FIG. 2.

MeBr oxidation by N. europaea in the presence of soil under water-saturated (5 ml) (a) and unsaturated (3 ml) (b) conditions. Cells (3 × 10⁸) of N. europaea were incubated with the equivalent of 11 g of oven-dried soil, 0.25 mM MeBr, and 10 mM NH₄⁺. □, minus soil; ⧫, plus soil; ○, minus soil and plus 1% acetylene; ▴, plus soil and 1% acetylene. Error bars represent the standard deviations of the means of three analytical replicates.