Figure 3: Isotopic evidence for fungus-derived CH4 formation.

Stable carbon isotope values of CH4 (a,b), CH4 mixing ratios (c,d) and stable carbon isotope signature of CO2 (e,f) in the headspace during the incubation of L. sulphureus and P. sapidus on 13C-labelled glucose. The control jars (n=3) contained sterile medium only. Error bars represent s.d. of mean.