Figure 3.

Schematic examples illustrate that ¹³C-analysis can be utilized to determine the contributions of various biosynthetic pathways towards final product yield. (A) ¹³C analysis to study the carbon assimilation during syngas fermentation (¹³CO₂, ¹²CO and H₂). Analysis of metabolite labeling patterns can determine CO₂ and CO utilization for pyruvate production. The isotopomer data of pyruvate was used as a demonstration of ¹³C applications for product yield calculations. (B) Threonine and citramalate pathway for the synthesis of 1-butanol. The carbon rearrangement network shows the labeling of 1-butanol from the two biosynthesis pathways, when fed with 1-¹³C pyruvate and ¹³C bicarbonate.