela produção de matéria orgânica e oxigênio nos ambientes aquáticos, portanto, qualquer alteração causada por agrotóxicos na estrutura e/ou função desses organismos podem acarretar graves consequências para a biota. Nesta linha,, os efeitos tóxicos do pesticida carbofurano foram avaliados sobre duas espécies de microalgas da Classe Chlorophyceae, Pediastrum boryanum e Desmodesmus communis, a partir da mensuração ...

  3. Microalgae for Bioenergy; Key Technology Nodes

    Czech Academy of Sciences Publication Activity Database

    Maléterová, Ywetta; Kaštánek, František; Rousková, Milena; Matějková, Martina; Kaštánek, P.; Šolcová, Olga

    2015-01-01

    Roč. 2015, č. 2015 (2015), s. 597618 ISSN 1537-744X R&D Projects: GA MŠk LJ12002 Institutional support: RVO:67985858 Keywords : microalgae * oil production * water recycling Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.219, year: 2013 http://apps.webofknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=14&SID=V2kH1WLyceq9ctvzW8I&page=1&doc=1

  4. Towards Sustainable Production of Biofuels from Microalgae

    Directory of Open Access Journals (Sweden)

    Hans Ragnar Giselrød

    2008-07-01

    Full Text Available Renewable and carbon neutral biofuels are necessary for environmental and economic sustainability. The viability of the first generation biofuels production is however questionable because of the conflict with food supply. Microalgal biofuels are a viable alternative. The oil productivity of many microalgae exceeds the best producing oil crops. This paper aims to analyze and promote integration approaches for sustainable microalgal biofuel production to meet the energy and environmental needs of the society. The emphasis is on hydrothermal liquefaction technology for direct conversion of algal biomass to liquid fuel.

  5. 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

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

    Directory of Open Access Journals (Sweden)

    Angel D González Delgado

    2014-03-01

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

  7. 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.

  8. Allelopathy as a potential strategy to improve microalgae cultivation

    Science.gov (United States)

    2013-01-01

    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. PMID:24499580

  9. MICROALGAE AND CYANOBACTERIA: FOOD FOR THOUGHT(1).

    Science.gov (United States)

    Gantar, Miroslav; Svirčev, Zorica

    2008-04-01

    In non-Western civilizations, cyanobacteria have been part of the human diet for centuries. Today, microalgae and cyanobacteria are either produced in controlled cultivation processes or harvested from the natural habitats and marketed as food supplements around the world. Cyanobacteria produce a vast array of different biologically active compounds, some of which are expected to be used in drug development. The fact that some of the active components from cyanobacteria potentially have anticancer, antimicrobial, antiviral, anti-inflammatory, and other effects is being used for marketing purposes. However, introduction of these products in the form of whole biomass for alimentary purposes raises concerns regarding the potential toxicity and long-term effects on human health. Here, we review data on the use of cyanobacteria and microalgae in human nutrition and searched for available information on legislature that regulates the use of these products. We have found that, although the quality control of these products is most often self-regulated by the manufacturers, different governmental agencies are introducing strict regulations for placing novel products, such as algae and cyanobacteria, on the market. The existing regulations require these products to be tested for the presence of toxins, such as microcystin; however, other, sometimes novel, toxins remain undetected, and their long-term effects on human health remain unknown. © 2008 Phycological Society of America.

  10. 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

  11. 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.

  12. 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.

  13. Pretreatment of microalgae to improve biogas production: a review.

    Science.gov (United States)

    Passos, Fabiana; Uggetti, Enrica; Carrère, Hélène; Ferrer, Ivet

    2014-11-01

    Microalgae have been intensively studied as a source of biomass for replacing conventional fossil fuels in the last decade. The optimization of biomass production, harvesting and downstream processing is necessary for enabling its full-scale application. Regarding biofuels, biogas production is limited by the characteristics of microalgae, in particular the complex cell wall structure of most algae species. Therefore, pretreatment methods have been investigated for microalgae cell wall disruption and biomass solubilization before undergoing anaerobic digestion. This paper summarises the state of the art of different pretreatment techniques used for improving microalgae anaerobic biodegradability. Pretreatments were divided into 4 categories: (i) thermal; (ii) mechanical; (iii) chemical and (iv) biological methods. According to experimental results, all of them are effective at increasing biomass solubilization and methane yield, pretreatment effect being species dependent. Pilot-scale research is still missing and would help evaluating the feasibility of full-scale implementation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Potential biotechnological application of microalgae: a critical review.

    Science.gov (United States)

    Odjadjare, Ejovwokoghene C; Mutanda, Taurai; Olaniran, Ademola O

    2017-02-01

    Microalgae are diverse microorganisms inhabiting a wide range of habitats with only a small fraction being cultivated for human use. Recently, interest in microalgal research has increased in the quest for alternative renewable fuels due to possible depletion of fossil fuels in the near future. However, costly downstream processing has hampered the commercialization of biofuels derived from microalgae. Several value added products of industrial, pharmaceutical and agricultural relevance could be simultaneously derived from microalgae during bioenergy production. Despite these value-added products having the potential to offset the high cost of downstream processing of renewable fuels, their production has not been explored in-depth. This review presents a critical overview of the current state of biotechnological applications of microalgae for human benefit and highlights possible areas for further research and development.

  15. 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.

  16. Fatty acids composition of microalgae Chlorella vulgaris can be ...

    African Journals Online (AJOL)

    Fatty acids composition of microalgae Chlorella vulgaris can be modulated by varying carbon dioxide concentration in outdoor culture. YAM Yusof, JMH Basari, NA Mukti, R Sabuddin, AR Muda, S Sulaiman, S Makpol, WZW Ngah ...

  17. Allelopathy as a potential strategy to improve microalgae cultivation

    National Research Council Canada - National Science Library

    Bacellar Mendes, Leonardo Brantes; Vermelho, Alane Beatriz

    2013-01-01

    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...

  18. Carbon dioxide pressure-induced coagulation of microalgae.

    Science.gov (United States)

    Lee, Roland; Jessop, Philip G; Champagne, Pascale

    2015-12-28

    The move to a low-carbon economy has generated renewed interest in microalgae for the production of biofuels with the potential mutual benefit of wastewater treatment. However, harvesting has been identified as a limiting factor to the economic viability of this process. This paper explores the harvesting of microalgae using high-pressure gas without the addition of coagulants. Coagulation of microalgae under high-pressure gas was found to be an efficient method to separate algae from suspension. The critical coagulation pressures (CCPs) for H(2) and CO(2) were determined to be 6.1 and 6.2 MPa, respectively. The CO(2)-induced decrease in solution pH positively influenced coagulation rates, without appearing to affect the CCP. This approach could be beneficial for the economic removal of microalgae from solution for the production of both biofuels and biomedical compounds without the addition of non-environmentally friendly chemicals. © 2015 The Author(s).

  19. Continuous microalgae recovery using electrolysis with polarity exchange.

    Science.gov (United States)

    Kim, Jungmin; Ryu, Byung-Gon; Kim, Bo-Kyong; Han, Jong-In; Yang, Ji-Won

    2012-05-01

    There is increasing interest in the use of microalgae as a renewable source for the production of fuels and chemicals, but improvements are needed in all steps of this process, including harvesting. A continuous microalgae harvest system was developed based on electrolysis, referred to here as a continuous electrolytic microalgae (CEM) harvest system. This innovative system combines cultivation and harvesting and enables continuous and efficient concentration of microalgae. The electrodes were subject to a polarity exchange (PE) in the middle of the operation to further improve the harvest efficiency. Use of PE, rather than conventional electro-coagulation-flotation (ECF), led to more efficient cell recovery and more uniform recovery over the entire harvest chamber. In addition, PE increased the cell growth rate and the circulated cells remained intact after harvesting. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. 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

  1. 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

  2. Triacylglycerol profiling of marine microalgae by mass spectrometry.

    Science.gov (United States)

    Danielewicz, Megan A; Anderson, Lisa A; Franz, Annaliese K

    2011-11-01

    We present a method for the determination of triacylglycerol (TAG) profiles of oleaginous saltwater microalgae relevant for the production of biofuels, bioactive lipids, and high-value lipid-based chemical precursors. We describe a technique to remove chlorophyll using quick, simple solid phase extraction (SPE) and directly compare the intact TAG composition of four microalgae species (Phaeodactylum tricornutum, Nannochloropsis salina, Nannochloropsis oculata, and Tetraselmis suecica) using MALDI time-of-flight (TOF) mass spectrometry (MS), ESI linear ion trap-orbitrap (LTQ Orbitrap) MS, and ¹H NMR spectroscopy. Direct MS analysis is particularly effective to compare the polyunsaturated fatty acid (PUFA) composition for triacylglycerols because oxidation can often degrade samples upon derivatization. Using these methods, we observed that T. suecica contains significant PUFA levels with respect to other microalgae. This method is applicable for high-throughput MS screening of microalgae TAG profiles and may aid in the commercial development of biofuels.

  3. Microalgae, a Potential Natural Functional Food Source – a Review

    Directory of Open Access Journals (Sweden)

    Villarruel-López Angélica

    2017-12-01

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

  4. Bioflocculation: An alternative strategy for harvesting of microalgae - An overview.

    Science.gov (United States)

    Ummalyma, Sabeela Beevi; Gnansounou, Edgard; Sukumaran, Rajeev K; Sindhu, Raveendran; Pandey, Ashok; Sahoo, Dinabandhu

    2017-10-01

    Microalgae based research has been extensively progressed for the production of value added products and biofuels. Potential application of microalgae for biofuel is recently gained more attention for possibilities of biodiesel and other high value metabolites. However, high cost of production of biomass associated with harvesting technologies is one of the major bottleneck for commercialization of algae based industrial product. Based on the operation economics, harvesting efficiency, technological possibilities, flocculation of algal biomass is a superior method for harvesting microalgae from the growth medium. In this article, latest trends of microalgal cell harvesting through flocculation are reviewed with emphasis on current progress and prospect in environmental friendly bio-based flocculation approach. Bio-flocculation based microalgae harvesting technologies is a promising strategy for low cost microalgal biomass production for various applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Microalgae as healthy ingredients for functional food: a review.

    Science.gov (United States)

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

    2017-08-01

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

  6. Attached cultivation technology of microalgae for efficient biomass feedstock production.

    Science.gov (United States)

    Liu, Tianzhong; Wang, Junfeng; Hu, Qiang; Cheng, Pengfei; Ji, Bei; Liu, Jinli; Chen, Yu; Zhang, Wei; Chen, Xiaoling; Chen, Lin; Gao, Lili; Ji, Chunli; Wang, Hui

    2013-01-01

    The potential of microalgae biofuel has not been realized because of low productivity and high costs associated with the current cultivation systems. In this paper, an attached cultivation method was introduced, in which microalgae cells grew on the surface of vertical artificial supporting material to form algal film. Multiple of the algal films were assembled in an array fashion to dilute solar irradiation to facilitate high photosynthetic efficiency. Results showed that a broad range of microalgae species can grow with this attached method. A biomass productivity of 50-80 g m(-2) d(-1) was obtained outdoors for Scenedesmus obliquus, corresponding to the photosynthetic efficiency of 5.2-8.3% (total solar radiation). This attached method also offers lots of possible advantages over traditional open ponds, such as on water saving, harvesting, contamination controlling and scale-up. The attached cultivation represents a promising technology for economically viable production of microalgae biofuels. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Suitability of Nigerian Weather Conditions for Cultivation of Microalgae

    African Journals Online (AJOL)

    Client

    hydrocarbon synthesizer) are potential sources of energy rich fuels. Some of the primary and secondary metabolic products of microalgae are high value biochemical and pharmaceuticals. (Cress well et al., 1989; Richmond, 1986). This work was done ...

  9. 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.

  10. Analysis of Extraction and Transesterification Conditions for Phaeodactylum Tricornutum Microalgae

    OpenAIRE

    Jose Lius Salgueiro; Ángeles Cancela; Ángel Sánchez; Rocío Maceiras; Leticia Pérez

    2015-01-01

    An increasing global demand for a biologically produced energy source has emerged due to the exhausted usage of non-renewable petroleum-derived fuels. Microalgae are a promising feedstock for biofuels because of their capability to produce lipids. In this paper, two operations for biodiesel production were studied from Phaeodactylum Tricornutum microalgae. This marine diatom shows a big potential to produce biodiesel due to its fast growth and lipid accumulation ability. In this research, fir...

  11. Vibrating membrane filtration as improved technology for microalgae dewatering

    OpenAIRE

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

    2014-01-01

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

  12. Triacylglycerol profiling of marine microalgae by mass spectrometry[S

    OpenAIRE

    Danielewicz, Megan A.; Anderson, Lisa A.; Franz, Annaliese K.

    2011-01-01

    We present a method for the determination of triacylglycerol (TAG) profiles of oleaginous saltwater microalgae relevant for the production of biofuels, bioactive lipids, and high-value lipid-based chemical precursors. We describe a technique to remove chlorophyll using quick, simple solid phase extraction (SPE) and directly compare the intact TAG composition of four microalgae species (Phaeodactylum tricornutum, Nannochloropsis salina, Nannochloropsis oculata, and Tetraselmis suecica) using M...

  13. Harvesting of freshwater microalgae biomass by Scenedesmus sp. as bioflocculant

    Science.gov (United States)

    Rinanti, A.; Purwadi, R.

    2018-01-01

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

  14. Growth of microalgae Scenedesmus sp in ethanol vinasse

    OpenAIRE

    Ramirez, Nelzy Neyza Vargas; Farenzena, Marcelo; Trierweiler, Jorge Otávio

    2014-01-01

    This study evaluated the feasibility of using vinasse as a nutrient source for microalgae cultivation. The Scenedesmus sp was grown in a medium supplemented with vinasse and process variables were optimized using a factorial design and a Central Composite Design (CCD). The factorial design results showed that it was possible to cultivate microalgae at concentrations of up to 40% of vinasse in the culture medium. The CCD results showed that the light intensity and vinasse concentration influen...

  15. 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.

  16. Lipid Accumulation Mechanisms in Auto- and Heterotrophic Microalgae.

    Science.gov (United States)

    Chen, Hao-Hong; Jiang, Jian-Guo

    2017-09-20

    Microalgae lipids have attracted great attention in the world as a result of their potential use for biodiesel productions. Microalgae are cultivated in photoautotrophic conditions in most cases, but several species are able to grow under heterotrophic conditions, in which microalgae are cultivated in the dark where the cell growth and reproduction are supported by organic carbons. This perspective is covering the related studies concerning the difference between hetero- and autotrophic cultivation of microalgae. The auto- and heterotrophic central carbon metabolic pathways in microalgae are described, and the catalyzing reactions of several key metabolic enzymes and their corresponding changes in the protein level are summarized. Under adverse environmental conditions, such as nutrient deprivation, microalgae have the ability to highly store energy by forming triacylglycerol (TAG), the reason for which is analyzed. In addition, the biosynthesis of fatty acids and TAGs and their difference between auto- and heterotrophic conditions are compared at the molecular level. The positive regulatory enzymes, such as glucose transporter protein, fructose-1,6-bisphosphate aldolase, and glycerol-3-phosphate dehydrogenase, and the negative regulation enzymes, such as triose phosphate isomerase, played a crucial role in the lipid accumulation auto- and heterotrophic conditions.

  17. Microalgae as Sustainable Renewable Energy Feedstock for Biofuel Production

    Science.gov (United States)

    Yusoff, Fatimah Md.; Shariff, M.

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-03-01

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

  19. 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.

  20. Variation in lipid extractability by solvent in microalgae. Additional criterion for selecting species and strains for biofuel production from microalgae.

    Science.gov (United States)

    Mendoza, Héctor; Carmona, Laura; Assunção, Patricia; Freijanes, Karen; de la Jara, Adelina; Portillo, Eduardo; Torres, Alicia

    2015-12-01

    The lipid extractability of 14 microalgae species and strains was assessed using organic solvents (methanol and chloroform). The high variability detected indicated the potential for applying this parameter as an additional criterion for microalgae screening in industrial processes such as biofuel production from microalgae. Species without cell walls presented higher extractability than species with cell walls. Analysis of cell integrity by flow cytometry and staining with propidium iodide showed a significant correlation between higher resistance to the physical treatments of cell rupture by sonication and the lipid extractability of the microalgae. The results highlight the cell wall as a determining factor in the inter- and intraspecific variability in lipid extraction treatments. Copyright © 2015. Published by Elsevier Ltd.

  1. Cultivation of microalgae in industrial wastewaters

    DEFF Research Database (Denmark)

    van Wagenen, Jonathan Myerson

    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...... to autotrophic controls. Industrial wastewater was used as cultivation medium of Chlorella sorokiniana. The culture was able to grow at high rates upto a density of 4 g L-1. The deceleration-stat technique was used to create a series of pseudo-steady states to give information about the expected results...... to a growing body of knowledge with the aim to make algae cultivation viable for the production of sustainable products. Specific contributions include: improvement in the methods of screening the growth potential of different microalgae species; identification of an industrial wastewater that allows good...

