FIG. 6.

¹H NMR (300-MHz) spectra of ethanol extracts of H. elongata salt-sensitive mutant strains CHR62 (ectA::Tn1732) and CHR63 (ectC::Tn1732) and of CHR61 (wild-type strain) grown in M63 medium supplemented with 0.65 M NaCl. The arrows indicate the position of the hydroxyectoine resonance. Abbreviations: H, hydroxyectoine; E, ectoine. The biosynthetic pathway for ectoines from DA is also shown. The solid and dashed lines indicate established and proposed steps, respectively. The letter X represents an intermediate in hydroxyectoine biosynthesis that has not been identified so far.