FIG 1.

Response of NO₂⁻ production by N. viennensis (A) and N. gargensis (B) to different aqueous concentrations of octyne (Oct). Cell suspensions were added to their respective media pre-equilibrated with Oct in the presence of 1 mM NH₄⁺. Bottles were incubated at 42 or 46°C for N. viennensis and N. gargensis, respectively, and the accumulation of NO₂⁻ was monitored. Experiments were repeated three times (in triplicate) with similar results. Error bars represent the standard deviations of three replicate bottles of each treatment.