  2. Optimization of an industrial microalgae fermentation.

    Science.gov (United States)

    Hilaly, A K; Karim, M N; Guyre, D

    1994-02-20

    Optimization of cellular productivity of an industrial microalgae fermentation was investigated. The fermentation was carried out at Coors Biotech Products Company, Fort Collins, Colorado. A mathematical model was developed based on the data collected from pilot plant test runs at different operating conditions. Pontryagin's maximum principle was used for determining the optimal feed policy. A feedback control algorithm was also studied for maximizing the cellular productivity. During continuous operation, the optimum dilution rate was determined by an adaptive optimization scheme based on the steepest descent technique and a recursive least squares estimation of model parameters. A direct search algorithm was also applied to determine the optimum feed rate. Comparison of the theoretical results of the different optimization schemes revealed that the direct search algorithm was preferable because of its simplicity. The experimental results of real time application of the feedback algorithm agreed fairly well with those of the theoretical analyses. (c) 1994 John Wiley & Sons, Inc.

  3. Bacterial influence on alkenones in live microalgae.

    Science.gov (United States)

    Segev, Einat; Castañeda, Isla S; Sikes, Elisabeth L; Vlamakis, Hera; Kolter, Roberto

    2016-02-01

    The microalga Emiliania huxleyi produces alkenone lipids that are important proxies for estimating past sea surface temperatures. Field calibrations of this proxy are robust but highly variable results are obtained in culture. Here, we present results suggesting that algal-bacterial interactions may be responsible for some of this variability. Co-cultures of E. huxleyi and the bacterium Phaeobacter inhibens resulted in a 2.5-fold decrease in algal alkenone-containing lipid bodies. In addition levels of unsaturated alkenones increase in co-cultures. These changes result in an increase in the reconstructed growth temperature of up to 2°C relative to axenic algal cultures. © 2015 Phycological Society of America.

  4. 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

  5. Acclimation of microalgae to wastewater environments involves increased oxidative stress tolerance activity

    National Research Council Canada - National Science Library

    Osundeko, Olumayowa; Dean, Andrew P; Davies, Helena; Pittman, Jon K

    2014-01-01

    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...

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

    National Research Council Canada - National Science Library

    Grossman, Arthur

    2016-01-01

    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...

  7. Choreography of Transcriptomes and Lipidomes of Nannochloropsis Reveals the Mechanisms of Oil Synthesis in Microalgae

    National Research Council Canada - National Science Library

    Jing Li; Danxiang Han; Dongmei Wang; Kang Ning; Jing Jia; Li Wei; Xiaoyan Jing; Shi Huang; Jie Chen; Yantao Li; Qiang Hu; Jian Xu

    2014-01-01

    To reveal the molecular mechanisms of oleaginousness in microalgae, transcriptomic and lipidomic dynamics of the oleaginous microalga Nannochloropsis oceanica IMET1 under nitrogen-replete (N+) and N-depleted (N...

  8. 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

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

    Directory of Open Access Journals (Sweden)

    Vera Lucia Mota Klein

    2006-04-01

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

  10. Microalgae as human food: chemical and nutritional characteristics of the thermo-acidophilic microalga Galdieria sulphuraria.

    Science.gov (United States)

    Graziani, Giulia; Schiavo, Simona; Nicolai, Maria Adalgisa; Buono, Silvia; Fogliano, Vincenzo; Pinto, Gabriele; Pollio, Antonino

    2013-01-01

    The use of microalgae as a food source is still poorly developed because of the technical difficulties related to their cultivation and the limited knowledge about their chemical composition and nutritional value. The unicellular red microalga Galdieria sulphuraria has a very high daily productivity and its cultivation under acidic conditions avoided any bacterial contamination. G. sulphuraria can be cultured under autotrophic and heterotrophic conditions: in this study a screening of 43 strains showed that in the latter case a duplication of biomass production was obtained. The proximate composition (protein, carbohydrates, fiber and lipids), the micronutrient content (carotenoids, phycobiliproteins, chlorophylls and vitamins) together with the antioxidant activity of the biomass produced by a selected strain of G. sulphuraria under both cultivation conditions were determined. Results showed that the material is rich in proteins (26-32%) and polysaccharides (63-69%) and poor in lipids. Under heterotrophic cultivation conditions, the lipid moiety mainly contained monounsaturated fatty acids. Among micronutrients, some B group vitamins are present, beta-carotene is the main carotenoid and phycobiliproteins are present under both cultivating conditions. G. sulphuraria proteins are strictly associated with polysaccharide components and therefore not digestible. In the second part of the work, an extraction protocol using Viscozyme L, a commercial enzymatic preparation containing a mixture of polysaccharidases, was developed which made G. sulphuraria proteins a good substrate for human gastrointestinal enzymes. All in all, the data suggested that G. sulphuraria biomass has a potential use as food ingredients both for protein-rich or insoluble dietary fibre-rich applications. The low concentration of lipids and the absence of green color make this microalgae source particularly useful for the addition to many food preparations.

  11. 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. 

  12. Determinación de la adsorción de cadmio mediante isotermas de adsorción en suelos agrícolas venezolanos Determination of the adsorption of cadmium by adsorption isotherms in agricultural soils venezuelans

    Directory of Open Access Journals (Sweden)

    Nereida Sánchez

    2011-04-01

    Full Text Available El cadmio es un metal pesado que tiende a acumularse en la superficie del suelo. En los últimos años, las actividades antropogénicas han ocasionado un incremento en los niveles de este metal en suelos agrícolas generando gran preocupación ambiental debido a su movilidad y lixiviación en el perfil del suelo y a la facilidad con que es absorbido por las plantas. El objetivo de este trabajo fue determinar la capacidad de adsorción de cadmio, de cuatro suelos venezolanos de uso agrícola con diferencias texturales. Para determinar la capacidad de adsorción del metal en cada suelo, inicialmente se determinó el tiempo óptimo de agitación; el cual fue de 2 horas y la relación suelo-solución enriquecedora de Cd; la cual fue de 1:50. Con estos parámetros se elaboraron las isotermas de adsorción para los suelos y se compararon los modelos de Freundlich y Langmuir. Los resultados mostraron que el modelo matemático de Freundlich es el que mejor describe la cinética de la reacción y la capacidad de adsorción de Cd por los suelos, siendo los que poseen mayores contenidos de arcilla, MO y pH ácidos los de mayor capacidad de adsorción.Cadmium is a heavy metal which tends to accumulate in the soil surface. In recent years, anthropogenic activities have caused an increase of the levels of this metal in agricultural soils causing great environmental concern due to their mobility and leaching in the soil profile and the ease way to be absorbed by plants. The purpose of this study was to determine the adsorption capacity of cadmium in four Venezuelan agricultural soils with different texture. To determine the adsorption capacity of Cd in each soil, first of all the optimal time of stirring was determined, which was two hours and the soilenriching solution of Cd, which was (1/50. With these parameters, cadmium adsorption isotherms for all soils were developed and compared with Freundlich and Langmuir models. The data showed that the Freundlich

  13. 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

  14. Extracellular Metabolites from Industrial Microalgae and Their Biotechnological Potential.

    Science.gov (United States)

    Liu, Lu; Pohnert, Georg; Wei, Dong

    2016-10-20

    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.

  15. 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.

  16. 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. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. BIOREMOVAL OF LEAD IN INDUSTRIAL WASTEWATER BY MICROALGAE

    Directory of Open Access Journals (Sweden)

    M. RANITHA

    2016-07-01

    Full Text Available The removal of heavy metals from our environment especially wastewater is now shifting from the use of conventional removal method such as chemical precipitation, coagulation and membrane filtration to the use of bioremoval method. The presence of heavy metals in the environment is of major concern because of their toxicity, bioaccumulating tendency, and threat to human life and the environment. In recent years, many low cost sorbents such as microalgae, fungi bacteria and lignocellulosic agricultural by-products have been investigated for their biosorption capacity towards heavy metals. In this project, the focus is on bioremoval of heavy metals in wastewater using marine microalgae. The study will be emphasize on the efficiency of two marine microalgae named Nannochloropsis oculata and Tetraselmis chuii in treating the Lead (Pb content in industrial wasterwater. An experiment on the effect of various Pb concentration (10/20/40/60/80/100mg/L towards the microalgae has been studied. The obtained result showed that the content of chlorophyll-A in the microalgae sample, after 7 days of exposures to Pb, decreased as the Pb concentration increased. Besides that, Tetraselmis chuii was found to be more sensitive compared to Nannochloropsis oculata where both were able to tolerate the Pb concentration of up to only 20mg/L and 60mg/L, respectively.

  18. Microalgae-based biorefinery--from biofuels to natural products.

    Science.gov (United States)

    Yen, Hong-Wei; Hu, I-Chen; Chen, Chun-Yen; Ho, Shih-Hsin; Lee, Duu-Jong; Chang, Jo-Shu

    2013-05-01

    The potential for biodiesel production from microalgal lipids and for CO2 mitigation due to photoautotrophic growth of microalgae have recently been recognized. Microalgae biomass also has other valuable components, including carbohydrates, long chain fatty acids, pigments and proteins. The microalgae-based carbohydrates consist mainly of cellulose and starch without lignin; thus they can be ready carbon source for the fermentation industry. Some microalgae can produce long chain fatty acids (such as DHA and EPA) as valuable health food supplements. In addition, microalgal pigments and proteins have considerable potential for many medical applications. This review article presents comprehensive information on the current state of these commercial applications, as well as the utilization and characteristics of the microalgal components, in addition to the key factors and challenges that should be addressed during the production of these materials, and thus provides a useful report that can aid the development of an efficient microalgae-based biorefinery process. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. 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.

  20. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Low-cost harvesting of microalgae biomass from water

    Directory of Open Access Journals (Sweden)

    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

    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.

  4. 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.

  5. Microalgae as bioreactors for bioplastic production.

    Science.gov (United States)

    Hempel, Franziska; Bozarth, Andrew S; Lindenkamp, Nicole; Klingl, Andreas; Zauner, Stefan; Linne, Uwe; Steinbüchel, Alexander; Maier, Uwe G

    2011-10-17

    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. 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. 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.

  6. 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.

  7. 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.

  8. Safety assessment of the microalgae Nannochloropsis oculata

    Directory of Open Access Journals (Sweden)

    Michael L. Kagan

    2015-01-01

    Full Text Available Nannochloropsis oculata is a marine-water microalgae that is considered to be a good source of omega-3 fatty acids, specifically eicosapentaenoic acid (EPA, utilized in the production of an omega-3 oil for use as a dietary supplement. This study investigates the safety of N. oculata in male and female Sprague-Dawley rats administered a 0 or 10 mL/kg bw/rat N. oculata (10E8 viable cells/mL suspension by oral gavage once daily for 14 consecutive days. No mortalities occurred and no signs of toxicity were observed during the study. No treatment-related effects were seen for body weight, food consumption, urinalysis, clinical chemistry, hematology, gross pathology, organ weights, or histopathology. Although statistically significant effects were noted for some endpoints, none were considered to be of toxicological significance. The N. oculata suspension was concluded to have no toxicity in rats, confirming that the algal strain used in the production of omega-3 oil is not pathogenic when administered orally to rats.

  9. Microalgae harvesting and subsequent biodiesel conversion.

    Science.gov (United States)

    Tran, Dang-Thuan; Le, Bich-Hanh; Lee, Duu-Jong; Chen, Ching-Lung; Wang, Hsiang-Yu; Chang, Jo-Shu

    2013-07-01

    Chlorella vulgaris ESP-31 containing 22.7% lipid was harvested by coagulation (using chitosan and polyaluminium chloride (PACl) as the coagulants) and centrifugation. The harvested ESP-31 was directly employed as the oil source for biodiesel production via transesterification catalyzed by immobilized Burkholderia lipase and by a synthesized solid catalyst (SrO/SiO2). Both enzymatic and chemical transesterification were significantly inhibited in the presence of PACl, while the immobilized lipase worked well with wet chitosan-coagulated ESP-31, giving a high biodiesel conversion of 97.6% w/w oil, which is at a level comparable to that of biodiesel conversion from centrifugation-harvested microalgae (97.1% w/w oil). The immobilized lipase can be repeatedly used for three cycles without significant loss of its activity. The solid catalyst SrO/SiO2 worked well with water-removed centrifuged ESP-31 with a biodiesel conversion of 80% w/w oil, but the conversion became lower (55.7-61.4% w/w oil) when using water-removed chitosan-coagulated ESP-31 as the oil source. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. 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

  11. Growth of microalgae in autotrophic stationary systems

    Directory of Open Access Journals (Sweden)

    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.

  12. Antioxidant activity of the microalga Spirulina maxima

    Directory of Open Access Journals (Sweden)

    Miranda M.S.

    1998-01-01

    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.

  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. Nitrogen Removal from Landfill Leachate by Microalgae

    Directory of Open Access Journals (Sweden)

    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.

  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

    2016-11-17

    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.

  16. Microalgae as bioreactors for bioplastic production

    Directory of Open Access Journals (Sweden)

    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.

  17. Safety assessment of the microalgae Nannochloropsis oculata.

    Science.gov (United States)

    Kagan, Michael L; Matulka, Ray A

    2015-01-01

    Nannochloropsis oculata is a marine-water microalgae that is considered to be a good source of omega-3 fatty acids, specifically eicosapentaenoic acid (EPA), utilized in the production of an omega-3 oil for use as a dietary supplement. This study investigates the safety of N. oculata in male and female Sprague-Dawley rats administered a 0 or 10 mL/kg bw/rat N. oculata (10E8 viable cells/mL) suspension by oral gavage once daily for 14 consecutive days. No mortalities occurred and no signs of toxicity were observed during the study. No treatment-related effects were seen for body weight, food consumption, urinalysis, clinical chemistry, hematology, gross pathology, organ weights, or histopathology. Although statistically significant effects were noted for some endpoints, none were considered to be of toxicological significance. The N. oculata suspension was concluded to have no toxicity in rats, confirming that the algal strain used in the production of omega-3 oil is not pathogenic when administered orally to rats.

  18. 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.

  19. 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.

  20. 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.

  1. Bioelectrochemical systems using microalgae - A concise research update.

    Science.gov (United States)

    Saratale, Rijuta Ganesh; Kuppam, Chandrasekar; Mudhoo, Ackmez; Saratale, Ganesh Dattatraya; Periyasamy, Sivagurunathan; Zhen, Guangyin; Koók, László; Bakonyi, Péter; Nemestóthy, Nándor; Kumar, Gopalakrishnan

    2017-06-01

    Excess consumption of energy by humans is compounded by environmental pollution, the greenhouse effect and climate change impacts. Current developments in the use of algae for bioenergy production offer several advantages. Algal biomass is hence considered a new bio-material which holds the promise to fulfil the rising demand for energy. Microalgae are used in effluents treatment, bioenergy production, high value added products synthesis and CO2 capture. This review summarizes the potential applications of algae in bioelectrochemically mediated oxidation reactions in fully biotic microbial fuel cells for power generation and removal of unwanted nutrients. In addition, this review highlights the recent developments directed towards developing different types of microalgae MFCs. The different process factors affecting the performance of microalgae MFC system and some technological bottlenecks are also addressed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. 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.

  3. Investigation of microalgae growth on electrospun nanofiber mats

    Directory of Open Access Journals (Sweden)

    Christina Großerhode

    2017-08-01

    Full Text Available Due to their large inner surface, nanofiber mats are often used in tissue engineering and examined with respect to cell adhesion, e.g., for cultivation of fibroblasts. The combination of different polymers with a large contact area, however, could also be used for growth of different plants including green microalgae. Here, the cultivation of the microalga Chlamydomonas reinhardtii on different polymer substrates was examined. We investigated growth on two nanofiber mats consisting of polyamide (PA6 and polyacrylonitrile (PAN and a polypropylene (PP microfiber mat as substrates, compared with a pure multi-well plate. It was found that the algae were able to grow on all textile mats without change in morphology, indicating that all polymers were non-toxic to the cells. Thus, these nonwovens might be suitable filters for the separation of microalgae in biotechnological processes.

  4. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. 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

  6. Engineering fatty acid biosynthesis in microalgae for sustainable biodiesel.

    Science.gov (United States)

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

    2013-06-01

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

  7. 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.

  8. 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

    2017-01-22

    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.

  9. 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.

  10. 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.

  11. Cultivation Of Microalgae (Chlorella vulgaris For Biodiesel Production

    Directory of Open Access Journals (Sweden)

    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.

  12. 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.

  13. Interface-Controlled Motility of Photoactive Microalgae in Confinement

    Science.gov (United States)

    Ostapenko, Tanya; Kreis, Christian T.; Baeumchen, Oliver

    The natural habitats of many biological microorganisms include complex interfaces and varying environmental conditions. For flagellated microalgae swimming in an aqueous medium, we showed that the curvature of the compartment wall governs their motility in geometric confinement. This curvature-guided motility results in long detention times towards the interface, which we determined from the analysis of individual cell trajectories. For puller-type microswimmers, the precise nature of their flagella-wall interactions are important. We discovered a way to control these interactions for photoactive microalgae by manipulating the adhesiveness of their flagella in light. Here, we report on the swimming dynamics of single photoactive microalgae in two-dimensional microfluidic chambers under different light conditions. We find that their motility can be switched reversibly in confinement, which could be exploited for use in biological optical traps and wastewater decontamination.

  14. Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

    Science.gov (United States)

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

    2013-01-01

    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. PMID:23344113

  15. 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.

  16. Microalgae as source of biofuel: technology and prospective

    Science.gov (United States)

    Ferraro, Angelo

    2017-12-01

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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. 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.

  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. 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.

  5. 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.

