Semi-quantification of H₂S production illustrated in Fig 2.

Bacteria were cultured in M9 minimal medium (M9 salts plus 2 mM MgSO₄, 0.1 mM CaCl₂, and 0.2% casein acid hydrolysate as sole carbon source) containing appropriate antibiotic and inducers. H₂S production during growth was monitored with lead acetate paper strips in anaerobic test tubes. Paper strips were scanned for quantification of H₂S yield, with reference to NaHS standard. The calibration curve for sulfide was Y = 3×10⁶ x—3955.4 (R² = 0.9993), for X representing the amount of sulfide (μmole) and Y representing the integrated density of gray values measured with ImageJ software. Significance was determined by t-test; p-value: ***, <0.001.

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