Growth Characteristics of Acidithiobacillus thiooxidans in Different Sulfur Concentrations

The growth characteristics of sulfur-oxidizing bacteria, Acidithiobacillus thiooxidans AZ11, MET, and TAS were investigated in mineral salt media supplemented with elemental sulfur of 150 g . The sulfur oxidation rates of A. thiooxidans. MET and TAS increased highly with increasing sulfur concentration up to 10 g L, but the rates increased slowly in sulfur concentration over 10 g L. A. thiooxidans AZ11 showed the parallel increase of sulfur oxidation rate until sulfur concentration increased up to 40 g L. The maximum sulfur oxidation rates (V) of AZl1, MET and TAS were 1.88, 1.38 and 0.43 g S L d, respectively. The maximum specific growth rates () of AZ11, MET, and TAS were 0.33 d, 0.30 d and 0.45 d, respectively. Although MET and TAS couldn't grow at sulfate concentration of 40 g L, AZ11 could grow in the presence of 58 g L sulfate, the final oxidation product of elemental sulfur.