  6. Terpenes as Green Solvents for Extraction of Oil from Microalgae

    Directory of Open Access Journals (Sweden)

    Celine Dejoye Tanzi

    2012-07-01

    Full Text Available Herein is described a green and original alternative procedure for the extraction of oil from microalgae. Extractions were carried out using terpenes obtained from renewable feedstocks as alternative solvents instead of hazardous petroleum solvents such as n-hexane. The described method is achieved in two steps using Soxhlet extraction followed by the elimination of the solvent from the medium using Clevenger distillation in the second step. Oils extracted from microalgae were compared in terms of qualitative and quantitative determination. No significant difference was obtained between each extract, allowing us to conclude that the proposed method is green, clean and efficient.

  7. Novel protocol for lutein extraction from microalga Chlorella vulgaris

    DEFF Research Database (Denmark)

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

    2017-01-01

    Lutein is a pigment generally extracted from marigold flowers. However, lutein is also found in considerable amounts in microalgae. In this study a novel method was developed to improve the extraction efficiency of lutein from microalga C. vulgaris. Differently from conventional methods, ethanol...... purity was increased from 73.6% to 93.7% by decreasing the ethanol-water ratio from 85% to 50% in the resolubilization step. The novel method was also tested with tetrahydrofuran. The extraction proved to be again more effective than the conventional one; however dichloromethane outperformed...

  8. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Effect of Quail Litter Biochar on Productivity of Four New Physic Nut Varieties Planted in Cadmium-Contaminated Soil Efecto del Biocarbón de Cama de Codorniz en la Productividad de Cuatro Variedades Nuevas de Jatrofa Plantadas en Suelo Contaminado con Cadmio

    Directory of Open Access Journals (Sweden)

    Tawadchai Suppadit

    2012-03-01

    Full Text Available Biochar can improve soil structure and water retention, enhance nutrient availability and retention, ameliorate acidity, and reduce heavy metal toxicity to plant roots. In this study, a basin experiment was conducted to investigate the effects of quail litter biochar (QLB on the availability of Cd to physic nut (Jatropha curcas L. plants. QLB was applied to the soil in which four new physic nut varieties (Takfa, Doi Saket, Lao, and Rayong in factorial combinations at four levels (0, 5, 10, and 15 g kg-1 soil to soil that contained 60.8 mg Cd kg-1. After transplanting plant height and canopy radius were measured every 2-mo and the number of leaves and branches at 6-mo, while yield components and Cd residues were measured at 8-mo intervals. The contaminated soil was analyzed for chemical characteristics, nutrients, and Cd residue after the plant harvest. The addition of QLB to soil caused a significant increase in the soil's growth potential and physic nut yield components (P Se ha visto que el biocarbón mejora la estructura del suelo y la retención de agua, mejora la disponibilidad y la retención de nutrientes, controla la acidez y reduce la toxicidad de metales pesados en las raíces de las plantas. En este trabajo se investiga el uso de biocarbón de cama de codorniz (QLB en la disponibilidad de Cd para la planta de jatrofa (Jatropha curcas L. en un estudio de laboratorio. Se realiza una combinación factorial con cuatro variedades nuevas de jatrofa (Takfa, Doi Saket, Lao y Rayong sobre cuatro proporciones de QLB a 0, 5, 10, y 15 g kg-1 añadidos por separado a suelo contaminado con 60,8 mg Cd kg-1. Tras el trasplante se midió la altura de la planta y la cubierta vegetal cada 2 meses, el número de hojas y ramas a los 6 meses y los parámetros de rendimiento así como el residuo de Cd a los 8 meses. A continuación, tras la cosecha de la planta, se analizaron las características químicas, nutrientes y residuo de Cd en el suelo contaminado

  10. Microalgae respond differently to nitrogen availability during culturing

    Indian Academy of Sciences (India)

    2015-04-17

    Apr 17, 2015 ... 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 ...

  11. Prospective of biodiesel production utilizing microalgae as the cell ...

    African Journals Online (AJOL)

    Microalgae are sunlight-driven miniature factories that convert atmospheric CO2 to polar and neutral lipids which after esterification can be utilized as an alternative source of petroleum. Further, other metabolic products such as bioethanol and biohydrogen produced by algal cells are also being considered for the same ...

  12. Micro-algae: the Rise of Next Generation Biofuels

    CSIR Research Space (South Africa)

    Moodley, G

    2015-03-01

    Full Text Available to significant cell titres. They have an inherently faster growth rate in comparison to plant sources and have an ability to accumulate algal lipids up to 70% of its dry cell weight. Research into microalgae as a biodiesel feedstock is being conducted globally...

  13. Response of microalgae from mud-flats to petroleum hydrocarbons ...

    African Journals Online (AJOL)

    Using indigenous microalgae and aeration, there was a reduction in nutrients; NH4 +, NO3 -, PO4 3- and SO4 2-. However, in the presence of the hydrocarbon, there was delayed nutrient uptake. The consequence of this response was the observed reductions in chlorophyll content, biomass, etc. There was however a quick ...

  14. Prospective of biodiesel production utilizing microalgae as the cell ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-08

    Mar 8, 2010 ... Acien Fernandez FG, Fernandez Sevilla JM, Sanchez Perez JA, Molina. Grima E, Chisti Y (2001). Airlift-driven external-loop tubular photobioreactors for outdoor production of microalgae: assessment of design and performance. Chem. Eng. Sci. 56: 2721-2732. Acien Fernandez FG, Hall DO, Canizares ...

  15. Biodiesel Production from Microalgae by Extraction – Transesterification Method

    Directory of Open Access Journals (Sweden)

    Nguyen Thi Phuong Thao

    2013-11-01

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

  16. Lichen microalgae are sensitive to environmental concentrations of atrazine.

    Science.gov (United States)

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

    2017-04-03

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

  17. Edible oils from microalgae: insights in TAG accumulation

    NARCIS (Netherlands)

    Klok, A.J.; Lamers, P.P.; Martens, D.E.; Draaisma, R.B.; Wijffels, R.H.

    2014-01-01

    Microalgae are a promising future source for sustainable edible oils. To make microalgal oil a cost-effective alternative for common vegetable oils, increasing TAG productivity and TAG content are of high importance. Fulfilling these targets requires proper understanding of lipid metabolism in

  18. 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

  19. 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,

  20. 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

  1. Evaluation of the Antioxidant Activity of Cell Extracts from Microalgae

    Directory of Open Access Journals (Sweden)

    F. Xavier Malcata

    2013-04-01

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

  2. Isolation of microalgae species from arid environments and ...

    African Journals Online (AJOL)

    sunny t

    2015-05-06

    May 6, 2015 ... production. Key words: Biodiesel, Chlorella, Chlorococcum, Botyrococcus sp., lipid accumulation, microalgae, Oocystis. INTRODUCTION ... made from sugar, starch, vegetable oil or animal fats using conventional .... Acid value conversion factors for lauric and palmitic were 2.81 and. 2.19, respectively.

  3. 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

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

    Science.gov (United States)

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

    2014-04-01

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

  5. 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.

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

    Science.gov (United States)

    Gong, Yangmin; Jiang, Mulan

    2011-07-01

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

  7. A techno-economic analysis of biodiesel production from microalgae

    NARCIS (Netherlands)

    Olivieri, G.; Guida, T.; Salatino, P.; Marzocchella, A.

    2013-01-01

    The preliminary assessment of a cost-effective flow-sheet for the production of biodiesel from microalgae lipid fraction was carried out. The study was based on approximated cost-estimation methods integrated with the simulation software Aspen Plus (R). Several scenarios were investigated to compare

  8. 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

  9. Analysis of Fatty Acid Content and Composition in Microalgae

    NARCIS (Netherlands)

    Breuer, G.; Evers, W.A.C.; Vree, de J.H.; Kleinegris, D.M.M.; Martens, D.E.; Wijffels, R.H.; Lamers, P.P.

    2013-01-01

    A method to determine the content and composition of total fatty acids present in microalgae is described. Fatty acids are a major constituent of microalgal biomass. These fatty acids can be present in different acyl-lipid classes. Especially the fatty acids present in triacylglycerol (TAG) are of

  10. Current status and perspectives of genome editing technology for microalgae.

    Science.gov (United States)

    Jeon, Seungjib; Lim, Jong-Min; Lee, Hyung-Gwan; Shin, Sung-Eun; Kang, Nam Kyu; Park, Youn-Il; Oh, Hee-Mock; Jeong, Won-Joong; Jeong, Byeong-Ryool; Chang, Yong Keun

    2017-01-01

    Genome editing techniques are critical for manipulating genes not only to investigate their functions in biology but also to improve traits for genetic engineering in biotechnology. Genome editing has been greatly facilitated by engineered nucleases, dubbed molecular scissors, including zinc-finger nuclease (ZFN), TAL effector endonuclease (TALEN) and clustered regularly interspaced palindromic sequences (CRISPR)/Cas9. In particular, CRISPR/Cas9 has revolutionized genome editing fields with its simplicity, efficiency and accuracy compared to previous nucleases. CRISPR/Cas9-induced genome editing is being used in numerous organisms including microalgae. Microalgae have been subjected to extensive genetic and biological engineering due to their great potential as sustainable biofuel and chemical feedstocks. However, progress in microalgal engineering is slow mainly due to a lack of a proper transformation toolbox, and the same problem also applies to genome editing techniques. Given these problems, there are a few reports on successful genome editing in microalgae. It is, thus, time to consider the problems and solutions of genome editing in microalgae as well as further applications of this exciting technology for other scientific and engineering purposes.

  11. Visual Simulation of Microalgae Growth in Bioregenerative Life Support System

    Science.gov (United States)

    Zhao, Ming

    Bioregenerative life support system is one of the key technologies for future human deep space exploration and long-term space missions. BLSS use biological system as its core unit in combination with other physical and chemical equipments, under the proper control and manipulation by crew to complete a specific task to support life. Food production, waste treatment, oxygen and water regeneration are all conducted by higher plants or microalgae in BLSS, which is the most import characteristic different from other kinds of life support systems. Microalgae is light autotrophic micro-organisms, light undoubtedly is the most import factor which limits its growth and reproduction. Increasing or decreasing the light intensity changes the growth rate of microalgae, and then regulates the concentration of oxygen and carbon dioxide in the system. In this paper, based on the mathematical model of microalgae which grew under the different light intensity, three-dimensional visualization model was built and realized through using 3ds max, Virtools and some other three dimensional software, in order to display its change and impacting on oxygen and carbon dioxide intuitively. We changed its model structure and parameters, such as establishing closed-loop control system, light intensity, temperature and Nutrient fluid’s velocity and so on, carried out computer virtual simulation, and observed dynamic change of system with the aim of providing visualization support for system research.

  12. 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.

  13. 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.

  14. Cultivation of freshwater microalgae in biodiesel wash water.

    Science.gov (United States)

    Sassi, Patrícia Giulianna Petraglia; Calixto, Clediana Dantas; da Silva Santana, Jordana Kaline; Sassi, Roberto; Costa Sassi, Cristiane Francisca; Abrahão, Raphael

    2017-06-21

    Biodiesel wash water is a contaminating industrial effluent that must be treated prior to disposal. The use of this effluent as a low-cost alternative cultivation medium for microalgae could represent a viable supplementary treatment. We cultivated 11 microalgae species with potential use for biodiesel production to assess their growth capacities in biodiesel industrial washing waters. Only Monoraphidium contortum, Ankistrodesmus sp., Chlorococcum sp., and one unidentified Chlorophyceae species grew effectively in that effluent. M. contortum showed the highest growth capacity and had the second highest fatty acid content (267.9 mg g(-1) of DW), predominantly producing palmitic (20.9%), 7,10,13-hexadecatrienoic (14%), oleic (16.2%), linoleic (10.5%), and linolenic acids (23.2%). In the second phase of the experiment, the microalgae were cultivated in biodiesel wash water at 75% of its initial concentration as well as in WC (control) medium. After 21 days of cultivation, 25.8 and 7.2% of the effluent nitrate and phosphate were removed, respectively, and the chemical oxygen demand was diminished by 31.2%. These results suggest the possibility of cultivating biodiesel producing microalgae in industrial wash water effluents.

  15. Technical Note: Development of a Photobioreactor for Microalgae ...

    African Journals Online (AJOL)

    In view of the technical and biological limitations of open pond systems, a study was conducted to develop a cost-effective experimental photobioreactor that would permit efficient cultivation of microalgae for biodiesel production. The photobioreactor was developed using low cost materi- als, cylindrical translucent tubes ...

  16. 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

  17. 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

  18. Isolation of microalgae species from arid environments and ...

    African Journals Online (AJOL)

    Oleic acid (C18: 1) was predominant, ranging between 73.3 and 85.6%. Biodiesel properties were within the ASTM standards. The present study suggested that the four isolates are good for biodiesel production. Keywords: Biodiesel, Chlorella, Chlorococcum, Botyrococcus sp., lipid accumulation, microalgae, Oocystis.

  19. 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.

  20. Management of autotrophic mass cultures of micro-algae

    CSIR Research Space (South Africa)

    Toerien, DF

    1987-01-01

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

  1. Adhesion of Chlamydomonas microalgae to surfaces is switchable by light

    Science.gov (United States)

    Kreis, Christian Titus; Le Blay, Marine; Linne, Christine; Makowski, Marcin Michal; Bäumchen, Oliver

    2018-01-01

    Microalgae are photoactive microbes that live in liquid-infused environments, such as soil, temporary pools and rocks, where they encounter and colonize a plethora of surfaces. Their photoactivity manifests itself in a variety of processes, including light-directed motility (phototaxis), the growth of microalgal populations, and their photosynthetic machinery. Although microbial responses to light have been widely recognized, any influence of light on cell-surface interactions remains elusive. Here, we reveal that the unspecific adhesion of microalgae to surfaces can be reversibly switched on and off by light. Using a micropipette force spectroscopy technique, we measured in vivo single-cell adhesion forces and show that the microalga's flagella provide light-switchable adhesive contacts with the surface. This light-induced adhesion to surfaces is an active and completely reversible process that occurs on a timescale of seconds. Our results suggest that light-switchable adhesiveness is a natural functionality of microalgae to regulate the transition between the planktonic and the surface-associated state, which yields an adhesive adaptation to optimize the photosynthetic efficiency in conjunction with phototaxis.

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

    Science.gov (United States)

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

    2015-05-01

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

  3. 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.

  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

  5. Removal of endocrine disrupting compounds from wastewater by microalgae co-immobilized in alginate beads.

    Science.gov (United States)

    Solé, Alba; Matamoros, Víctor

    2016-12-01

    Microalgae systems have been found to be efficient for removing microcontaminants from wastewater effluents, but the effectiveness of immobilized microalgae for removing endocrine disrupting compounds (EDCs) has not yet been addressed. This paper assesses the effect of free and immobilized microalgae on removal efficiency for 6 EDCs by mixing them in 2.5 L reactors with treated wastewater. The experimental design also included control reactors without microalgae. After 10 days of incubation, 64 and 89% of the NH4-N and 90 and 96% of total phosphorous (TP) had been eliminated in the free microalgae and immobilized microalgae reactors, respectively, while the control reactors eliminated only 40% and 70% of the NH4-N and TP, respectively. Both the free and immobilized microalgae reactors were able to remove up to 80% of most of the studied EDCs within 10 days of incubation. Free microalgae were found to increase the kinetic removal rate for bisphenol A, 17-α-ethinylestradiol, and 4-octylphenol (25%, 159%, and 41%, respectively). Immobilizing the microalgae in alginate beads additionally enhanced the kinetic removal rate for bisphenol AF, bisphenol F, and 2,4-dichlorophenol. This study shows that the use of co-immobilized microalgae-based wastewater treatment systems increases the removal efficiency for nutrients and some EDCs from wastewater effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Toxicity of silver and gold nanoparticles on marine microalgae.

    Science.gov (United States)

    Moreno-Garrido, Ignacio; Pérez, Sara; Blasco, Julián

    2015-10-01

    The increased use of nanomaterials in several novel industrial applications during the last decade has led to a rise in concerns about the potential toxic effects of released engineered nanoparticles (NPs) into the environment, as their potential toxicity to aquatic organisms is just beginning to be recognised. Toxicity of metallic nanoparticles to aquatic organisms, including microalgae, seems to be related to their physical and chemical properties, as well as their behaviour in the aquatic media where processes of dissolution, aggregation and agglomeration can occur. Although the production of these particles has increased considerably in recent years, data on their toxicity on microalgae, especially those belonging to marine or estuarine environments remain scarce and scattered. The literature shows a wide variation of results on toxicity, mainly due to the different methodology used in bioassays involving microalgae. These can range for up to EC50 data, in the case of AgNPs, representing five orders of magnitude. The importance of initial cellular density is also addressed in the text, as well as the need for keeping test conditions as close as possible to environmental conditions, in order to increase their environmental relevance. This review focuses on the fate and toxicity of silver, gold, and gold-silver alloy nanoparticles on microalgae, as key organisms in aquatic ecosystems. It is prompted by their increased production and use, and taking into account that oceans and estuaries are the final sink for those NPs. The design of bioassays and further research in the field of microalgae nanoecotoxicology is discussed, with a brief survey on newly developed technology of green (algae mediated) production of Ag, Au and Ag-Au bimetallic NPs, as well as some final considerations about future research on this field. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. 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)

  8. 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

  9. The Potential of Using Pulsed Electric Field (PEF) Technology as the Cell Disruption Method to Extract Lipid from Microalgae for Biodiesel Production

    OpenAIRE

    JOANNES, COSTANTINE; Sipaut, Coswald Stephen; Dayou, Jedol; Md.Yasir, Suhaimi; Mansa, Rachel Fran

    2016-01-01

    For the past few years, there has been an explosive growth of interest in biodiesel production from algae based crops. Feedstock from microalgae is a highly promising resource and can be used as an alternative for sustainable and renewable energy since; lipid from microalgae can be converted to biodiesel. The study brief reviews of the processes related to microalgae for biodiesel production. This includes the process of microalgae cultivation, microalgae harvesting, extracting microalgae lip...

