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Jeanpascal Berge - One of the best experts on this subject based on the ideXlab platform.

  • antibacterial activity of the marine diatom Skeletonema costatum against aquacultural pathogens
    Aquaculture, 1999
    Co-Authors: M Naviner, Jeanpascal Berge, P Durand, Le H Bris
    Abstract:

    Abstract The antibacterial activity of Skeletonema costatum (Grev.) Cleve against aquacultural bacteria was examined. The active compounds, partly purified from an organic phase, were tested against some pathogens of shellfish or fish. The growth of Listonella (=Vibrio) anguillarum and several species of the genus Vibrio appeared to be inhibited.

  • reassessment of lipid composition of the diatom Skeletonema costatum
    Phytochemistry, 1995
    Co-Authors: Jeanpascal Berge, Jean Paul Gouygou, Jean Paul Dubacq, Patrick Durand
    Abstract:

    In the present work, we questioned the natural or artifactual origin of the large amounts of free fatty acids recovered in lipids from the diatom Skeletonema costatum. Using rapid cell harvest and a very drastic method to extract the lipids, we demonstrated that these lipid patterns rich in free fatty acids were relevant to the degradation of complex lipids. A revised lipid composition of S. costatum is given which differs from those previously described by the absence of free fatty acids, while the proportion of polar lipids is substantially increased. Membrane lipids are mostly represented and storage lipids are less abundant, since we analysed the cells during their exponential growth phase. However, the fatty acid composition is in agreement with previous data. Polyunsaturated fatty acids (PUFA) consist essentially of 20: 5 to3, 16: 3 04 and 16: 4 to 1, while 16: 1 m7 is the main monounsaturated FA. This confirms that, with regard to its lipid composition, the diatom, S. costatum, provides a good diet for molluscs, particularly through its high proportion of eJ3 PUFA. Using this extraction procedure, sterols were found to be identical to previous results but a new compound, a 18:1 fatty alcohol, was detected. The consequences of this reassessement on the lipid compositions of diatoms so far published and their application to the lipid diet of mollusc larvae in aquaculture are discussed.

Jiangtao Wang - One of the best experts on this subject based on the ideXlab platform.

  • growth inhibition of the microalgae Skeletonema costatum under copper nanoparticles with microplastic exposure
    Marine Environmental Research, 2020
    Co-Authors: Weihong Zhao, Xiaohua Chen, Ting Zhao, Jiangtao Wang
    Abstract:

    Abstract In order to investigate the combined toxicities of copper nanoparticles (nano-Cu) with microplastic on microalgae Skeletonema costatum, growth inhibition tests were carried out. The toxic effects of copper nanoparticles and microplastic on the microalgae under singleness and coexistence conditions were investigated. Both copper nanoparticles and microplastic inhibited the growth of S. costatum. The growth inhibition ratio (IR) increased with the increasing of particle concentrations and incubation time. The toxicity of copper nanoparticles was reduced with the addition of microplastic. The concentrations of Cu2+ in the medium with or without addition of microplastic were determined. It was found that adsorption of Cu2+ on microplastic and aggregation between copper nanoparticles and microplastic are the main reasons for attenuation of toxicity of nano-Cu with adding microplastic. The adhesion and aggregate interactions between microalgae and nanomaterial were also approved by the observations through scanning electron microscopy.

  • Allelopathic interactions between Skeletonema costatum and Alexandrium minutum
    Chemistry and Ecology, 2017
    Co-Authors: Rui Wang, Jiangtao Wang
    Abstract:

    ABSTRACTPotential allelopathic interactions between Skeletonema costatum and Alexandrium minutum were investigated using mixed cultures and culture filtrate in nutrient-replete medium. A. minutum growth was inhibited when grown in S. costatum filtrate, with the inhibitory effect directly proportional to the percentage of filtrate added. This demonstrates that the release of allelopathic compounds caused the growth inhibition. In contrast, the filtrate of A. minutum exerted no allelopathic activity on S. costatum. An autoinhibitory compound (15(S)-HEPE) extracted and purified from S. costatum culture was added to cultures of both S. costatum and A. mintum. This substance could depress S. costatum growth, but showed no significant inhibitory activity on A. minutum. This documented a second type of allelochemical interaction, termed auto-allelopathy, caused by a different compound from the one or ones that affected A. minutum in the co-cultures with added crude filtrate. Further studies are needed to explore...

