FIG 1.

Use of molecular hydrogen as a sole electron donor by Prolixibacter sp. MIC1-1. Experiments were performed under three different initial concentrations of molecular hydrogen (8.8, 48.5, and 94.7 μmol/20 ml) with nitrate as the electron acceptor, and the concentration of residual molecular hydrogen in the headspace (20 ml) of each bottle was determined at the end of the experiment. Solid bars, Prolixibacter sp. MIC1-1 cultures; open bars, aseptic control. The data points and error bars represent means and standard deviations, respectively (n = 3).