  10. Effects of short-term sediment nutrient enrichment and grazer (Neritina reclivata removal on sediment microalgae in a shallow eutrophic estuary (Alabama, USA

    Directory of Open Access Journals (Sweden)

    Just Cebrian

    2012-12-01

    sedimentary areas studied. Our findings contrast with the results of past work in sediments with well-lit and nutrient poor conditions, or sediments with high densities of other snail grazers. In conjunction this and other investigations indicate that the response of sediment microalgae to nutrient enrichment and modified grazer abundance depends to a large extent on the initial levels of nutrient availability and grazing before the system is altered.El caracol Neritina reclivata está presente en los sistemas tropicales y subtropicales del Golfo de México, sin embargo, su impacto en los sedimentos de microalgas ha sido poco estudiado. Muchos de los sistemas costeros de todo el mundo están siendo eutrofizados debido a actividades humanas, y al parecer van a seguir siendo eutrofizados en mayor grado en el futuro. La exploración de los efectos individuales y combinados de un mayor enriquecimiento de nutrientes y la herviboría por este caracol en microalgas de sedimentos en estos sistemas eutróficos es una cuestión importante para la comprensión y el manejo de estos sistemas. Aquí se examinan los efectos a corto plazo del enriquecimiento de nutrientes y herviboría del caracol de olivo sobre la biomasa y composición de microalgas de sedimentos en un estuario eutrófico superficial (Weeks Bay. Alabama, USA del norte del Golfo de México. Para esto se llevaron a cabo una serie de experimentos factoriales añadiendo o no nutrientes y removiendo o no el caracol, para un total de cuatro tratamientos en cada experimento: ambiente con herviboría sin nutrimentos añadidos, ambiente con herviboría y nutrimentos añadidos, ambiente sin herviboría sin nutrimentos añadidos, y ambiente sin herviboría con nutrimentos añadidos. No se encontró ningún impacto significativo por la adición de nutrimentos en ninguno de los ocho experimentos a corto plazo (i.e. cuatro días. Los impactos debidos al caracol fueron menores, sólo se encontró un decrecimiento en la biomasa por

  11. Toxinas de cianobactérias e microalgas marinhas: um desafio para a ecotoxicologia aquática

    Directory of Open Access Journals (Sweden)

    Manildo Marcião de Oliveira

    2011-02-01

    Full Text Available O objetivo desta revisão é de chamar a atenção para o crescente número de metabólitos secundários produzidos por microrganismos em ambientes aquáticos. Em especial pelas cianobactérias e pelas microalgas marinhas. O primeiro grupo é produtor de toxinas que têm por alvo o fígado, os nervos e a pele. As cianobactérias são as maiores responsáveis por eventos de intoxicação em ambientes aquáticos epicontinentais. Em ambientes marinhos, microalgas eucariotas como as diatomáceas e principalmente os dinoflagelados são produtores de ampla variedade de ficotoxinas. Ficotoxinas são causadoras de síndromes após consumo de mexilhão contaminado ou intoxicação ciguatérica por consumo de peixe (CFP. O quadro atual sinaliza atenção, pois muitas florações ocorrem sem notificação, o que impede importantes estudos sobre a história de florações sazonais. Aspectos metodológicos e de mão de obra qualificada também dificultam diagnósticos mais precisos sobre as florações. A cooperação entre profissionais com distintas formações como taxonomistas, químicos, biólogos e engenheiros ambientais é a base para estudos ecotoxicológicos que possam avaliar o risco destas florações e sugerir adaptações na legislação ambiental.

  12. Current developments in high-throughput analysis for microalgae cellular contents.

    Science.gov (United States)

    Lee, Tsung-Hua; Chang, Jo-Shu; Wang, Hsiang-Yu

    2013-11-01

    Microalgae have emerged as one of the most promising feedstocks for biofuels and bio-based chemical production. However, due to the lack of effective tools enabling rapid and high-throughput analysis of the content of microalgae biomass, the efficiency of screening and identification of microalgae with desired functional components from the natural environment is usually quite low. Moreover, the real-time monitoring of the production of target components from microalgae is also difficult. Recently, research efforts focusing on overcoming this limitation have started. In this review, the recent development of high-throughput methods for analyzing microalgae cellular contents is summarized. The future prospects and impacts of these detection methods in microalgae-related processing and industries are also addressed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 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.

  14. Application of agar liquid-gel transition in cultivation and harvesting of microalgae for biodiesel production.

    Science.gov (United States)

    Kumar, Vinod; Nanda, Manisha; Verma, Monu

    2017-11-01

    In order to increase microalgal biomass productivity efficient cultivation and harvesting methods are needed against the available traditional methods. The present study focuses on the same by harvesting microalgae using agar gel. Agar medium containing bold's basal medium (BBM) undergoes a thermoreversible gel transition. As compared to the traditional protocols, this gel is used to cultivate microalgae without even affecting the total productivity. To develop the gel for microalgae cultivation, agar was boiled in BBM. Then the agar was cooled to 35°C and microalgae culture was added to it. After seeding the microalgae the temperature of the agar was further decreased by 10°C to induce gelation. Instead of isolated cells microalgae were grown in clusters within the agar gel. Microalgal clusters gravimetrically settle at the bottom within 2h. In this method agar can be reused. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    OpenAIRE

    Guanyi Chen; Liu Zhao; Yun Qi; Yuan-Lu Cui

    2014-01-01

    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 revie...

  17. Progress in microalgae cultivation photobioreactors and applications in wastewater treatment: A review

    OpenAIRE

    Lu Haifeng; Ma Shanshan; Yuanhui Zhang; Liu Zhidan; Duan Na

    2017-01-01

    Using microalgae to treat wastewater has received growing attention in the world because it is regarded as a novel means for wastewater treatment. It is commonly recognized that large-scale cultivation and commercial application of microalgae are limited by the development of photobioreactor (PBR). Although there are a lot of PBRs for microalgae pure cultivation which used culture medium, specialized PBRs designed for wastewater treatment are rare. The composition of wastewater is quite co...

  18. Lipid Producing Microalgae From Several Ecosystems in West and Central Java, Indonesia

    OpenAIRE

    SANTOSA, DWI ANDREAS; SULASTRI

    2010-01-01

    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. Ther...

  19. 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.

  20. Isolation and Fatty Acid Profile of Selected Microalgae Strains from the Red Sea for Biofuel Production

    OpenAIRE

    Hugo Pereira; Luísa Barreira; Luísa Custódio; Salman Alrokayan; Fouzi Mouffouk; João Varela; Khalid M. Abu-Salah; Radhouan Ben-Hamadou

    2013-01-01

    The isolation of lipid-rich autochthonous strains of microalgae is a crucial stage for the development of a microalgae-based biofuel production plant, as these microalgae already have the necessary adaptations to withstand competition, predation and the temperatures observed at each production site. This is particularly important in extreme climates such as in Saudi Arabia. Resorting to fluorescence activated cell sorting (FACS) we screened for and isolated several microalgal strains from sam...

  1. Effect of the temperature on the sorption of cadmium in natural clinoptilolite from the State of Chihuahua; Efecto de la temperatura sobre la sorcion de cadmio en clinoptilolita natural del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Arambula V, V

    2004-07-01

    The investigation works related with the removal of cadmium of aqueous solutions, they make emphasis in a great number of materials that were used for this end, as well as in the parameters that influence, such as the temperature and the pH. In this work it was investigated the effect of the temperature on the removal of cadmium, using a zeolitic mineral native of the State of Chihuahua for they were determined it kinetic parameters, those diffusivity coefficients and the retention mechanisms (adsorption or ion exchange) involved. The clinoptilolite samples were characterized by means of scanning electron microscopy in high vacuum (MEB), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part consisted on putting in contact solutions of cadmium with the mineral, varying the temperature, the time of contact or the concentration; the quantification of sodium and cadmium in the liquid phase was carried out by means of atomic absorption spectroscopy (EAA). It was determined the time of equilibrium for the removal process. The temperature and the concentration influence on the process of sorption of cadmium in the zeolitic mineral (kinetics and isotherms). The kinetic model that describes better the sorption process of cadmium in the clinoptilolite was the pseudo-2 order. The apparent coefficient of diffusivity presented a greater value conforms to increment the temperature. The results of the isotherm of adsorption of cadmium presented a better adjustment to the Freundlich model. The quantity of cadmium retained by the mineral it was greater than the quantity of sodium found in the solution after the contact between the solution of cadmium and the zeolitic mineral and in accordance with the obtained separation factors, the natural zeolite shows a greater affinity for the cadmium that for the sodium ({alpha} > 1). (Author)

  2. 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

  3. Nutritional Evaluation of Australian Microalgae as Potential Human Health Supplements: e0118985

    National Research Council Canada - National Science Library

    Megan Kent; Heather M Welladsen; Arnold Mangott; Yan Li

    2015-01-01

    .... The Australian native microalgae exhibited similar, and in several cases superior, organic nutritional properties relative to the assessed commercial products, with biochemical profiles rich in high...

  4. 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.

  5. CO sub 2 sources for microalgae-based liquid fuel production

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, D.; Karpuk, M.

    1990-08-01

    Researchers in the Aquatic Species Program at the Solar Energy Research Institute are developing species of microalgae that have high percentages of lipids, or oils. These lipids can be extracted and converted to diesel fuel substitutes. Because microalgae need carbon dioxide (CO{sub 2}) as a nutrient, optimal microalgae growth occurs in CO{sub 2}-saturated solutions. For this reason, the authors of this study sought to identify possible large-scale sources of CO{sub 2} for microalgae-based liquid fuels production. The authors concluded that several such promising sources exist. 42 refs., 14 figs., 10 tabs.

  6. Impact of Microalgae-Bacteria Interactions on the Production of Algal Biomass and Associated Compounds

    National Research Council Canada - National Science Library

    Fuentes, Juan Luis; Garbayo, Inés; Cuaresma, María; Montero, Zaida; González-Del-Valle, Manuel; Vílchez, Carlos

    2016-01-01

    A greater insight on the control of the interactions between microalgae and other microorganisms, particularly bacteria, should be useful for enhancing the efficiency of microalgal biomass production...

  7. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2017-10-01

    To achieve the functional specialization of a microalgae community through operational tuning of an open photobioreactor used for biogas upgrading under alkaline conditions. An open photobioreactor was inoculated with an indigenous microalgae sample from the Texcoco Soda Lake. A microalgae community was adapted to fix CO2 from synthetic biogas through different culture conditions reaching a maximum of 220 mg CO2  l(-1) per day. Picochlorum sp. and Scenedesmus sp. were identified as the prominent microalgae genera by molecular fingerprinting (partial sequencing of 16S rRNA and 18S rRNA genes) but only the first was detected by microscopy screening. Changes in the microalgae community profile were monitored by a range-weighted richness index, reaching the lowest value when biogas was upgraded. A robust microalgae community in the open photobioreactor was obtained after different culture conditions. The specialization of microalgae community for CO2 fixation under H2 S presence was driven by biogas upgrading conditions. The alkaline conditions enhance the CO2 absorption from biogas and could optimize specialized microalgae communities in the open photobioreactor. Denaturing gradient gel electrophoresis fingerprinting and richness index comparison are useful methods for the evaluation of microalgae community shifts and photosynthetic activity performance, particularly in systems intended for CO2 removal from biogas where the CO2 assimilation potential can be related to the microbial richness. © 2017 The Society for Applied Microbiology.

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

    Science.gov (United States)

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

    2017-11-01

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

  10. Transcriptomic analysis of the oleaginous microalga Neochloris oleoabundans reveals metabolic insights into triacylglyceride accumulation

    National Research Council Canada - National Science Library

    Rismani-Yazdi, Hamid; Haznedaroglu, Berat Z; Hsin, Carol; Peccia, Jordan

    2012-01-01

    .... Here we report the de novo transcriptome assembly and quantitative gene expression analysis of the oleaginous microalga Neochloris oleoabundans, with a focus on the complex interaction of pathways...

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Science.gov (United States)

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

    2015-10-09

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

  13. Anaerobic digestate as substrate for microalgae culture: the role of ammonium concentration on the microalgae productivity.

    Science.gov (United States)

    Uggetti, Enrica; Sialve, Bruno; Latrille, Eric; Steyer, Jean-Philippe

    2014-01-01

    In spite of the increasing interest received by microalgae as potential alternatives for biofuel production, the technology is still not industrially viable. The utilization of digestate as carbon and nutrients source can enhance microalgal growth reducing costs and environmental impacts. This work assesses microalgal growth utilizing the liquid phase of anaerobic digestate effluent as substrate. The effect of inoculum/substrate ratio on microalgal growth was studied in a laboratory batch experiment conduced in 0.5L flasks. Results suggested that digestate may be an effective substrate for microalgal growth promoting biomass production up to 2.6 gTSS/L. Microalgal growth rate was negatively affected by a self-shading phenomenon, while biomass production was positively correlated with the inoculum and substrate concentrations. Thus, the increasing of both digestate and microalgal initial concentration may reduce the initial growth rate (μ from 0.9 to 0.04 d(-1)) but significantly enhances biomass production (from 0.1 to 2.6 gTSS/L). Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Cadmio en sangre y su relación con el consumo de tabaco en una población laboral hospitalaria Blood cadmium and its relationship with smoking in a hospital employee population Cádmio presente no sangue e a sua relação com o consumo de tabaco numa população de trabalhadores de um hospital

    Directory of Open Access Journals (Sweden)

    Cristina Fernández Pérez

    2012-12-01

    Full Text Available La exposición de la población general al cadmio es un problema de salud pública, siendo las principales fuentes tanto el consumo de tabaco como la exposición al humo del mismo.El objetivo de este trabajo fue determinar la concentración de cadmio en sangre en una población laboral hospitalaria y su asociación con el consumo de tabaco.Se administró el cuestionario PESA® a 395 sujetos. El cadmio en sangre se midió por espectrometría de absorción atómica con atomización electrotérmica.La mediana de cadmio en sangre fue 0,29 μg/L. La mediana de cadmio de los fumadores (0,83 μg/L fue la más elevada y la de los exfumadores (0,31 μg/L fue a su vez más elevada que la de aquellos que nunca habían fumado (0,21 μg/L. Dentro del grupo de fumadores, se observó una asociación entre la concentración de cadmio y el número de cigarrillos inhalados.En el grupo de exfumadores se observó una asociación con el número de cigarrillos que habían consumido y una correlación negativa entre el tiempo transcurrido desde el abandono del hábito tabáquico y la concentración de cadmio en sangre.Dentro del grupo de los que nunca habían fumado, se observó una diferencia entre la concentración de cadmio de los fumadores pasivos (0,24 μg/L y los que no lo eran (0,20 μg/L.La concentración de cadmio en sangre se relacionó con el consumo de tabaco. Son necesarios más estudios para confirmar el hallazgo de concentraciones de cadmio más elevadas en los fumadores pasivos.Exposure to cadmium is a public health problem due to the broad exposure to this toxic substance among the general population. The main sources of exposure are both tobacco consumption and tobacco smoke.The aim of this study was to determine the blood cadmium concentration in an employee population drawn from our hospital and its association with tobacco consumption.The exposure questionnaire PESA® was administered to 395 employees. Blood cadmium was measured by electrothermal

  15. Allelopathic activity of the Baltic cyanobacteria against microalgae

    Science.gov (United States)

    Żak, Adam; Musiewicz, Krzysztof; Kosakowska, Alicja

    2012-10-01

    The goal of this work was to investigate the influence of Baltic cyanobacteria Anabaena variabilis and Nodularia spumigena cells and cell-free filtrates on the growth of green algae Chlorella vulgaris. We have demonstrated that Anabaena variabilis and Nodularia spumigena caused allelopathic effects against microalgae. The cyanobacterial and microalgal cultures were provided on liquid medium, in 22 °C at continuous light. Cell-free filtrates were obtained by centrifugation and filtering aliquots of cyanobacterial cultures (including cultures in exponential and stationary phase of growth). Growth response of free cells (batch culture technique) and immobilized cultures (in alginate beads) of the unicellular green algae to cyanobacteria allelochemicals were tested and compared. In this experiment Anabaena variabilis supressed the growth of microalgae compared to control samples. Nodularia spumigena stimulated the growth of Chlorella vulgaris in most cases, however both positive and negative effects were observed.

  16. 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. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. ECONOMIC ANALYSIS OF MICROALGAE BASED BIOGAS COGENERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Ebru Akkaya

    2016-12-01

    Full Text Available In this study, economic analysis of the cogeneration system using the biogas produced in the anaerobic reactor feed by microalgae has been performed. This system consists of the following main parts; pool open channel for growing microalgae, pre-concentration section, high-rate anaerobic reactor for producing biogas and cogeneration section that biogas is converted into electricity and heat energy. An economic model to investigate the viability of such a system has been given. The present worth of the net profit, the annual equivalent, rate of return, pay-back time are considered as an economic evaluation criteria. In addition, a sensitivity analysis has been performed in order to show the effects of technical and economic parameters on the system economy.

  18. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. In situ transesterification of highly wet microalgae using hydrochloric acid.

