FIG 1 .

Glucose-derived ¹³C was incorporated into pyruvate, lactate, acetate, alanine, valine, serine, glycine, leucine, and isoleucine in R. mucilaginosa under both anaerobic and ambient-oxygen conditions. M+2, M+3, M+4, and M+5 indicate compounds that contained 2, 3, 4, and 5 ¹³C atoms, respectively. Isotope enrichment means an abundance of labeled ion/unlabeled ion (corrected for natural abundance). Isotope enrichment was greater at 24 h than at 8 h or 4 h. For pyruvate, alanine, valine, and acetate, greater isotope enrichment was observed under anaerobic conditions at 24 h. For lactate, glycine, serine, and isoleucine, greater isotope enrichment was observed under ambient-oxygen conditions at 24 h. The incorporation of glucose-derived ¹³C into leucine biosynthesis was not affected by oxygen conditions. Dashed lines and solid lines indicate multiple steps and one metabolic step(s) needed to obtain the metabolite, respectively. Error bars, means ± standard deviations (SD) (n = 3 bacterial cultures per group); TCA, citric acid cycle; PPP, pentose phosphate pathway.