FIG 1.

Production of H₂ and CO₂ in different saccharide treatments. Triplicate anoxic microcosms with gut content (A to D) or soil (E to H) were supplemented with the following saccharides: arabinose (●), fucose (⬥), galactose (◇), glucose (○), maltose (▽), mannose (△), rhamnose (▲), and xylose (▼). The gray squares represent the unsupplemented controls. Incubation was at 15°C in the dark. Additional information on the substrate/product profiles of the treatments is shown in Table 1. Error bars indicate standard deviations. Statistical P values are shown in Table S1 in the supplemental material.