    Science.gov (United States)

    Kim, Bora; Im, Hanjin; Lee, Jae W

    2015-06-01

    This study addresses in situ transesterification of highly wet microalgae with hydrochloric acid (HCl) as a catalyst. In situ transesterification was performed by heating the mixture of wet algal cells, HCl, methanol, and solvent in one pot, resulting in the fatty acid methyl ester (FAME) yield over 90% at 95°C. The effects of reaction variables of temperature, amounts of catalyst, reactant, and solvent, and type of solvents on the yield were investigated. Compared with the catalytic effect of H2SO4, in situ transesterification using HCl has benefits of being less affected by moisture levels that are as high as or above 80%, and requiring less amounts of catalyst and solvent. For an equimolar amount of catalyst, HCl showed 15wt.% higher FAME yield than H2SO4. This in situ transesterification using HCl as a catalyst would help to realize a feasible way to produce biodiesel from wet microalgae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Phytohormones in microalgae: a new opportunity for microalgal biotechnology?

    Science.gov (United States)

    Lu, Yandu; Xu, Jian

    2015-05-01

    Phytohormones, including auxin, abscisic acid (ABA), cytokinin (CK), ethylene (ET), and gibberellins (GAs), have been found in a broad spectrum of microalgal lineages. Although the functional role of microalgal endogenous phytohormones remains elusive, molecular evidence from the oleaginous microalga Nannochloropsis oceanica suggests that endogenous ABA and CK are functional and that their physiological effects are similar to those in higher plants. In this Opinion article, proceeding from genome-based metabolic reconstruction, we suggest that modern higher plant phytohormone biosynthesis pathways originate from ancient microalgae even though some of the microalgal phytohormone signaling pathways remain unknown. Dissection and manipulation of microalgal phytohormone systems could offer a new view of phytohormone evolution in plants and present new opportunities in developing microalgal feedstock for biofuels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. 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.

  2. Nutritional Evaluation of Australian Microalgae as Potential Human Health Supplements

    Science.gov (United States)

    Kent, Megan; Welladsen, Heather M.; Mangott, Arnold; Li, Yan

    2015-01-01

    This study investigated the biochemical suitability of Australian native microalgal species Scenedesmus sp., Nannochloropsis sp., Dunaliella sp., and a chlorophytic polyculture as nutritional supplements for human health. The four microalgal cultures were harvested during exponential growth, lyophilized, and analysed for proximate composition (moisture, ash, lipid, carbohydrates, and protein), pigments, and amino acid and fatty acid profiles. The resulting nutritional value, based on biochemical composition, was compared to commercial Spirulina and Chlorella products. The Australian native microalgae exhibited similar, and in several cases superior, organic nutritional properties relative to the assessed commercial products, with biochemical profiles rich in high-quality protein, nutritious polyunsaturated fats (such as α-linolenic acid, arachidonic acid, and eicosapentaenoic acid), and antioxidant pigments. These findings indicate that the microalgae assessed have great potential as multi-nutrient human health supplements. PMID:25723496

  3. Beneficial effect of peptides from microalgae on anticancer.

    Science.gov (United States)

    Kang, Kyong-Hwa; Kim, Se-Kwon

    2013-05-01

    Biologically active compounds with different modes of action, such as, antiproliferative, antioxidant, antimicrotubule, have been isolated from marine sources, specifically microalgae, cyanobacteria and seaweed. The structural characteristics of these peptides include various unusual amino acid residues, which may be responsible for their properties. Moreover, protein hydrolysates formed by the enzymatic digestion of aquatic and marine by-products are an important source of bioactive peptides. Purified peptides from these sources have been shown to have antioxidant activity and cytotoxic effect on several human cancer cell lines such as HepG2, HeLa, AGS, and MCF-7. These characteristics imply that the use of peptides from marine sources has potential for the prevention and treatment of cancer, and that they might also be useful as molecular models in anticancer drug research.This review focuses about the anticancer activating of peptides were prepared from microalgae in detail.

  4. Nutritional evaluation of Australian microalgae as potential human health supplements.

    Directory of Open Access Journals (Sweden)

    Megan Kent

    Full Text Available This study investigated the biochemical suitability of Australian native microalgal species Scenedesmus sp., Nannochloropsis sp., Dunaliella sp., and a chlorophytic polyculture as nutritional supplements for human health. The four microalgal cultures were harvested during exponential growth, lyophilized, and analysed for proximate composition (moisture, ash, lipid, carbohydrates, and protein, pigments, and amino acid and fatty acid profiles. The resulting nutritional value, based on biochemical composition, was compared to commercial Spirulina and Chlorella products. The Australian native microalgae exhibited similar, and in several cases superior, organic nutritional properties relative to the assessed commercial products, with biochemical profiles rich in high-quality protein, nutritious polyunsaturated fats (such as α-linolenic acid, arachidonic acid, and eicosapentaenoic acid, and antioxidant pigments. These findings indicate that the microalgae assessed have great potential as multi-nutrient human health supplements.

  5. Hypolipidemic, Antioxidant and Antiinflammatory Activities of Microalgae Spirulina

    OpenAIRE

    Deng, Ruitang; Chow, Te-Jin

    2010-01-01

    Spirulina is free-floating filamentous microalgae growing in alkaline water bodies. With its high nutritional value, Spirulina has been consumed as food for centuries in Central Africa. It is now widely used as nutraceutical food supplement worldwide. Recently, great attention and extensive studies have been devoted to evaluate its therapeutic benefits on an array of diseased conditions including hypercholesterolemia, hyperglycerolemia, cardiovascular diseases, inflammatory diseases, cancer a...

  6. Applications of Diatoms as Potential Microalgae in Nanobiotechnology

    OpenAIRE

    Jamali, Ali Akbar; Akbari, Fariba; Ghorakhlu, Mohamad Moradi; de la Guardia, Miguel; Yari Khosroushahi, Ahmad

    2012-01-01

    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 ...

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

    OpenAIRE

    Blinová Lenka; Bartošová Alica; Gerulová Kristína

    2015-01-01

    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 b...

  8. "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

  9. 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.

  10. A Novel Enclosed Online Control System for Microalgae Production

    Directory of Open Access Journals (Sweden)

    Bin Li

    2014-03-01

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

  11. Relationship between microalgae extracts composition and rheological properties

    OpenAIRE

    AUDO, Mariane; QUEFFELEC, Clémence; LEPINE, Olivier; LEGRAND, Jack; CHAILLEUX, Emmanuel; BUJOLI, Bruno

    2011-01-01

    All over the world, the last decade has seen an increasing scientific interest in microalgae. Their high growth rate, their high photosynthetic yield, and their high oil content make it an interesting renewable ressource to produce bioenergies. Moreover, they don't compete with human feeding. To reach an economic viability, all fractions of this new industry must be valorised (proteins, lipids, polysaccharides), so that the algo-refinery concept is achieved. We herein propose to valorise the ...

  12. Developing Molecular Tools To Genetically Engineer The Microalga Nannochloropsis

    OpenAIRE

    Anley, Kominist Asmamaw

    2015-01-01

    The main objective of this thesis was to develop an efficient transformation protocol for Nannochloropsis oceanica CCMP1779 by biolistic transformation using the linearized pSELECT100 plasmid which confers hygromycin B resistance. In addition the toxicity of several antibiotics for different Nannochloropsis species was determined. Nannochloropsis is the genus of unicellular photosynthetic microalgae in the class of Eustigmatophyceae, which have industrial significance due to their producti...

  13. Antifouling microfiltration strategies to harvest microalgae for biofuel.

    Science.gov (United States)

    Ríos, Sergio D; Salvadó, Joan; Farriol, Xavier; Torras, Carles

    2012-09-01

    Microalgae are microorganisms that can fix CO(2) by using the energy from the sun and transforming it into organic molecules such as lipids (i.e. feedstock for biodiesel production). Microfiltration is a promising method to be considered in the harvesting step. In this study, two antifouling methods were tested in order to minimize permeability decrease over time, at low trans-membrane pressure filtration. Preliminary experiments were performed to find optimum conditions of transmembrane pressure, rotational speed and membrane pore size. Pilot experiments were carried out in the optimal conditions using microalgae obtained from the culture step and from a previous concentration process based on sedimentation. Fouling was significantly minimized, and the permeability plateau increased up to 600 L/h/m(2)/bar. Three microalgae species were tested: Phaeodactylum tricornutum (Pht), Nannochloropsis gaditana (Nng) and Chaetoceros calcitrans (Chc). An economic assessment was also performed, which demonstrated that dynamic filtration is economically more efficient than tangential cross-flow filtration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Microalgae dewatering based on forward osmosis employing proton exchange membrane.

    Science.gov (United States)

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

    2017-11-01

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

  15. 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.

  16. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Spectral optical properties of selected photosynthetic microalgae producing biofuels

    Science.gov (United States)

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

    2013-01-01

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

  18. Polishing of municipal secondary effluent using native microalgae consortia.

    Science.gov (United States)

    Beltrán-Rocha, Julio César; Barceló-Quintal, Icela Dagmar; García-Martínez, Magdalena; Osornio-Berthet, Luis; Saavedra-Villarreal, Nidia; Villarreal-Chiu, Juan; López-Chuken, Ulrico Javier

    2017-04-01

    This work evaluates the use of native microalgae consortia for a dual role: polishing treatment of municipal wastewater effluents and microalgae biomass feedstock potential for biodiesel or biofertilizer production. An initial screening was undertaken to test N and P removal from secondary effluents and biomass production by 12 consortia. A subsequent treatment was performed by selected consortia (01 and 12) under three operational conditions: stirring (S), S + 12 h of daily aeration (S + A) and S + A enriched with CO 2 (S + AC). All treatments resulted in compliance with environmental regulations (e.g. Directive 91/271/EEC) and high removal efficiency of nutrients: 64-79% and 80-94% of total N and PO 4 3- -P respectively. During the experiments it was shown that pH alkalinization due to microalgae growth benefits the chemical removal of ammonia and phosphorus. Moreover, advantages of pH increase could be accomplished by intermittent CO 2 addition which in this research (treatment S + AC) promoted higher yield and lipid concentration. The resulting dry biomass analysis showed a low lipid content (0.5-4.3%) not ideal for biodiesel production. Moreover, the high rate of ash (29.3-53.0%) suggests that biomass could be readily recycled as a biofertilizer due to mineral supply and organic constituents formed by C, N and P (e.g. carbohydrate, protein, and lipids).

  19. Cultivation of microalgae in dairy farm wastewater without sterilization.

    Science.gov (United States)

    Ding, Jinfeng; Zhao, Fengmin; Cao, Youfu; Xing, Li; Liu, Wei; Mei, Shuai; Li, Shujun

    2015-01-01

    The present study investigated the feasibility of cultivating microalgae in dairy farm wastewater. The growth of microalgae and the removal rate of the nutrient from the wastewater were examined. The wastewater was diluted 20, 10 and 5 times before applied to cultivate microalgae. A 5 dilution yielded 0.86 g/L dry weight in 6 days with a relative growth rate of 0.28 d(-1), the 10×dilution gave 0.74 g/L and a relative growth rate of 0.26 d(-1) while the 20×dilution 0.59 g/L and a relative growth rate 0.23 d(-1). The nutrients in the wastewater could be removed effectively in different diluted dairy wastewater. The greatest dilution (20×) showed the removal rates: ammonia, 99.26%; P, 89.92%; COD, 84.18%. A 10×dilution removal% was: ammonia 93; P 91 and COD 88. The 5× dilution removal% was: ammonia 83; P 92; COD 90.

  20. 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. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  1. Wastewater treatment to enhance the economic viability of microalgae culture.

    Science.gov (United States)

    Pires, J C M; Alvim-Ferraz, M C M; Martins, F G; Simões, M

    2013-08-01

    Microalgae culture is still not economically viable and it presents some negative environmental impacts, concerning water, nutrient and energy requirements. In this context, this study aims to review the recent advances on microalgal cultures in wastewaters to enhance their economic viability. We focused on three different culture concepts: (1) suspended cell systems, (2) cell immobilization, and (3) microalgae consortia. Cultures with suspended cells are the most studied. The nutrient removal efficiencies are usually high for wastewaters of different sources. However, biomass harvesting is difficult and a costly process due to the small cell size and lower culture density. On the other hand, the cell immobilization systems showed to be the solution for this problem, having as main limitation the nutrient diffusion from bulk to cells, which results in a reduced nutrient removal efficiency. The consortium between microalgae and bacteria enhances the growth of both microorganisms. This culture concept showed to be a promising technology to improve wastewater treatment, regarding not only nutrient removal but also biomass harvesting by bioflocculation. The aggregation mechanism must be studied in depth to find the process parameters that would lead to an effective and cheap harvesting process.

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

    Science.gov (United States)

    Han, Wei; Clarke, William; Pratt, Steven

    2015-10-01

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

  3. Flow cytometry for the development of biotechnological processes with microalgae.

    Science.gov (United States)

    Hyka, P; Lickova, S; Přibyl, P; Melzoch, K; Kovar, K

    2013-01-01

    The current interest in microalgae as a sustainable source of next generation biofuels and other valuable substances is driving exploration of their use as unique biotechnological production systems. To design and optimise appropriate production strategies, the behaviour of particular microalgal species should be well characterised under different culture conditions. Thus, flow cytometric (FCM) methods, which are already well established in environmental and toxicological studies of microalgae, are also useful for analysing the physiological state of microalgae, and have the potential to contribute to the rapid development of feasible bioprocesses. These methods are commonly based on the examination of intrinsic features of individual cells within a population (such as autofluorescence or size). Cells possessing the desired physiological or morphological features, which are detectable with or without fluorescent staining, are counted or isolated (sorted) using an FCM device. The options for implementation of FCM in the development of biotechnological processes detailed in this review are (i) analysing the chemical composition of biomass, (ii) monitoring cellular enzyme activity and cell viability, and (iii) sorting cells to isolate those overproducing the target compound or for the preparation of axenic cultures. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. 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

  5. Toxicological effects of phenol on four marine microalgae.

    Science.gov (United States)

    Duan, Weiyan; Meng, Fanping; Lin, Yufei; Wang, Guoshan

    2017-06-01

    The toxic effects of phenol on four marine microalgae (Dunaliella salina, Platymonas subcordiformis, Phaeodactylum tricornutum Bohlin, and Skeletonema costatum) were evaluated. The 96h EC 50 values were 72.29, 92.97, 27.32, and 27.32mgL -1 , respectively, which were lower than those values of freshwater microalgae reported in the literature. During a 96-h exposure to a sub-lethal concentration of phenol (1/2 96h EC 50 ) with green alga (D. salina) and diatom (S. costatum), reactive oxygen species (ROS) accumulation, and chlorophyll a (Chl a) content decrease were simultaneously observed in diatom cells after 48h treatment. On the contrary, other chlorophylls in both algae were unaffected. Under transmission electron microscopy (TEM), the phenol-induced ultrastructure alterations included disappearance, or shrinkage, of nucleolus and enlargement of vacuoles, which may result in programmed cell death (PCD). The increase in number of lipid droplets may be related to phenol detoxification. These results indicate that the sensitivity of marine microalgae to phenol was dependent on some biotic factors such as cell size, ROS production, and phenol degradation ability in algal cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. 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.

  7. An overview of the utilisation of microalgae biomass derived from nutrient recycling of wet market wastewater and slaughterhouse wastewater

    OpenAIRE

    A. Y. Maizatul; Radin Maya Saphira Radin Mohamed; Adel A. Al-Gheethi; M. K. Amir Hashim

    2017-01-01

    Abstract Microalgae have high nutritional values for aquatic organisms compared to fish meal, because microalgae cells are rich in proteins, lipids, and carbohydrates. However, the high cost for the commercial production of microalgae biomass using fresh water or artificial media limits its use as fish feed. Few studies have investigated the potential of wet market wastewater and slaughterhouse wastewater for the production of microalgae biomass. Hence, this study aims to highlight the potent...

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

    OpenAIRE

    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 nee...

  9. Bioprospecting North Atlantic microalgae with fast growth and high polyunsaturated fatty acid (PUFA) content for microalgae-based technologies.

    Science.gov (United States)

    Steinrücken, Pia; Erga, Svein Rune; Mjøs, Svein Are; Kleivdal, Hans; Prestegard, Siv Kristin

    2017-09-01

    Microalgae are considered to be an important and sustainable alternative to fish oil as a source for the polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Due to their health benefits, there is an increasing interest in the commercial application of these fatty acids (FA) to health and dietary products, and to aquaculture feeds. However, FA from microalgae are still expensive to produce compared to fish or plant oils. With only a few microalgal strains being cultivated on a large scale for commercial PUFA production, prospecting for new, robust and fast-growing strains with increased PUFA content is essential in order to reduce production costs. Microalgae from northern high latitudes, exposed to cold temperatures, may be especially promising candidates as previous studies have shown increasing unsaturation of FA in response to decreasing growth temperatures in different microalgae, most likely to maintain membrane fluidity and function. We have designed a screening pipeline, targeting a focused search and selection for marine microalgal strains from extreme North Atlantic locations with high robustness and biomass production, and increased levels of EPA and DHA. The pipeline includes a rational sampling plan, isolation and cultivation of clonal strains, followed by a batch growth experiment designed to obtain information on robustness, growth characteristics, and the FA content of selected isolates during both nutrient replete exponential cultivation and nutrient limited stationary cultivation. A number of clonal cultures (N = 149) have been established, and twenty of these strains have been screened for growth and FA content and composition. Among those strains, three showed growth rates ≥ 0.7 d- 1 at temperatures of 15 °C or below, and high amounts of EPA (> 3% DW), suggesting their potential as candidates for large scale production.

