Effect of nikkomycin on chitin spine formation in the diatomThalassiosira fluviatilis, and observations on its peptide uptake

The nucleoside antibiotic nikkomycin inhibited the formation of β-chitin spines by the diatom Thalassiosira fluviatilis, and slowed its growth rate, at a minimum inhibitory concentration of 4 µM. The resulting chitin-free cells sedimented much more rapidly in the cultures than did control cells. The uptake of nikkomycin was not antagonised by the dipeptides Gly-Val, Met-Met or Phe-Leu. Of Six dipeptides tested, Met-Met, Phe-Leu and Tyr-Gly were taken up by the diatoms, but Gly-Gly, Gly-Val and Ala-Ala were not.