scholarly journals PRUEBAS DE TOXICIDAD CON ELUTRIADOS DE SEDIMENTO MARINO DE LAS BAHÍAS LOS CHIMUS, TORTUGAS Y CASMA EN PERÚ EMPLEANDO LAS MICROALGAS Isochrysis galbana Y Nannochloropsis oceanica

2021 ◽  
Vol 20 (2) ◽  
pp. 169-177
Author(s):  
Haydeé López ◽  
María Cristina Miglio ◽  
Christian Paredes
Keyword(s):  
Isochrysis Galbana ◽  
Nannochloropsis Oceanica

Se realizaron pruebas de toxicidad con elutriados de sedimentos marinos provenientes de las bahías Los Chimus, Tortugas y Casma, en Perú, empleando las microalgas marinas Isochrysis galbana y Nannochloropsis oceanica. Las muestras de sedimento marino se colectaron en los meses de marzo y agosto de 2016. Estas pruebas de toxicidad se realizaron siguiendo los protocolos estandarizados, mediante pruebas estáticas a 96 h de exposición. Previamente, se determinó la sensibilidad de ambas cepas de microalgas al sulfato de cobre (CuSO4·5H2O) como sustancia de referencia. La Concentración de Inhibición media (CI50) obtenida en este ensayo demostró que I. galbana fue más sensible que N. oceanica. Los elutriados de los sedimentos marinos, provenientes de las zonas de estudio, presentaron diferentes niveles de toxicidad, tales como “no toxicidad” (CI50 = 90% - 100%), “moderada toxicidad” (CI50 = 59% - 81%) y “alta toxicidad” (CI50 < 59%) al emplear la microalga I. galbana; mientras que, para el caso de N. oceanica solo se presentó el de “no toxicidad” (CI50 = 90% - 100%) frente a las mismas muestras de elutriados de sedimentos. Estas pruebas de toxicidad demuestran que la microalga I. galbana detecta diferentes niveles de toxicidad, por lo que se podría emplear para evaluar ambientalmente muestras de sedimento marino como complemento a pruebas químicas, ya que no se discrimina el origen de la toxicidad.

scholarly journals High-throughput insertional mutagenesis reveals novel targets for enhancing lipid accumulation in Nannochloropsis oceanica

2021 ◽  
Author(s):  
Christian Südfeld ◽  
Michal Hubáček ◽  
Daniel Rodrigues Figueiredo ◽  
Mihris I.S. Naduthodi ◽  
John van der Oost ◽  
...  
Keyword(s):  
High Throughput ◽  
Lipid Accumulation ◽  
Insertional Mutagenesis ◽  
Nannochloropsis Oceanica ◽  
Novel Targets

scholarly journals Microalgae as Sustainable Bio-Factories of Healthy Lipids: Evaluating Fatty Acid Content and Antioxidant Activity

Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 357
Author(s):  
Tiago A. Conde ◽  
Bruna F. Neves ◽  
Daniela Couto ◽  
Tânia Melo ◽  
Bruno Neves ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Fatty Acid Content ◽  
Scenedesmus Obliquus ◽  
Food Sources ◽  
Gas Chromatography Mass Spectrometry ◽  
Nannochloropsis Oceanica ◽  
Omega 3 ◽  
Bioactive Lipids ◽  
Food Ingredients

The demand for sustainable and environmentally friendly food sources and food ingredients is increasing, and microalgae are promoted as a sustainable source of essential and bioactive lipids, with high levels of omega-3 fatty acids (ω-3 FA), comparable to those of fish. However, most FA screening studies on algae are scattered or use different methodologies, preventing a true comparison of its content between microalgae. In this work, we used gas-chromatography mass-spectrometry (GC-MS) to characterize the FA profile of seven different commercial microalgae with biotechnological applications (Chlorella vulgaris, Chlorococcum amblystomatis, Scenedesmus obliquus, Tetraselmis chui, Phaeodactylum tricornutum, Spirulina sp., and Nannochloropsis oceanica). Screening for antioxidant activity was also performed to understand the relationship between FA profile and bioactivity. Microalgae exhibited specific FA profiles with a different composition, namely in the ω-3 FA profile, but with species of the same phylum showing similar tendencies. The different lipid extracts showed similar antioxidant activities, but with a low activity of the extracts of Nannochloropsis oceanica. Overall, this study provides a direct comparison of FA profiles between microalgae species, supporting the role of these species as alternative, sustainable, and healthy sources of essential lipids.

scholarly journals Correction to: Cell wall and organelle modifications during nitrogen starvation in Nannochloropsis oceanica F&M-M24