  10. Inventory of Sources of Available Saline Waters for Microalgae Mass Culture in the State of Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, L. G.; Olson, K. L.; Wallace, M. G.; Osborn, M. D.

    1986-06-25

    The Solar Energy Research Institute (SERI) is conducting research on the development of microalgae biomass systems for the production of liquid fuels. Particularly appealing at this time, is the idea of using indigenous resources of the Southwest for large-scale production of microalgae.

  11. 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

  12. [Recent progress in treatment of aquaculture wastewater based on microalgae--a review].

    Science.gov (United States)

    Meng, Fanping; Gong, Yanyan; Ma, Dongdong

    2009-06-01

    Microalgae enables aquaculture wastewater recycling through a biological conversion. Recently, many studies have been reported on microalgae cultivation and wastewater treatment, including developing various wastewater treatment technologies such as algae pond, activated algae, immobilized algae and algae photo-bioreactor. In this review, we address the mechanisms, progress and application in the purification of aquaculture wastewater, as well as some research perspectives.

  13. 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

  14. 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

  15. The impact of nitrogen starvation on the dynamics of triacylglycerol accumulation in nine microalgae strains

    NARCIS (Netherlands)

    Breuer, G.; Lamers, P.P.; Martens, D.E.; Draaisma, R.B.; Wijffels, R.H.

    2012-01-01

    Microalgae-derived lipids are an alternative to vegetable and fossil oils, but lipid content and quality vary among microalgae strains. Selection of a suitable strain for lipid production is therefore of paramount importance. Based on published results for 96 species, nine strains were selected to

  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

  17. 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

  18. 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

  19. Interactions of microalgae and other microorganisms for enhanced production of high-value compounds.

    Science.gov (United States)

    Lutzu, Giovanni Antonio; Turgut Dunford, Nurhan

    2018-03-01

    The cultivation of microalgae for the production of biomass and associated valuable compounds has gained increasing interest not only within the scientific community but also at the industrial level. Microalgae cells are capable of producing high-value compounds that are widely used in food, feed, pharmaceutical, medical, nutraceutical, cosmeceutical, and aquaculture industries. For example, lipids produced by algae can be converted to biodiesel, other fuels and bio-products. Hence, high oil content algal biomass has been regarded as a potential alternative feedstock to replace terrestrial crops for sustainable production of bio-products. It has been reported that the interaction of microalgae and other microorganisms greatly enhances the efficiency of microalgal biomass production and its chemical composition. Microalgae-bacteria interaction with an emphasis on the nature of symbiotic relationship in mutualisitc and parasitic consortia has been extensively studied. For instance, it is well documented that production of vitamins or growth promoting factors by bacteria enhances the growth of microalgae. Little attention has been paid to the consortia formed by microalgae and other microorganisms such as other microalgae strains, cyanobacteria, fungi, and yeasts. Hence, the aim of this review is to investigate the impact of the microalgae-other microorganism interactions on the production of high value compounds.

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

    Science.gov (United States)

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

    2016-03-01

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  2. 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.

  3. 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.

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

    Science.gov (United States)

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

    2014-12-01

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

  5. 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.

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

    Science.gov (United States)

    Costa, Jorge Alberto Vieira; de Morais, Michele Greque

    2011-01-01

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

  7. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Luo, Xuan; Su, Peng; Zhang, Wei

    2015-01-01

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

  9. Effect of microalgae incorporation on physicochemical and textural properties in wheat bread formulation.

    Science.gov (United States)

    García-Segovia, Purificación; Pagán-Moreno, María J; Lara, Irene F; Martínez-Monzó, Javier

    2017-07-01

    The objective of this study was to evaluate the effect of the incorporation of different microalgae on physicochemical and textural properties of bread. Four species of microalgae Isochrysis galbana, Tetraselmis suecica, Scenedesmus almeriensis, and Nannochloropsis gaditana were used in this study. Properties such as water activity, pH, microbiological counts, viscosity, and color were analyzed to determine the effect of microalgae addition on sourdough. The technological quality of breads was analyzed in terms of physicochemical properties, color, texture profile, and porosity. The main effect of microalgae addition was changes in bread color, crust, and crumb that implies an increase of browning and an evolution to more green-yellow tonalities. The textural parameters of breads such as hardness, chewiness, and resilience are not modified by microalgae addition.

  10. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. DNA Barcoding Green Microalgae Isolated from Neotropical Inland Waters

    Science.gov (United States)

    Hadi, Sámed I. I. A.; Santana, Hugo; Brunale, Patrícia P. M.; Gomes, Taísa G.; Oliveira, Márcia D.; Matthiensen, Alexandre; Oliveira, Marcos E. C.; Silva, Flávia C. P.; Brasil, Bruno S. A. F.

    2016-01-01

    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. PMID:26900844

  12. National microalgae biofuel production potential and resource demand

    Science.gov (United States)

    Wigmosta, Mark S.; Coleman, André M.; Skaggs, Richard J.; Huesemann, Michael H.; Lane, Leonard J.

    2011-03-01

    Microalgae are receiving increased global attention as a potential sustainable "energy crop" for biofuel production. An important step to realizing the potential of algae is quantifying the demands commercial-scale algal biofuel production will place on water and land resources. We present a high-resolution spatiotemporal assessment that brings to bear fundamental questions of where production can occur, how many land and water resources are required, and how much energy is produced. Our study suggests that under current technology, microalgae have the potential to generate 220 × 109 L yr-1 of oil, equivalent to 48% of current U.S. petroleum imports for transportation. However, this level of production requires 5.5% of the land area in the conterminous United States and nearly three times the water currently used for irrigated agriculture, averaging 1421 L water per liter of oil. Optimizing the locations for microalgae production on the basis of water use efficiency can greatly reduce total water demand. For example, focusing on locations along the Gulf Coast, southeastern seaboard, and Great Lakes shows a 75% reduction in consumptive freshwater use to 350 L per liter of oil produced with a 67% reduction in land use. These optimized locations have the potential to generate an oil volume equivalent to 17% of imports for transportation fuels, equal to the Energy Independence and Security Act year 2022 "advanced biofuels" production target and utilizing some 25% of the current irrigation demand. With proper planning, adequate land and water are available to meet a significant portion of the U.S. renewable fuel goals.

  13. 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.

  14. Impact of inorganic contaminants on microalgae productivity and bioremediation potential.

    Science.gov (United States)

    Torres, Eric M; Hess, Derek; McNeil, Brian T; Guy, Tessa; Quinn, Jason C

    2017-05-01

    As underdeveloped nations continue to industrialize and world population continues to increase, the need for energy, natural resources, and goods will lead to ever increasing inorganic contaminants, such as heavy metals, in various waste streams that can have damaging effects on plant life, wildlife, and human health. This work is focused on the evaluation of the potential of Nannochloropsis salina to be integrated with contaminated water sources for the concurrent production of a biofuel feedstock while providing an environmental service through bioremediation. Individual contaminants (As, Cd, Cr, Co, Cu, Pb, Ni, Hg, Se, and Zn) at various concentrations ranging from a low concentration (1X) to higher concentrations (10X, and 40X) found in contaminated systems (mine tailings, wastewater treatment plants, produced water) were introduced into growth media. Biological growth experimentation was performed in triplicate at the various contaminant concentrations and at 3 different light intensities. Results show that baseline concentrations of each contaminant slightly decreased biomass growth to between 89% and 99% of the control with the exception of Ni which dramatically reduced growth. Increased contaminant concentrations resulted in progressively lower growth rates for all contaminants tested. Lipid analysis shows most baseline contaminant concentrations slightly decrease or have minimal effects on lipid content at all light levels. Trace contaminant analysis on the biomass showed Cd, Co, Cu, Pb, and Zn were sorbed by the microalgae with minimal contaminants remaining in the growth media illustrating the effectiveness of microalgae to bioremediate these contaminants when levels are sufficiently low to not detrimentally impact productivity. The microalgae biomass was less efficient at sorption of As, Cr, Ni, and Se. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Lipids and lipolytic enzymes of the microalga Isochrysis galbana

    Directory of Open Access Journals (Sweden)

    Hubert Florence

    2017-07-01

    Full Text Available Marine microalgae are now well-known for their ability to produce omega-3 long chain polyunsaturated fatty acids (PUFAs such as docosahexaenoic acid (DHA and eicosapentaenoic acid (EPA. Among these microalgae, Isochrysis galbana has received increasing interest especially because of its high DHA content and its common use in hatchery to feed fish larvae and clams. Moreover, lipolysis occurring from the biomass harvest stage suggests that I. galbana may contain lipolytic enzymes with potential interesting selectivities. For these reasons, the potential of this microalga for the production of valuable lipids and lipolytic enzymes was investigated. Lipid analysis revealed that DHA is mainly located at the sn-2 position of the phospholipids. Thus, I. galbana was considered as an interesting starting material for the lipase catalyzed production of 1-lyso-2-DHA-phospholipids which are considered as convenient vehicles for the conveyance of DHA to the brain. Lipids from I. galbana can also be used for the enzyme-catalyzed production of structured phospholipids containing one DHA and one medium chain fatty acid in order to combine interesting therapeutic and biological benefits. Starting from total RNA extract from I. galbana, coding sequences of putative lipolytic enzymes were obtained by RACE and Nested PCR. The heterologous expression of a sequence designated IgTeCe was implemented. An expression plasmid was constructed by ligating the coding sequence to a plasmid vector and then cloned and expressed in E. coli. Results showed the effective functionality of plasmid construction for the production of a recombinant protein with the expected molecular mass. Moreover, local alignment using BLASTP and biochemical evidences support the hypothesis that the expressed protein is a thioesterase.

  16. Research of Biogas Purification Using Microalgae Monoraphidium Griffithii Suspension

    Directory of Open Access Journals (Sweden)

    Živilė Bingelytė

    2017-09-01

    Full Text Available Using biogas instead of fossil fuels decreases pollutants such as solid particles, sulphur dioxide, nitrogen oxides concentrations in the environment. Green energy and development of relevant infrastructure improves air quality considerably. Chemical, physical, biological methods are used for biogas purification. The main difficulties using biological methods are selection of suitable microorganisms’ suspensions and making optimal conditions in photobioreactor. Different origin and structure microalgae suspensions are used applying biological treatment methods. Monoraphidium griffithi, which is widespread in fresh water, has relatively high potential. Microalgae’ cultures absorb the main components of biogas – carbon dioxide (CO2 and hydrogen sulphide (H2S. Absorbtion processes are based on photosynthesis. Microalgae absorb specific components of biogas when there are suitable light source and nutrient solvent. The main purposes of the research are to asses emission of biogas using different substrates (chicken manure and wastewater sludge. Also, it was measured main physical and chemical characteristics of both substrates: acidicy, temperature, redox potential, conductivity, biohemical oxygen demand. According results of the research, emission from wastewater sludge is greater than from chicken manure so sludge was chosen in teh next stage of the research. The next stage – asssessment of purification efficienty using Monoraphidium grifftihii suspension. Raw biogas was supplied to photobioreacor (with microalgae suspension. Alterations of methane, carbon dioxide, oxygen, hydrogen sulphide concentrations were measured precisely. According to results concentration of methane in the beginning of the researc was 62%, after 35 days – 69%. Meanwhile carbon dioxide – 37% and 31% by analogy. Experimental research alows to assess Monoraphidium griffithi absorption capacity of ballast components. Results were compared to different scientists

  17. 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.

  18. Identification of characteristic fatty acids to quantify triacylglycerols in microalgae

    Directory of Open Access Journals (Sweden)

    Peili eShen

    2016-02-01

    Full Text Available The fatty acid profiles of lipids from microalgae are unique. Polyunsaturated fatty acids are generally enriched in polar lipids, whereas saturated and monounsaturated fatty acids constitute the majority of fatty acids in triacylglycerols (TAG. Each species has characteristic fatty acids, and their content is positively or negatively correlated with TAGs. The marine oleaginous diatom Phaeodactylum tricornutum was used as the paradigm to determine the quantitative relationship between TAG and characteristic fatty acid content. Fatty acid profiles and TAG content of Phaeodactylum tricornutum were determined in a time course. C16:0/C16:1 and eicosapentaenoic acid (EPA, C20:5n3 were identified as characteristic fatty acids in TAGs and polar lipids, respectively. The percentage of those characteristic fatty acids in total fatty acids had a significant linear relationship with TAG content and thus the correlation coefficient presenting r2 were 0.96, 0.94 and 0.97 respectively. The fatty acid-based method for TAG quantification could also be applied to other microalgae such as Nannochloropsis oceanica in which the r2 of C16:0, EPA were 0.94, 0.97 respectively and Chlorella pyrenoidosa, whose r2 value correspondingly between C18:1, C18:3 and TAG content were 0.91, 0.99 as well. This characteristic fatty acid-based method provided a distinct way to quantify TAGs in microalgae, by which TAGs could be measured precisely by immediate transesterification from wet biomass rather than using conventional methods. This procedure simplified the operation and required smaller samples than conventional methods.

  19. Identification of Characteristic Fatty Acids to Quantify Triacylglycerols in Microalgae.

    Science.gov (United States)

    Shen, Pei-Li; Wang, Hai-Tao; Pan, Yan-Fei; Meng, Ying-Ying; Wu, Pei-Chun; Xue, Song

    2016-01-01

    The fatty acid profiles of lipids from microalgae are unique. Polyunsaturated fatty acids are generally enriched in polar lipids, whereas saturated and monounsaturated fatty acids constitute the majority of fatty acids in triacylglycerols (TAG). Each species has characteristic fatty acids, and their content is positively or negatively correlated with TAGs. The marine oleaginous diatom Phaeodactylum tricornutum was used as the paradigm to determine the quantitative relationship between TAG and characteristic fatty acid content. Fatty acid profiles and TAG content of Phaeodactylum tricornutum were determined in a time course. C16:0/C16:1 and eicosapentaenoic acid (EPA, C20:5n3) were identified as characteristic fatty acids in TAGs and polar lipids, respectively. The percentage of those characteristic fatty acids in total fatty acids had a significant linear relationship with TAG content, and thus, the correlation coefficient presenting r (2) were 0.96, 0.94, and 0.97, respectively. The fatty acid-based method for TAG quantification could also be applied to other microalgae such as Nannochloropsis oceanica in which the r (2) of C16:0 and EPA were 0.94 and 0.97, respectively, and in Chlorella pyrenoidosa r (2)-values for C18:1 and C18:3 with TAG content were 0.91 and 0.99, repectively. This characteristic fatty acid-based method provided a distinct way to quantify TAGs in microalgae, by which TAGs could be measured precisely by immediate transesterification from wet biomass rather than using conventional methods. This procedure simplified the operation and required smaller samples than conventional methods.

  20. 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.

  1. Suplementaci??n de la dieta de ovejas lecheras con aceite de girasol y l??pidos marinos para modificar la composici??n de la grasa de la leche: efecto sobre el rendimiento productivo de los animales, la microbiota y las caracter??sticas de la fermentaci??n ruminal y el perfil de ??cidos grasos de la leche y la digesta

    OpenAIRE

    Guti??rrez Toral, Pablo

    2011-01-01

    214 p. Se han realizado cinco experimentos con ovejas, con el objetivo de investigar el efecto de la suplementaci??n con aceite de girasol y, o bien aceite de pescado, o bien microalgas marinas, sobre la composici??n de los ??cidos grasos de la leche y la digesta, la micriobiota, la fermantaci??n ruminal y el rendimiento productivo de los animales

  2. 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 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.

  3. VIABILIDADE DE BACTÉRIAS LÁTICAS EM IOGURTE ADICIONADO DE BIOMASSA DA MICROALGA Spirulina platensis DURANTE O ARMAZENAMENTO REFRIGERADO

    Directory of Open Access Journals (Sweden)

    K. J. PEREZ

    2008-11-01

    Full Text Available

    A influência de longos períodos de estocagem sobre a contagem de bactérias láticas viáveis tem sido estudada, uma vez que os produtos lácteos fermentados devem possuir um número mínimo de microrganismos, a partir do qual apresentam efeitos benéficos ao consumidor. A adição de biomassa seca da microalga Spirulina platensis pode influenciar beneficamente a sobrevivência das bactérias iniciadoras durante o armazenamento refrigerado, devido à sua composição em proteínas, vitaminas, aminoácidos essenciais, minerais e ácidos graxos essenciais como ácido - linolênico. Objetivou-se avaliar a viabilidade celular das bactérias láticas sob refrigeração em iogurtes preparados com e sem a adição de extrato seco da microalga Spirulina. O iogurte foi elaborado sob condições assépticas e dividido em três amostras: controle, com adição de 0,5 e 1,0 % de biomassa da microalga Spirulina seca. Estas amostras foram armazenadas a 4ºC durante 0, 15 e 30 dias, sendo realizadas contagens de bactérias láticas nestes períodos. A adição de biomassa de Spirulina platensis influenciou positivamente a sobrevivência das bactérias ácido-láticas durante o armazenamento refrigerado, diminuindo a perda de viabilidade durante os 30 dias de armazenamento refrigerado para as amostras adicionadas de 1,0 % de biomassa de Spirulina platensis.

  4. 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.

