As absolute incorporation of tracer 13C into P-PLFA was much
lower than into the other two pools, the DI aids in the observation
of the sugar positions' incorporation pattern into
P-PLFA (see Supplementary, Figure 1). Interestingly, on day 3, the incorporation
pattern of glucose positions into P-PLFA was different to that of
microbial biomass: we found a preferential incorporation of
glucose 13C-2 and the highest discrimination against glucose 13C-4.
On day 10, the difference in the relative incorporation of individual
positions was no longer significant.