Fig. 5.

Biogas production from groundwater samples amended with (A) YPG medium and BES and (B) YPG medium incubated at temperatures of groundwater samples measured at the outflow of the well. Cumulative measurements in the gas phase of bottled cultures are shown as follows: H₂ (○); CH₄ (■); and CO₂ (△). Incubation temperatures are shown in parentheses. Although representative results of cultures performed in duplicate are shown, the other culture showed a similar potential for biogas production.