  5. Bacterial Influence on Alkenones in Live Microalgae1

    Science.gov (United States)

    Segev, Einat; Castañeda, Isla S.; Sikes, Elisabeth L.; Vlamakis, Hera; Kolter, Roberto

    2015-01-01

    The microalga Emiliania huxleyi produces alkenone lipids which are important proxies for estimating past sea surface temperatures. Field calibrations of this proxy are robust but highly variable results are obtained in culture. Here we present results suggesting that algal-bacterial interactions may be responsible for some of this variability. Co-cultures of E. huxleyi and the bacterium Phaeobacter inhibens resulted in a 2.5-fold decrease in algal alkenone-containing lipid bodies. In addition levels of unsaturated alkenones increase in co-cultures. These changes result in an increase in the reconstructed growth temperature of up to 2°C relative to axenic algal cultures. PMID:26987094

  6. Rationales and Approaches for Studying Metabolism in Eukaryotic Microalgae

    Directory of Open Access Journals (Sweden)

    Daniel Veyel

    2014-04-01

    Full Text Available The generation of efficient production strains is essential for the use of eukaryotic microalgae for biofuel production. Systems biology approaches including metabolite profiling on promising microalgal strains, will provide a better understanding of their metabolic networks, which is crucial for metabolic engineering efforts. Chlamydomonas reinhardtii represents a suited model system for this purpose. We give an overview to genetically amenable microalgal strains with the potential for biofuel production and provide a critical review of currently used protocols for metabolite profiling on Chlamydomonas. We provide our own experimental data to underpin the validity of the conclusions drawn.

  7. Microalgae biorefinery symbiosis: screening, production, and process analytical technology

    DEFF Research Database (Denmark)

    Podevin, Michael Paul Ambrose

    advances in hardware and software can significantly improve microalgal bioprocess models and automation, by manipulating large, time-resolute data sets, so-called “big data,” which can be acquired through high-selectivity vibrational spectroscopy, such as mid-infrared (MIR), near-infrared (NIR), or Raman...... is becoming increasingly necessary and beneficial to microalgae production in an MBS. The focus of this thesis is to bring together lab-scale demonstrations, scaled up knowledge, and a critical outlook of modern technologies capable of making the MBS a reality....

  8. Microalgae downstream processing and economical approaches of biodiesel producton processes

    OpenAIRE

    Ríos, Sergio Daniel

    2013-01-01

    Durante las últimas décadas, se ha prestado mucha atención a la producción de biodiesel a partir de microalgas (alta productividad y contenido lipídico). Sin embargo la viabilidad de su producción depende del proceso global y la optimización de cada una de las etapas del proceso. El presente trabajo combina una serie de propuestas de optimización de los procesos post-cultivos demostrados a escala piloto (concentración mediante filtración-dinámica y extracción/transesterificación directa de lí...

  9. Evaluation of microalgae production coupled with wastewater treatment

    DEFF Research Database (Denmark)

    De Francisci, Davide; Su, Yixi; Iital, Arvo

    2017-01-01

    In the present study the feasibility of microalgae production coupled with wastewater treatment was assessed. Continuous cultivation of Chlorella sorokiniana with wastewater was tested in lab-scale flat panel photobioreactors. Biomass productivity was determined for four dilution rates (4.32 d-1, 3...... that potentially more than 70% of revenue was from the production of pigments, i.e. chlorophyllin (59.6%), lutein (8.9%) and β-carotene (5.0%) while reduction in discharging costs of the treated wastewaters could account for 19.6% of the revenue. Due to the low yield of FAME and the low market price of biodiesel...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    M. E. Ramírez

    2017-10-01

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

  12. Integral microalgae-bacteria model (BIO_ALGAE): Application to wastewater high rate algal ponds.

    Science.gov (United States)

    Solimeno, Alessandro; Parker, Lauren; Lundquist, Tryg; García, Joan

    2017-12-01

    An integral mechanistic model describing the complex interactions in mixed algal-bacterial systems was developed. The model includes crucial physical, chemical and biokinetic processes of microalgae as well as bacteria in wastewater. Carbon-limited microalgae and autotrophic bacteria growth, light attenuation, photorespiration, temperature and pH dependency are some of the new features included. The model named BIO_ALGAE was built using the general formulation and structure of activated sludge models (ASM), and it was implemented in COMSOL Multiphysics™ platform. Calibration and validation were conducted with experimental data from two identical pilot HRAPs receiving real wastewater. The model was able to simulate the dynamics of different components in the ponds, and to predict the relative proportion of microalgae (58-68% in average of total suspended solids (TSS) and bacteria (30-20% in average of TSS). Microalgae growth resulted strongly influenced by the light factor f L (I), decreasing microalgae concentrations from 40 to 60%. Furthermore, reducing the influent organic matter concentration of 50% and 70%, model predictions indicated that microalgae production increased from (8.7gTSSm -2 d -1 to 13.5gTSSm -2 d -1 ) due to the new distribution of particulate components. The proposed model could be an efficient tool for industry to predict the production of microalgae, as well as to design and optimize HRAPs. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Impact of Microalgae-Bacteria Interactions on the Production of Algal Biomass and Associated Compounds

    Directory of Open Access Journals (Sweden)

    Juan Luis Fuentes

    2016-05-01

    Full Text Available A greater insight on the control of the interactions between microalgae and other microorganisms, particularly bacteria, should be useful for enhancing the efficiency of microalgal biomass production and associated valuable compounds. Little attention has been paid to the controlled utilization of microalgae-bacteria consortia. However, the studies of microalgal-bacterial interactions have revealed a significant impact of the mutualistic or parasitic relationships on algal growth. The algal growth, for instance, has been shown to be enhanced by growth promoting factors produced by bacteria, such as indole-3-acetic acid. Vitamin B12 produced by bacteria in algal cultures and bacterial siderophores are also known to be involved in promoting faster microalgal growth. More interestingly, enhancement in the intracellular levels of carbohydrates, lipids and pigments of microalgae coupled with algal growth stimulation has also been reported. In this sense, massive algal production might occur in the presence of bacteria, and microalgae-bacteria interactions can be beneficial to the massive production of microalgae and algal products. This manuscript reviews the recent knowledge on the impact of the microalgae-bacteria interactions on the production of microalgae and accumulation of valuable compounds, with an emphasis on algal species having application in aquaculture.

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

    Science.gov (United States)

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

    2011-09-01

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

  15. 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.

  16. 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.

    2015-01-01

    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. PMID:26221091

  17. Progress in microalgae cultivation photobioreactors and applications in wastewater treatment: A review

    Directory of Open Access Journals (Sweden)

    Lu Haifeng

    2017-01-01

    Full Text Available Using microalgae to treat wastewater has received growing attention in the world because it is regarded as a novel means for wastewater treatment. It is commonly recognized that large-scale cultivation and commercial application of microalgae are limited by the development of photobioreactor (PBR. Although there are a lot of PBRs for microalgae pure cultivation which used culture medium, specialized PBRs designed for wastewater treatment are rare. The composition of wastewater is quite complicated; this might cause a very different photosynthetic effect of microalgae compared to those grown in a pure cultivation medium. Therefore, PBRs for wastewater treatment need to be redesigned and improved based on the existing PBRs that are used for microalgae pure cultivation. In this review, different PBRs for microalgae cultivation and wastewater treatment are summarized. PBR configurations, PBR design parameters and types of wastewater are presented. In addition, the wastewater treatment efficiency and biomass productivity were also compared among each type of PBRs. Moreover, some other promising PBRs are introduced in this review, and a two-stage cultivation mode which combines both closed and open system is discussed as well. Ultimately, this article focuses on current problems and gives an outlook for this field, aiming at providing a primary reference for microalgae cultivation by using wastewater.

  18. Purification of microalgae from bacterial contamination using a disposable inertia-based microfluidic device

    Science.gov (United States)

    Godino, Neus; Jorde, Felix; Lawlor, Daryl; Jaeger, Magnus; Duschl, Claus

    2015-08-01

    Microalgae are a promising source of bioactive ingredients for the food, pharmaceutical and cosmetic industries. Every microalgae research group or production facility is facing one major problem regarding the potential contamination of the algal cell with bacteria. Prior to the storage of the microalgae in strain collections or to cultivation in bioreactors, it is necessary to carry out laborious purification procedures to separate the microalgae from the undesired bacterial cells. In this work, we present a disposable microfluidic cartridge for the high-throughput purification of microalgae samples based on inertial microfluidics. Some of the most relevant microalgae strains have a larger size than the relatively small, few micron bacterial cells, so making them distinguishable by size. The inertial microfluidic cartridge was fabricated with inexpensive materials, like pressure sensitive adhesive (PSA) and thin plastic layers, which were patterned using a simple cutting plotter. In spite of fabrication restrictions and the intrinsic difficulties of biological samples, the separation of microalgae from bacteria reached values in excess of 99%, previously only achieved using conventional high-end and high cost lithography methods. Moreover, due to the simple and high-throughput characteristic of the separation, it is possible to concatenate serial purification to exponentially decrease the absolute amount of bacteria in the final purified sample.

  19. Impact of Microalgae-Bacteria Interactions on the Production of Algal Biomass and Associated Compounds.

    Science.gov (United States)

    Fuentes, Juan Luis; Garbayo, Inés; Cuaresma, María; Montero, Zaida; González-Del-Valle, Manuel; Vílchez, Carlos

    2016-05-19

    A greater insight on the control of the interactions between microalgae and other microorganisms, particularly bacteria, should be useful for enhancing the efficiency of microalgal biomass production and associated valuable compounds. Little attention has been paid to the controlled utilization of microalgae-bacteria consortia. However, the studies of microalgal-bacterial interactions have revealed a significant impact of the mutualistic or parasitic relationships on algal growth. The algal growth, for instance, has been shown to be enhanced by growth promoting factors produced by bacteria, such as indole-3-acetic acid. Vitamin B12 produced by bacteria in algal cultures and bacterial siderophores are also known to be involved in promoting faster microalgal growth. More interestingly, enhancement in the intracellular levels of carbohydrates, lipids and pigments of microalgae coupled with algal growth stimulation has also been reported. In this sense, massive algal production might occur in the presence of bacteria, and microalgae-bacteria interactions can be beneficial to the massive production of microalgae and algal products. This manuscript reviews the recent knowledge on the impact of the microalgae-bacteria interactions on the production of microalgae and accumulation of valuable compounds, with an emphasis on algal species having application in aquaculture.

  20. 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.

  1. EVALUACIÓN DEL EFECTO DEL HIDROCARBURO FENANTRENO SOBRE EL CRECIMIENTO DE Chlorella vulgaris (CHLORELLACEAE

    Directory of Open Access Journals (Sweden)

    ANGÉLICA OTERO-PATERNINA

    2013-01-01

    Full Text Available Se evaluó el efecto del hidrocarburo policíclico aromático fenantreno sobre el creci- miento de la microalga Chlorella vulgaris bajo condiciones de laboratorio. Las microalgas fueron expuestas a diferentes concentraciones de fenantreno (0, 1, 10, 100, 1000 y 10000 μg/l. El tiempo de exposición fue de 72 h, determinándose diariamente la den- sidad algal mediante recuento en cámara de Neubauer. Se determinó la tasa promedio de crecimiento, la biomasa total y el porcentaje de inhibición de la biomasa. También se evaluó el contenido de clorofila a, al inicio y final del experimento. Los ensayos fueron realizados en recipientes de vidrio de 0,4 l, utilizando como medio de cultivo fertilizante inorgánico del complejo NPK (REMITAL® m – 17-6-18 a razón de 1 g/l. Los resultados mostraron que el fenantreno inhibió progresivamente el crecimiento de la microalga, observándose el menor crecimiento celular en el medio con la mayor concentración de fenantreno, el cual alcanzó un porcentaje de inhibición del crecimiento del 59 %. Las ta- sas de crecimiento diario se mantuvieron relativamente constantes en los demás trata- mientos. La concentración de clorofila a, medida mediante espectrofotometría, no se afectó por las diferentes concentraciones del hidrocarburo. En conclusión, el crecimiento de la microalga C. vulgaris puede afectarse negativamente por la exposición a concentra- ciones nominales superiores a 1 μg/l de fenantreno.

  2. [Identification of Microalgae Species Using Visible/Near Infrared Transmission Spectroscopy].

    Science.gov (United States)

    Zhu, Hong-yan; Shao, Yong-ni; Jiang, Lu-lu; Guo, An-que; Pan, Jian; He, Yong

    2016-01-01

    At present, the identification and classification of the microalgae and its biochemical analysis have become one of the hot spots on marine biology research. Four microalgae species, including Chlorella vulgaris, Chlorella pyrenoidosa, Nannochloropsis oculata, Chlamydomonas reinhardtii, were chosen as the experimental materials. Using an established spectral acquisition system, which consists of a portable USB 4000 spectrometer having transmitting and receiving fiber bundles connected by a fiber optic probe, a halogen light source, and a computer, the Vis/NIR transmission spectral data of 120 different samples of the microalgae with different concentration gradients were collected, and the spectral curves of fourmicroalgae species were pre-processed by different pre-treatment methods (baseline filtering, convolution smoothing, etc. ). Based on the pre-treated effects, SPA was applied to select effective wavelengths (EWs), and the selected EWs were introduced as inputs to develop and compare PLS, Least Square Support Vector Machines (LS-SVM), Extreme Learning Machine (ELM)models, so as to explore the feasibility of using Vis/NIR transmission spectroscopy technology for the rapid identification of four microalgae species in situ. The results showed that: the effect of Savitzky-Golay smoothing was much better than the other pre-treatment methods. Six EWs selected in the spectraby SPA were possibly relevant to the content of carotenoids, chlorophyll in the microalgae. Moreover, the SPA-PLS model obtained better performance than the Full-Spectral-PLS model. The average prediction accuracy of three methods including SPA-LV-SVM, SPA-ELM, and SPA-PLS were 80%, 85% and 65%. The established method in this study may identify four microalgae species effectively, which provides a new way for the identification and classification of the microalgae species. The methodology using Vis/NIR spectroscopy with a portable optic probe would be applicable to a diverse range of microalgae

  3. Microalgae of the continental shelf off Paraná State, southeastern Brazil: a review of studies

    Directory of Open Access Journals (Sweden)

    Frederico P. Brandini

    1996-01-01

    Full Text Available The paper reviews the taxonomic and ecological works on marine microalgae (phytoplankton and microphytobenthos off Paraná State, Southeastern Brazil. Various studies refer to the taxonomy of benthic diatoms. Few descriptive field works in coastal and adjacent shelf waters contribute to the understanding of phytoplankton dynamics in coastal and shelf areas. Patterns of geographic distribution and changes in the phytoplankton community are described in relation to water masses and seasonal variations in the hydrographic regime. During summertime, when warm oligotrophic waters predominate over the shelf, the phytoplankton is nummerically dominated by small phytotlagellates, dinotlagellates, coccolithophorids and filaments of cyanobacteria. During wintertime, the abundance of micro-size diatoms over the shclf increase due to the dominance of cold nutrient-rich waters from the South Atlantic Central Water and wind-driven vertical circulation. The phytoplankton community off Paraná State may be classified into two categorics: the diatom-dominated coastal assemblage, mainly controlled by nutrient inputs from land drainage and ressuspension of bottom sediments, and the tlagellate-dominated shelf assemblage, more affectcd by the seasonality of local hydrographic regime.O trabalho é uma revisão dos estudos taxonômicos e ecológicos das microalgas (planctônicas e bentônicas realizados no Estado do Paraná. A maioria dos trabalhos sobre microfitobentos são de caráter taxonômico e, basicamente, referem-se à diatomáceas bênticas sobre macroalgas ou fundos lodosos e consolidados. Poucos trabalhos contribuiram para o estudo da dinâmica espaço-temporal do fitoplâncton em áreas costeiras e de plataforma. São descritos os padrões de distribuição geográfica e as mudanças sazonais na comunidade fitoplanctônica em relação ao regime hidrográfico. No verão, quando águas quentes oligotróficas predominam na superfície, o fitoplâncton

  4. Optimizing carbon dioxide utilization for microalgae biofilm cultivation.

    Science.gov (United States)

    Blanken, Ward; Schaap, Stefan; Theobald, Sophie; Rinzema, Arjen; Wijffels, René H; Janssen, Marcel

    2017-04-01

    The loss of carbon dioxide (CO2 ) to the environment during microalgae cultivation is undesirable for both environmental and economic reasons. In this study, a phototrophic biofilm growth model was developed and validated with the objective to maximize both CO2 utilization efficiency and production of microalgae in biofilms. The model was validated in growth experiments with CO2 as the limiting substrate. The CO2 utilization and biomass productivity were maximized by changing the gas flow rate, the number of biofilm reactors in series and gas composition. Based on simulations, the maximum CO2 utilization efficiency that was reached was 96% based on a process employing flue gas. The corresponding drop in productivity was only 2% in comparison to the non-CO2 limited reference situation. In order to achieve this, 25 biofilm reactors units, or more, must be operated in series. Based on these results, it was concluded that concentrated CO2 streams and plug flow behavior of the gaseous phase over the biofilm surface are essential for high productivity and CO2 utilization efficiency. Biotechnol. Bioeng. 2017;114: 769-776. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Cultivating Microalgae in Domestic Wastewater for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Soha S.M. MOSTAFA

    2012-02-01

    Full Text Available The objective of this study was to evaluate the growth of nine species of microalgae (green and blue green microalgae on domestic waste water samples obtained from Zenein Waste Water Treatment Plant (ZWWTP, Giza governorate, Egypt. The species were cultivated in different kind of waste water; before treatment; after sterilization; with nutrients with sterilization and with nutrients without sterilization. The experiment was conducted in triplicate and cultures were incubated at 251C under continuous shaking (150 rpm and illumination (2000 Lux for 15 days. pH, electric conductivity (EC, optical density (OD , dry weight (DW, were done at the time of incubation and at the end of experiment, in addition to determine the percentage of lipid and biodiesel. The data revealed that, domestic waste water with nutrient media (T3 was promising for cultivation of five algal species when compared with conventional media, Moreover, domestic waste water after sterilization (T2 was selected media for cultivation of Oscillatoria sp and Phormedium sp. However, T1 media (waste water without treatment was the promising media for cultivation of Nostoc humifusum. The biodiesel produced from algal species cultivated in waste water media ranged from 3.8 to 11.80% when compared with the conventional method (3.90 to 12.52%. The results of this study suggest that growing algae in nutrient rich media offers a new option of applying algal process in ZWWTP to mange the nutrient load for growth and valuable biodiesel feedstock production.

