Toxicity of surfactants to green microalgae Pseudokirchneriella subcapitata and Scenedesmus subspicatus and to marine diatoms Phaeodactylum tricornutum and Skeletonema costatum

Chemosphere ◽  
2005 ◽  
Vol 61 (8) ◽  
pp. 1061-1068 ◽  
Author(s):  
Želimira Pavlić ◽  
Željka Vidaković-Cifrek ◽  
Dinko Puntarić
1985 ◽  
Vol 42 (7) ◽  
pp. 1272-1277 ◽  
Author(s):  
N. J. Antia ◽  
P. J. Harrison ◽  
D. S. Sullivan ◽  
T. Bisalputra

Diflubenzuron (Dimilin) was tested, in the concentration range 0.1–5000 μg∙L−1, for possible injurious effects on the growth and photosynthesis of three chitin-producing (Thalassiosira weissflogii, T. norden-skioldii, Cyclotella cryptica) and one nonchitinaceous (Skeletonema costatum) diatoms. For comparison, the effects of the pesticide were also examined on adult survival and juvenile development of the harpacticoid copepod Tigriopus californicus. While the development of the copepod was hindered at concentrations of the order of 1–10 μg∙L−1, the diatoms were barely affected by Dimilin even at the highest concentration tested (5 mg∙L−1). We conclude that Dimilin acts specifically on insects and crustaceans as a larvicide by interfering with chitin deposition into cuticles during juvenile development through ecdysis. The lack of effect from Dimilin on the chitin-producing diatoms has suggested that the insecticide may not inhibit chitin biosynthesis per se as was previously believed, but that it presumably deregulates one or more of the larval postsynthetic processes responsible for chitin integration into cuticles.


1984 ◽  
Vol 41 (3) ◽  
pp. 540-544 ◽  
Author(s):  
J. S. Parslow ◽  
P. J. Harrison ◽  
P. A. Thompson

Our new technique allows the decline in ambient ammonium concentration to be followed continuously during phytoplankton uptake experiments. A self-cleaning, in-line filter permits the continuous separation of cells from the medium for nutrient determination by an autoanalyzer. The technique works well with laboratory cultures of the marine diatoms Thalassiosira pseudonana and Skeletonema costatum. Changes in uptake rate on time scales of 1 min or longer can be resolved, the resolution being limited by the response characteristics of the autoanalyzer.


2019 ◽  
Vol 25 (4) ◽  
pp. 318-326 ◽  
Author(s):  
Danielli Matias de Macedo Dantas ◽  
Carlos Yure Barbosa de Oliveira ◽  
Romero Marcos Pedrosa Brandão Costa ◽  
Maria das Graças Carneiro-da-Cunha ◽  
Alfredo Olivera Gálvez ◽  
...  

Microalgae are considered one of the most promising raw materials for the development of high value products for pharmaceuticals, nutraceuticals, and cosmetic industries, as well as being potential sources of protein, vitamins, and minerals for human consumption. Hence, the present research focuses extraction of antioxidant and antimicrobial compounds from Scenedesmus subspicatus using solvents of different polarities. Different solvents such as ethanol, methanol, butanol, acetone, dimethyl sulfoxide, and water were used to extract compounds from the green microalgae S. subspicatus and then they were examined for phytochemical screening, antioxidant activity, and antimicrobial properties. In vitro free radical quenching and total antioxidant activity of extracts were investigated with 1,1-diphenyl-2-picryl hydrazyl and compared with catequin and gallic acid as positive controls. The antimicrobial activity was evaluated in gram-negative and gram-positive bacteria. Aqueous extracts and dimethyl sulfoxide presented better performance in phytochemical analysis. This result showed consistency in the sequential tests. The antioxidant activity was also better using the two solvents cited above. The extracts acetone, water, and dimethyl sulfoxide showed ability to inhibit the growth of Bacillus subtilis. However, only dimethyl sulfoxide inhibited the growth of Klebsiella pneumoniae and Escherichia coli. Use of the aqueous extract, proven its effectiveness, is an economic protocol and avoids the use of toxic substances.


1966 ◽  
Vol 23 (3) ◽  
pp. 357-364 ◽  
Author(s):  
R. G. Ackman ◽  
C. S. Tocher ◽  
J. McLachlan

Dimethyl-β-propiothetin has been reported from several species of freshwater and marine multicellular algae. Cultures of 14 species of unicellular marine algae were treated with cold aqueous alkali. Dimethyl sulphide was liberated from Syracosphaera carterae, Skeletonema costatum, Amphidinium carteri, Phaeodactylum tricornutum, Tetraselmis sp. and Cyclotella cryptica, and is assumed to arise from dimethyl-β-propiothetin. The amounts of alkali-labile material varied, on a wet weight basis, from 0.07 to 2.9% (as thetin salt) in different organisms. The presence of the thetin in S. carterae was confirmed by other means. The thetin, and particularly its degradation products, acrylic acid and dimethyl sulphide, may influence actual fishing operations and also affect the quality of fishery products. The metabolic and ecological significance of these materials are reviewed and discussed.


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