Figure 1.

¹³C-decoupled two-dimensional ¹H‒¹H J-resolved spectroscopy (2D-Jres-dc) (a,c,e,g) and ¹H‒¹³C heteronuclear single quantum coherence‒total correlation spectroscopy (HSQC‒TOCSY) (b,d,f,h) spectra for metabolites transformed from ¹³C₆–glucose by a natural aquatic bacterial community (final concentration added, 500 µM C) (Experiment 1). Signals were obtained after a 2-day incubation of a seawater sample collected from a coastal location. Spectra for the δ¹H (δ¹³C) ranged from 0.8 to 2.26 (10–45) (a,b); 1.8–4.3 (21–71) (c,d); 3.1–5.5 (52–105) (e,f); and 5.7–8.5 (83–155) ppm (g,h) are shown. Numbers indicate the corresponding metabolites listed in Table 1 (amino acids: red; dipeptides: orange; carboxylic acids: brown; nucleosides and nucleobases: green; carbohydrates: blue; amino alcohols: purple). Greek letters or numbers in parentheses for amino acids and nucleobases, respectively, denote the atom designation. In (a), an increased (×6) contour intensity magnitude was used for the δ¹H range 1.6–2.26 ppm relative to the rest of the field (0.8–1.6 ppm). For the detailed analytical settings, see Table S1.