Publications by authors named "M Crouvoisier"
Turbulence is one of the least investigated environmental factors impacting the ecophysiology of phytoplankton, both at the community and individual species level. Here, we investigated, for the first time, the effect of a turbulence gradient (Reynolds number, from Reλ = 0 to Reλ = 360) on two species of the marine diatom Pseudo-nitzschia and their associated bacterial communities under laboratory conditions. Cell abundance, domoic acid (DA) production, chain formation, and Chl a content of P.
View Article and Find Full Text PDFAlong with their important diversity, coastal ecosystems receive various amounts of nutrients, principally arising from the continent and from the related human activities (mainly industrial and agricultural activities). During the 20th century, nutrients loads have increased following the increase of both the global population and need of services. Alongside, climate change including temperature increase or atmospheric circulation change has occurred.
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- Understanding how phytoplankton adapt their photosynthesis to different underwater light conditions is crucial for grasping primary production in aquatic ecosystems.
- A study collected phytoplankton samples across the English Channel in spring and analyzed their photosynthetic properties using a specialized chlorophyll fluorometer.
- The findings showed that these phytoplankton communities were better protected from blue light but not from other colors, indicating that their ability to adapt to varying light quality impacts their ecological roles in coastal environments.
The MraY transferase catalyzes the first membrane step of bacterial cell wall peptidoglycan biosynthesis, namely the transfer of the N-acetylmuramoyl-pentapeptide moiety of the cytoplasmic precursor UDP-MurNAc-pentapeptide to the membrane transporter undecaprenyl phosphate (C55P), yielding C55-PP-MurNAc-pentapeptide (lipid I). A paralogue of MraY, WecA, catalyzes the transfer of the phospho-GlcNAc moiety of UDP-N-acetylglucosamine onto the same lipid carrier, leading to the formation of C55-PP-GlcNAc that is essential for the synthesis of various bacterial cell envelope components. These two enzymes are members of the polyprenyl-phosphate N-acetylhexosamine 1-phosphate transferase superfamily, which are essential for bacterial envelope biogenesis.
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- Lipids II from some Gram-positive bacteria were created using radioactive l-lysine-containing UDP-MurNAc-pentapeptide.
- Specific lateral chains unique to bacteria like Enterococcus faecalis, Enterococcus faecium, and Staphylococcus aureus were added through chemical synthesis techniques.
- The resulting lipids were hydrolyzed by colicin M from Escherichia coli at similar rates as those found in Gram-negative bacteria, suggesting potential for colicin M as a broad-spectrum antibacterial agent.