  • toxic effects of nano zno on marine microalgae Skeletonema costatum attention to the accumulation of intracellular zn
    Aquatic Toxicology, 2016
    Co-Authors: Cai Zhang, Jiangtao Wang, Xiaohua Chen
    Abstract:

    Abstract To explore toxic mechanisms of nano-ZnO on marine microalgae, algal growth inhibition test was carried out, and total Zn in the cell and total dissolved Zn in f/2 medium were determined. It was found that nano-ZnO was more toxic than bulk-ZnO on marine microalgae Skeletonema costatum. No matter under nano-ZnO or bulk-ZnO treatment, accumulation of intracellular Zn had a good linear correlation with growth inhibition ratio (IR). The total Zn content in the cell of microalgae was the dominant toxic mechanism of ZnO. Intracellular total Zn could be an indispensable parameter to indicate the toxic effects of nano-ZnO. Higher intracellular total Zn under nano-ZnO treatment than bulk-ZnO resulted in more toxicity of nano-ZnO on microalgae. Compared with Zn2+ released by nano-ZnO into medium, lipid peroxidation (MDA level) injury, aggregation of nano-ZnO and transmembrane process of nano-ZnO also contributed to toxicity of nano-ZnO on Skeletonema costatum. The accumulation of intracellular Zn provides a new insight into toxic mechanisms of nano-ZnO.

  • Effect of allelopathy on the competition and succession of Skeletonema costatum and Prorocentrum donghaiense
    Marine Biology Research, 2015
    Co-Authors: Yiwen Zhang, Jiangtao Wang, Hui Li
    Abstract:

    AbstractProrocentrum donghaiense and Skeletonema costatum are typical coexisting species found in the East China Sea. However, P. donghaiense blooms usually occur after S. costatum in the spring and summer season. The mechanisms of controlling this succession remain unclear; we propose that it might be allelopathy. Bi-algal cultures in seawater and S. costatum filtrate were used to examine the effect of allelopathy on the competition between S. costatum and P. donghaiense. The result of comparable experiments between axenic and non-axenic media indicated that the active bacteria were not the predominant factor affecting the competitive results, and non-autoclaved filtrates were then used in the bi-algal culture experiments. The results of bi-algal cultures showed that S. costatum was the dominant species in the seawater when nutrient concentrations and algae ratios in the cultures were similar to those in the field. In contrast, the evident succession between S. costatum and P. donghaiense in the S. costa...

Le H Bris - One of the best experts on this subject based on the ideXlab platform.

Mitchell L Sogin - One of the best experts on this subject based on the ideXlab platform.

Xiaohua Chen - One of the best experts on this subject based on the ideXlab platform.

  • growth inhibition of the microalgae Skeletonema costatum under copper nanoparticles with microplastic exposure
    Marine Environmental Research, 2020
    Co-Authors: Weihong Zhao, Xiaohua Chen, Ting Zhao, Jiangtao Wang
    Abstract:

    Abstract In order to investigate the combined toxicities of copper nanoparticles (nano-Cu) with microplastic on microalgae Skeletonema costatum, growth inhibition tests were carried out. The toxic effects of copper nanoparticles and microplastic on the microalgae under singleness and coexistence conditions were investigated. Both copper nanoparticles and microplastic inhibited the growth of S. costatum. The growth inhibition ratio (IR) increased with the increasing of particle concentrations and incubation time. The toxicity of copper nanoparticles was reduced with the addition of microplastic. The concentrations of Cu2+ in the medium with or without addition of microplastic were determined. It was found that adsorption of Cu2+ on microplastic and aggregation between copper nanoparticles and microplastic are the main reasons for attenuation of toxicity of nano-Cu with adding microplastic. The adhesion and aggregate interactions between microalgae and nanomaterial were also approved by the observations through scanning electron microscopy.

  • toxic effects of nano zno on marine microalgae Skeletonema costatum attention to the accumulation of intracellular zn
    Aquatic Toxicology, 2016
    Co-Authors: Cai Zhang, Jiangtao Wang, Xiaohua Chen
    Abstract:

    Abstract To explore toxic mechanisms of nano-ZnO on marine microalgae, algal growth inhibition test was carried out, and total Zn in the cell and total dissolved Zn in f/2 medium were determined. It was found that nano-ZnO was more toxic than bulk-ZnO on marine microalgae Skeletonema costatum. No matter under nano-ZnO or bulk-ZnO treatment, accumulation of intracellular Zn had a good linear correlation with growth inhibition ratio (IR). The total Zn content in the cell of microalgae was the dominant toxic mechanism of ZnO. Intracellular total Zn could be an indispensable parameter to indicate the toxic effects of nano-ZnO. Higher intracellular total Zn under nano-ZnO treatment than bulk-ZnO resulted in more toxicity of nano-ZnO on microalgae. Compared with Zn2+ released by nano-ZnO into medium, lipid peroxidation (MDA level) injury, aggregation of nano-ZnO and transmembrane process of nano-ZnO also contributed to toxicity of nano-ZnO on Skeletonema costatum. The accumulation of intracellular Zn provides a new insight into toxic mechanisms of nano-ZnO.