Effect of Ozone Treatment on Cultures of Nannochloropsis oculata, Isochrysis galbana, and Chaetoceros gracilis

1999 ◽  
Vol 30 (4) ◽  
pp. 473-480 ◽  
Author(s):  
Nasir Kuresity ◽  
D. Allen Davis ◽  
C. R. Arnold
2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Jayasree Loka ◽  
K.K. Philipose ◽  
S.M. Sonali

Effect of marine microalgal diet on filtration and ingestion rates of Brachionus plicatilis was studied. Marine microalgae viz., Nannochloropsis oculata, Isochrysis galbana, Chaetoceros calcitrans and a combination of N. oculata and I. galbana (Nanno+Iso) at different cell concentrations were selected for the experiment and triplicates were maintained for each feed. Significant difference (p<0.05) was observed in the filtration and ingestion rates of B. plicatilis, between the treatments. Peak filtration rate of 12.2x10-5 cells ml-1 ind-1 min-1 was recorded in B. plicatilis fed with Nanno+Iso, followed by I. galbana. Ingestion rate was found to be significantly high (p<0.05) for those fed with C. calcitrans, followed by Nanno+Iso. Filtration rate was significantly high (p<0.05) in rotifers stocked at an initial density of 50 nos. ml-1 fed with Nanno+Iso. The results indicated that a combination of Nanno and Iso is the best suitable microalgal diet for rotifer with peak filtration (12.2x10-5cells ml-1 ind-1 min-1) and ingestion (5.4x10-3 cells ml-1 ind-1 min-1) rates during the first 60 min.


Author(s):  
Rodolfo Patricio Panta Vélez ◽  
Ana Gabriela Macay García ◽  
Ermen Miguel Moncayo Zambrano ◽  
Juan Carlos Vélez Chica

En el presente estudio se evalúa el crecimiento de dos especies de microalgas Chaetoceros gracilis e Isochrysis galbana, con dos tipos de fertilizantes agrícolas, en condiciones de laboratorio, con el propósito de  determinar la densidad celular (cel/mL), tasade crecimiento específica (divisiones/día) y tasa deduplicación (divisiones/día) de  cada especie. Los  bioensayos se realizaron en  tubos  de ensayos de 20 mL y botellas de 500 mL y 1 000 mL utilizando  el medio  de cultivo Guillard F/2 como control (T1) y los fertilizantes agrícolas Complefol -solución  Complefol 5 g/L (T2), y solución  Complefol 10 g/L (T3)- y Stimufol -solución  Stimufol 5 g/L (T4) y solución  10 g/L (T5)-, cada uno con tres réplicas. Durante el estudio no se observó diferencias significativas en las densidades celulares, no así  en la tasa de crecimiento específico y tiempo de duplicación en ambos cultivos de microalgas, mostrándose que las mayores densidades celulares, crecimiento específico y tasa de duplicación, se obtuvieron en el medio Guillard/F2, seguido del Stimufol, lo que demuestra que los fertilizantes agrícolas son una alternativa adecuada para  usarse en el cultivo de microalgas, en particular  el Stimufol, con mayores rendimientos en comparación con Complefol.  Palabras clave: Densidad celular, medios de cultivo, microalgas, tasa de crecimiento específica, tiempo de duplicación


1989 ◽  
Vol 46 (5) ◽  
pp. 859-862 ◽  
Author(s):  
Thomas C. Chiles ◽  
Peter D. Pendoley ◽  
Roy B. Laughlin Jr.

We examined uptake of tri-n-butyltin (TBT) by three genera of marine microalgae and one genus of cyanobacterium. There was a linear relationship between external concentrations of TBT and cell burdens in the microalgae Nannochloris sp., Chaetoceros gracilis, and the cyanobacterium Synechococcus sp. (PR-6). The relationship between external TBT concentrations and cell TBT burdens was distinctly nonlinear for Isochrysis galbana. Competitive binding experiments showed a decrease of approximately 88% of the total bound radiolabeled TBT to I. galbana in the presence of a 200-fold excess of unlabeled TBT. No significant decrease of bound TBT was observed for Nannochloris sp. These studies demonstrate that either partitioning or binding may control bioaccumulation of TBT by marine phytoplankton.


2009 ◽  
Vol 39 (6) ◽  
pp. 1760-1767 ◽  
Author(s):  
Silvana Ohse ◽  
Roberto Bianchini Derner ◽  
Renata Ávila Ozório ◽  
Maurício Villela Da Costa Braga ◽  
Paulo Cunha ◽  
...  

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.


Author(s):  
Roberto Retamales González ◽  
Patricio Panta Vélez ◽  
José Vélez Cárdenas

El objetivo de esta investigación fue inducir el desove de la Anadara tuberculosa mediante la disminución y aumento de salinidad en condiciones de laboratorio. Los reproductores de estos moluscos se recolectaron en el sitio San Felipe, del cantón San Vicente, en octubre de 2012. Se describe el desarrollo embrionario y larvario de este molusco, obteniendo larva tipo D entre las 16 y 18 horas después del desove. Durante los 17 días del cultivo larvario, las larvas fueron alimentadas con una mezcla de microalgas de Chaetoceros gracilis e Isochrysis galbana, logrando una tasa de crecimiento de 4,755 µm/día. El desarrollo embrionario y larvario de la A. tuberculosa es semejante a las otras especies de moluscos bivalvos. La contaminación por protozoarios y bacteriana fue uno de los principales factores de mortalidad de las larvas, limitando la fase final del cultivo larvario. Palabras clave: Anadara tuberculosa, desarrollo embrionario, cultivo larval, crecimiento, salinidad.


Aquaculture ◽  
2006 ◽  
Vol 260 (1-4) ◽  
pp. 145-150 ◽  
Author(s):  
A.I. Campa-Córdova ◽  
A. Luna-González ◽  
F. Ascencio ◽  
E. Cortés-Jacinto ◽  
C.J. Cáceres-Martínez

2017 ◽  
Vol 82 (5) ◽  
pp. 509-522 ◽  
Author(s):  
Hafsa Ben ◽  
Ismail Ben ◽  
Mariem Garrab ◽  
Raies Aly ◽  
Jonathan Gagnon ◽  
...  

The present work is carried out to evaluate potential applications of aqueous extracts of two microalgae Isochrysis galbana (PEA) and Nannochloropsis oculata (PEB) containing mainly polysaccharides. The monosaccharide composition of microalgal extracts was determined. GC?MS analyses after derivatization show that glucose is the major compound in both microalgae PEA (56.88 %) and PEB (68.23 %). Mannitol (38.8 %) and inositol (20.32 %) are respectively the second major compounds in PEA and PEB. Silylation of monosaccharides allows the determination of sorbitol that attained 3.38 % in PEB. The determination of antioxidant, antimicrobial and cytotoxic properties were also analyzed. Antioxidant activity was evaluated from the DPPH scavenging activity. PEA and PEB show a concentration dependent DPPH?radical scavenging activity. At concentration of 10 mg/mL, both PEA and PEB exhibit an antioxidant activity of 41.45 and 59.07 %, respectively. PEB and PEA are able to inhibit the growth of Gram-negative bacteria, Grampositive bacteria and three Candida species. Cytotoxic activity was evaluated on human HeLa cervical cancer cells. HeLa cell proliferation was totally inhibited after treatment with PEA and PEB (1 mg/mL) and the inhibition was dose dependent (from 0.031 to 1 mg/mL). Their anticholinesterase activity was also investigated against butyrylcholinesterase enzymes. These polysaccharides possess interesting antimicrobial, anticancer and anticholinesterase activities that could represent an additional value for these microalgal products.


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