  6. Effective harvesting of microalgae by coagulation–flotation

    Science.gov (United States)

    Xia, Ling; Li, Yinta; Huang, Rong

    2017-01-01

    This study developed a coagulation–flotation process for microalgae Chlorella sp. XJ-445 harvesting, which was composed of algal surface modification by combined use of Al3+ and cetyltrimethylammonium bromide (CTAB) and followed dispersed bubble flotation. Dissolved organic matter (DOM) in the medium was firstly characterized and mainly consisted of hydrophilic low molecular weight molecules. The dosage of collector (CTAB) and coagulant (Al3+) were optimized, and with the pretreatment of 40 mg Al3+ and 60 mg CTAB per 1 g dry biomass without pH adjustment, a maximum flotation recovery efficiency of 98.73% can be achieved with the presence of DOM. Algal cells characterization results showed that the combined use of CTAB and Al3+ largely enhanced the algal floc size, and exhibited higher degree of hydrophobicity, which favoured the flotation, and can be interpreted by DLVO (Derjaguin, Landau, Verwey and Overbeek) modelling. A benefit in fatty acid conversion was further found with the optimized coagulation–flotation process. It was suggested that this coagulation based flotation is a promising strategy for high-efficiency harvesting of microalgae. PMID:29291079

  7. Lipid extraction methods from microalgae: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Ranjith Kumar eR

    2015-01-01

    Full Text Available Energy security has become a serious global issue and a lot of research is being carried out to look for economocially viable and environment-friendly alternatives. The only solution that appears to to meet the futuristic needs is the use of renewable energy. Although various forms of renewable energy are being currently used, the prospects of producing carbon-neutral biofuels from microalgae appears bright because of its unique features such as suitability of growing in open ponds required for production of a commodity product, high CO2-sequestering capability, ability to grow in wastewater/seawater/brackishwater and high lipid productivity. The major process constraint in the microalgal biofuel technology is the cost-effective and efficient extraction of lipids. The objective of this article is to provide a comprehensive review on various methods of lipid extraction from microalgae available till date, as well as to discuss their advantages and disadvantages. The article covers all areas of lipid extraction procedures including solvent extraction procedures, mechanical approaches and solvent-free procedures apart from some of the latest extraction technologies. A lot more research efforts are required in this area for successful implementation of this technology at a production scale.

  8. Investigation of optimal condition for Chlorella vulgaris microalgae growth

    Directory of Open Access Journals (Sweden)

    S. Daliry

    2017-03-01

    Full Text Available Due to its abundance and also flexibility of cultivation conditions, Chlorella vulgaris microalgae is one of the most ideal options available in order to production of microalgae based biodiesel. Since vulgaris cultivation for fuel production needs economic considerations to be taken, and in first place providing biomass and lipid production costs is important, wide researches have been conducted in this field, and this study aims to spot the best condition for cultivation of this valuable specie by reviewing the whole research conducted. So far, Researchers' efforts show that, the best condition for vulgaris cultivation is mixotrophic regime which is done in a bubble column photobioreactor. Glucose as carbonic source and nitrate as nitrogen source, have the most efficacy among nutrition conditions. It is known the best results obtain in amounts glucose and nitrate of 20 and o.5 g/L respectively. Alkaline medium (pH 9 to 10, non-continuous illumination, 5 to 7 Klux and a 200 mL/min aeration flow rate, indicated the best physical conditions. The most vulgaris biomass amount produced was 3.43 g/L, and the best lipid productivity was measured 66.25 mg/L/day.

  9. Phycoremediation of Tannery Wastewater Using Microalgae Scenedesmus Species.

    Science.gov (United States)

    Ajayan, Kayil Veedu; Selvaraju, Muthusamy; Unnikannan, Pachikaran; Sruthi, Palliyath

    2015-01-01

    A number of microalgae species are efficient in removing toxicants from wastewater. Many of these potential species are a promising, eco-friendly, and sustainable option for tertiary wastewater treatment with a possible advantage of improving the economics of microalgae cultivation for biofuel production. The present study deals with the phycoremediation of tannery wastewater (TWW) using Scenedesmus sp. isolated from a local habitat. The test species was grown in TWW under laboratory conditions and harvested on the 12th day. The results revealed that the algal biomass during the growth period not only reduced the pollution load of heavy metals (Cr-81.2-96%, Cu-73.2-98%, Pb-75-98% and Zn-65-98%) but also the nutrients (NO3 >44.3% and PO4 >95%). Fourier Transform Infrared (FTIR) spectrums of Scenedesmus sp. biomass revealed the involvement of hydroxyl amino, carboxylic and carbonyl groups. The scanning electron micrograph (SEM) and Energy Dispersive X-ray Spectroscopic analysis (EDS) revealed the surface texture, morphology and element distribution of the biosorbent. Furthermore, the wastewater generated during wet-blue tanning process can support dense population of Scenedesmus sp., making it a potential growth medium for biomass production of the test alga for phycoremediation of toxicants in tannery wastewaters.

  10. Harvesting of microalgae cell using oxidized dye wastewater.

    Science.gov (United States)

    Seo, Yeong Hwan; Park, Doyoung; Oh, You-Kwan; Yoon, Sukhwan; Han, Jong-In

    2015-09-01

    In this study, oxidized dye wastewaters were tested for their potential to be used as a cheap coagulant for microalgae harvesting. Two dyes (methylene blue (MB) and methyl orange (MO)) were selected as model dyes, and the Fenton-like reaction under high temperature (90 °C, 1 min) employed as an oxidative treatment option. A maximum harvesting efficiency over 90% was obtained with both MB and MO at a dilution ratio of 5:1 (dye wastewater: cell culture), when the optimal oxidation condition was 20 mg/L of dye, 1 mM of FeCl3, and 0.5% of H2O2 concentration. This phenomenon could be explained by the possibility that amine groups are formed and exposed in oxidized dyes, which act as a kind of amine-based coagulant just like chitosan. This study clearly showed that dye wastewater, when properly oxidized, could serve as a potent coagulant for microalgae harvesting, potentially rendering the harvesting cost reduced to a substantial degree. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Microalgae and Its Premises towards Sustainable Energy Development

    Science.gov (United States)

    Chik, M. N.; Yahya, L.; Zainal, A.; Boosroh, M. H.

    2017-06-01

    This paper features the use of nature’s element as a tool to combat current global issues on environment. Through research works by TNB Research Sdn. Bhd. (TNBR), marine phototrophic microalgae is used in reducing CO2 emissions from its fossil-fuel based power plants using. The research program commenced in 2011 with the aim to develop capacity, capability and facilities in biological CO2 fixation. The research program focuses on improving and enhancing the CO2 fixation through four core measures; namely species selection, nutrient optimization, flue gas admission and photobioreactor (PBR) design and engineering. The measures lead to the migration and evolution of culture facilities from laboratory conditions to outdoor, from shake flasks to 6 x 250 liter pilot PBR facility at a live coal-fired power plant, from mono species to consortium of species. Increment of CO2 fixation rates is summarized with discussion on comparisons of other achievements reported elsewhere. A considerable amount of work on analysing the bioactive compound present in the algae - protein, amino acids, carbohydrate, lipid, fatty acids - and its encouraging results, as an impetus towards sustainable development, will also be shared. Premises and observations from various microalgae research works are collated and presented in a manner sufficient to highlight the eminent roles of this tiny creature to become our mentor in providing some solutions to our worldly problems.

  12. 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%. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Paracetamol and salicylic acid removal from contaminated water by microalgae.

    Science.gov (United States)

    Escapa, C; Coimbra, R N; Paniagua, S; García, A I; Otero, M

    2017-12-01

    The biomass growth, pharmaceutical removal and light conversion efficiency of Chlorella sorokiniana under the presence of paracetamol (PC) and salicylic acid (SaC) were assessed and compared at two different concentrations of these pharmaceuticals (I: 25 mg l-1, II: 250 mg l-1). Microalgae were resistant to these concentrations and, moreover, their growth was significantly stimulated (p ≤ 0.05) under these drugs (biomass concentration increased above 33% PCI, 35% SaCI, 13% PCII and 45% SaCII, as compared with the respective positive controls). At the steady state of the semicontinuous culture, C. sorokiniana showed removal efficiencies above 41% and 69% for PCI and PCII, respectively; and above 93% and 98% for SaCI and SaCII, respectively. Under an irradiance of 370 μE m-2 s-1, higher quantum yields were reached by microalgae under the presence of drugs, either at dose I or II, than by the respective positive controls. These results point to C. sorokiniana as a robust strain for the bioremediation of paracetamol and salicylic acid concentrated wastewaters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. 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

  17. 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)

  18. 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)

  19. Cultivating Microalgae in Domestic Wastewater for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Soha S.M. MOSTAFA

    2012-02-01

    Full Text Available The objective of this study was to evaluate the growth of nine species of microalgae (green and blue green microalgae on domestic waste water samples obtained from Zenein Waste Water Treatment Plant (ZWWTP, Giza governorate, Egypt. The species were cultivated in different kind of waste water; before treatment; after sterilization; with nutrients with sterilization and with nutrients without sterilization. The experiment was conducted in triplicate and cultures were incubated at 25�1�C under continuous shaking (150 rpm and illumination (2000 Lux for 15 days. pH, electric conductivity (EC, optical density (OD , dry weight (DW, were done at the time of incubation and at the end of experiment, in addition to determine the percentage of lipid and biodiesel. The data revealed that, domestic waste water with nutrient media (T3 was promising for cultivation of five algal species when compared with conventional media, Moreover, domestic waste water after sterilization (T2 was selected media for cultivation of Oscillatoria sp and Phormedium sp. However, T1 media (waste water without treatment was the promising media for cultivation of Nostoc humifusum. The biodiesel produced from algal species cultivated in waste water media ranged from 3.8 to 11.80% when compared with the conventional method (3.90 to 12.52%. The results of this study suggest that growing algae in nutrient rich media offers a new option of applying algal process in ZWWTP to mange the nutrient load for growth and valuable biodiesel feedstock production.

  20. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    2011-01-01

    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. PMID:22047615

  2. Development of a biosensor for environmental monitoring based on microalgae immobilized in silica hydrogels.

    Science.gov (United States)

    Ferro, Yannis; Perullini, Mercedes; Jobbagy, Matias; Bilmes, Sara A; Durrieu, Claude

    2012-12-06

    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.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Yu Wei-Luen

    2011-11-01

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

  6. Nuclear Engineering of Microalgae for High Yield Secretion of Recombinant Proteins

    DEFF Research Database (Denmark)

    Ramos Martinez, Erick Miguel

    Photosynthetic microorganism like microalgae and cyanobacteria are considered as emerging biotechnology platforms for production of recombinant proteins and other high-value biomolecules with a wide range of applications. Moreover, microalgae offer significant advantages compared with other...... the potential of microalgae as a cell factory for secretion of recombinant proteins. The second research project presented in this thesis aimed to establish a new robust method to allow in vivo measurements of metabolic enzyme activities in cyanobacteria, with a hope that the method would facilitate further...

  7. 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.

  8. 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.

  9. 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

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

    Directory of Open Access Journals (Sweden)

    Silvana Ohse

    2009-09-01

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

  11. Rapid Characterization of Microalgae and Microalgae Mixtures Using Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS).

    Science.gov (United States)

    Barbano, Duane; Diaz, Regina; Zhang, Lin; Sandrin, Todd; Gerken, Henri; Dempster, Thomas

    2015-01-01

    Current molecular methods to characterize microalgae are time-intensive and expensive. Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) may represent a rapid and economical alternative approach. The objectives of this study were to determine whether MALDI-TOF MS can be used to: 1) differentiate microalgae at the species and strain levels and 2) characterize simple microalgal mixtures. A common protein extraction sample preparation method was used to facilitate rapid mass spectrometry-based analysis of 31 microalgae. Each yielded spectra containing between 6 and 56 peaks in the m/z 2,000 to 20,000 range. The taxonomic resolution of this approach appeared higher than that of 18S rDNA sequence analysis. For example, two strains of Scenedesmus acutus differed only by two 18S rDNA nucleotides, but yielded distinct MALDI-TOF mass spectra. Mixtures of two and three microalgae yielded relatively complex spectra that contained peaks associated with members of each mixture. Interestingly, though, mixture-specific peaks were observed at m/z 11,048 and 11,230. Our results suggest that MALDI-TOF MS affords rapid characterization of individual microalgae and simple microalgal mixtures.

  12. Rapid Characterization of Microalgae and Microalgae Mixtures Using Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS)

    Science.gov (United States)

    Barbano, Duane; Diaz, Regina; Zhang, Lin; Sandrin, Todd; Gerken, Henri; Dempster, Thomas

    2015-01-01

    Current molecular methods to characterize microalgae are time-intensive and expensive. Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) may represent a rapid and economical alternative approach. The objectives of this study were to determine whether MALDI-TOF MS can be used to: 1) differentiate microalgae at the species and strain levels and 2) characterize simple microalgal mixtures. A common protein extraction sample preparation method was used to facilitate rapid mass spectrometry-based analysis of 31 microalgae. Each yielded spectra containing between 6 and 56 peaks in the m/z 2,000 to 20,000 range. The taxonomic resolution of this approach appeared higher than that of 18S rDNA sequence analysis. For example, two strains of Scenedesmus acutus differed only by two 18S rDNA nucleotides, but yielded distinct MALDI-TOF mass spectra. Mixtures of two and three microalgae yielded relatively complex spectra that contained peaks associated with members of each mixture. Interestingly, though, mixture-specific peaks were observed at m/z 11,048 and 11,230. Our results suggest that MALDI-TOF MS affords rapid characterization of individual microalgae and simple microalgal mixtures. PMID:26271045

  13. Combined extraction processes of lipid from Chlorella vulgaris microalgae: microwave prior to supercritical carbon dioxide extraction

    National Research Council Canada - National Science Library

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

    2011-01-01

    ...) allowed to obtain the highest extraction yield (4.73%) compared to SCCO(2) extraction alone (1.81%). Qualitative and quantitative analyses of microalgae oil showed that palmitic, oleic, linoleic...

  14. A state of the art of metabolic networks of unicellular microalgae and cyanobacteria for biofuel production.

    Science.gov (United States)

    Baroukh, Caroline; Muñoz-Tamayo, Rafael; Steyer, Jean-Philippe; Bernard, Olivier

    2015-07-01

    The most promising and yet challenging application of microalgae and cyanobacteria is the production of renewable energy: biodiesel from microalgae triacylglycerols and bioethanol from cyanobacteria carbohydrates. A thorough understanding of microalgal and cyanobacterial metabolism is necessary to master and optimize biofuel production yields. To this end, systems biology and metabolic modeling have proven to be very efficient tools if supported by an accurate knowledge of the metabolic network. However, unlike heterotrophic microorganisms that utilize the same substrate for energy and as carbon source, microalgae and cyanobacteria require light for energy and inorganic carbon (CO2 or bicarbonate) as carbon source. This double specificity, together with the complex mechanisms of light capture, makes the representation of metabolic network nonstandard. Here, we review the existing metabolic networks of photoautotrophic microalgae and cyanobacteria. We highlight how these networks have been useful for gaining insight on photoautotrophic metabolism. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2014-11-01

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

  16. Molecular characterization of CO2 sequestration and assimilation in microalgae and its biotechnological applications.

    Science.gov (United States)

    Zhu, Baojun; Chen, Gu; Cao, Xupeng; Wei, Dong

    2017-11-01

    Microalgae are renewable feedstock for sustainable biofuel production, cell factory for valuable chemicals and promising in alleviation of greenhouse gas CO2. However, the carbon assimilation capacity is still the bottleneck for higher productivity. Molecular characterization of CO2 sequestration and assimilation in microalgae has advanced in the past few years and are reviewed here. In some cyanobacteria, genes for 2-oxoglytarate dehydrogenase was replaced by four alternative mechanisms to fulfill TCA cycle. In green algae Coccomyxa subellipsoidea C-169, alternative carbon assimilation pathway was upregulated under high CO2 conditions. These advances thus provide new insights and new targets for accelerating CO2 sequestration rate and enhancing bioproduct synthesis in microalgae. When integrated with conventional parameter optimization, molecular approach for microalgae modification targeting at different levels is promising in generating value-added chemicals from green algae and cyanobacteria efficiently in the near future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. 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

  18. Resistant biomacromolecules in five marine microalgae of the classes Eustigmatophyceae and Chlorophyceae: Geochemical implications

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Gelin, F.; Boogers, I.; Noordeloos, A.A.M.; Riegman, R.; Leeuw, J.W. de

    1997-01-01

    Non-hydrolysable macromolecular constituents (i.e. algaenans) were isolated from two out of seven marine microalgae investigated. Nannochloropsis salina and Nannochloropsis sp. from the class of Eustigmatophyceae produce highly aliphatic algaenans. Flash pyrolysis and chemical degradations with HI

  19. 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...

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

    Science.gov (United States)

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

    2017-08-01

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