Abstract
	Acidithiobacillus ferrooxidans oxidized elemental powdered sulfur to sulfuric acid in batch culture at aerobic conditions. The kinetics of bacterial growth and sulfur oxidation were evaluated from CO2 and O2 consumption rates, respectively. The culture achieved a maximum specific growth rate (?? of 0.043 h-1 (doubling time 16 hours). The exponential growth phase was followed by the lasting phase with a gradual decrease of the specific growth rate. The bacterial growth and sulfur oxidation stopped at pH 0.7. The H+ protons are considered as a main inhibitor of the bacterial growth and of the sulfur oxidizing activity.