Effect of the Availability of the Source of Nitrogen and Phosphorus in the Bio-Oxidation of H₂S by Sulfolobus metallicus

The effect of nitrogen and phosphorus availability on the growth of Sulfolobus metallicus was analyzed. This archaeon was subjected to a series of nitrogen and phosphorus limitation conditions to determine their effects on growth. The results indicate that Sulfolobus metallicus showed a relationship between one of the intermediate oxidation products (tetrathionate) and cell concentration during the exponential growth phase in the absence of nitrogen. Furthermore, significant differences were found in the specific growth rates under different scenarios with ammonia and phosphorus limitation, with values of 0.048 h⁻¹ in the ammonia limitation case. The biomass substrate yield obtained was 0.107 g_cel·g S⁻¹. Meanwhile, in the absence of phosphorus, the specific growth rate was 0.017 h⁻¹, and the substrate to biomass yield was 0.072 g_cel·g S⁻¹. The results indicate that the ability of Sulfolobus metallicus to bio-oxidize H₂S depends on the availability of such nutrients (nitrogen and phosphorus), which affect cellular growth and the types of products generated. This, in turn, influences the oxidation process of various sulfur compounds, resulting in changes in the predominant products formed and the final oxidation of sulfate ions.