FIG 3.

Immediate overexpression of sRNA-29 causes slower growth resulting from nitrite accumulation when grown on nitrate (A) or from slower nitrite consumption when grown on nitrite (B) due to reduced nirS expression. P. denitrificans plus empty pLMB509 vector (solid line) or sRNA-29 (dashed line) was grown under denitrifying conditions (with 20 mM nitrate [A] or with 3 mM nitrite [B] as the electron acceptor) with 10 mM taurine added to induce sRNA-29 overexpression at time zero (indicated with an arrow). OD₆₀₀ and nitrite levels were measured. Error bars represent the SD of results of comparisons between triplicate experiments, and where not visible, the bars are smaller than the symbols. (C) Soluble protein was extracted from both cultures at 24 h and subjected to SDS-PAGE and subsequent heme staining. P. den, P. denitrificans.