2021 ◽  
Author(s):  
Bianca Roncaglia ◽  
Alessio Papini ◽  
Graziella Chini Zittelli ◽  
Liliana Rodolfi ◽  
Mario R. Tredici
Keyword(s):  
Cell Wall ◽  
Nitrogen Starvation ◽  
Nannochloropsis Oceanica

scholarly journals Cell wall and organelle modifications during nitrogen starvation in Nannochloropsis oceanica F&M-M24

2021 ◽  
Author(s):  
Roncaglia Bianca ◽  
Papini Alessio ◽  
Chini Zittelli Graziella ◽  
Rodolfi Liliana ◽  
Mario R. Tredici
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Lipid Droplets ◽  
Nitrogen Starvation ◽  
Photosynthetic Apparatus ◽  
Ultrastructural Changes ◽  
Total Biomass ◽  
Nannochloropsis Oceanica ◽  
Final Phase ◽  
Cell Functions

AbstractNannochloropsis oceanica F&M-M24 is able to increase its lipid content during nitrogen starvation to more than 50% of the total biomass. We investigated the ultrastructural changes and the variation in the content of main cell biomolecules that accompany the final phase of lipid accumulation. Nitrogen starvation induced a first phase of thylakoid disruption followed by chloroplast macroautophagy and formation of lipid droplets. During this phase, the total amount of proteins decreased by one-third, while carbohydrates decreased by 12–13%, suggesting that lipid droplets were formed by remodelling of chloroplast membranes and synthesis of fatty acids from carbohydrates and amino acids. The change in mitochondrial ultrastructure suggests also that these organelles were involved in the process. The cell wall increased its thickness and changed its structure during starvation, indicating that a disruption process could be partially affected by the increase in wall thickness for biomolecules recovery from starved cells. The wall thickness in strain F&M-M24 was much lower than that observed in other strains of N. oceanica, showing a possible advantage of this strain for the purpose of biomolecules extraction. The modifications following starvation were interpreted as a response to reduction of availability of a key nutrient (nitrogen). The result is a prolonged survival in quiescence until an improvement of the environmental conditions (nutrient availability) allows the rebuilding of the photosynthetic apparatus and the full recovery of cell functions.

Regulation of Phagotrophy by Prey, Low Nutrients, and Low Light in the Mixotrophic Haptophyte Isochrysis galbana

2021 ◽  
Author(s):  
Juan Manuel González-Olalla ◽  
Juan Manuel Medina-Sánchez ◽  
Alessandra Norici ◽  
Presentación Carrillo
Keyword(s):  
Isochrysis Galbana ◽  
Low Light

Effect of growth rate on the eicosapentaenoic acid and docosahexaenoic acid content of Isochrysis galbana in chemostat culture

1994 ◽  
Vol 41 (1) ◽  
pp. 23-27 ◽  
Author(s):  
E. Molina Grima ◽  
J. A. S�nchez P�rez ◽  
F. Garc�a Camacho ◽  
J. M. Fern�ndez Sevilla ◽  
F. G. Aci�n Fern�ndez
Keyword(s):  
Growth Rate ◽  
Docosahexaenoic Acid ◽  
Eicosapentaenoic Acid ◽  
Acid Content ◽  
Chemostat Culture ◽  
Isochrysis Galbana

Extracellular carbohydrate liberation in the flagellates Isochrysis galbana and Prymnesium parvum

1965 ◽  
Vol 45 (3) ◽  
pp. 755-772 ◽  
Author(s):  
A. F. H. Marker
Keyword(s):  
Organic Matter ◽  
Light Intensity ◽  
Nitrogen Starvation ◽  
Axenic Culture ◽  
Isochrysis Galbana ◽  
Prymnesium Parvum ◽  
Extracellular Production ◽  
Low Light ◽  
Passive Release ◽  
Dying Cells

The production of extracellular carbohydrate has been studied in Isochrysis galbana and Prymnesium parvum in axenic culture. Increased extracellular production of carbohydrate occurred at reduced and increased salinity, low light intensity and under conditions of nitrogen starvation in Isochrysis, and in some cases appeared to be associated with the sedimentation of the cells from stagnant culture. Extracellular carbohydrate production was found to be greatest during the early and later stages in growth and dropped to a minimum during the mid-growth phase. Experiments indicated that the cells were not being damaged during harvesting of the cultures. A close similarity was found between the monosaccharide components of the intra- and extracellular carbohydrate after acid hydrolysis; both contained glucose, galactose, arabinose, xylose and ribose. It is suggested that the production of most of the extracellular carbohydrate is due to the passive release of organic matter from dead or dying cells.

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