Financial support: This work was part of a project financed by Ministry of Sciences, Technologies and Environment of Cuba.

Keywords: bacteria, bacterial growth, conductimetric titration, microorganisms, sulfur-containing gases.

Abbreviations: rpm: revolutions per minute.

A simple and economical minibioreactor-gas collector system for determination of hydrogen sulfide produced by a microorganism was designed. The detection of hydrogen sulfide was based on the reaction between the hydrogen sulfide in the gas stream from the culture, and a lead acetate solution 0.090 mol/L, contained in a tube gas collector; the conductimetric back titration of lead excess was made, and hydrogen sulfide was quantified indirectly, being the detection limit 0.5 µmol. The developed system was applied using Tsukamurella paurometabola DSM 20162 as a model, being the amount of hydrogen sulfide produced, 1.2 µmol in 24 hrs.