Analysis and modeling of the photoautotrophic activity of Allochromatium vinosum

This work focuses on the photoautotrophic metabolism of Anoxygenic phototrophic sulfur bacteria (APSB), using a pure strain Allochromatium vinosum, to explore their potential for mineral carbon capture and sulfide treatment. Batch kinetics of this strain were carried out in sacrificial vials exposed to IR light (35 W.m^-2), with inorganic carbon and sulfides as substrates. A maximum specific growth rate of 0.092 h^-1 was found. The data obtained enabled the build and calibration of a mechanistic model which represents the evolution of sulfur substrates, nutrients and biomass. The stoichiometric and kinetic parameters were either found in literature, calculated or estimated with experiments. The model successfully describes the complexity of intermediary reactions of sulfur compounds, considering thiosulfates and "elemental sulfur" globules. Finally, it fits the evolution of substrates and biomass from different sets of data obtained in this study and from literature, with both pure and mixed culture of APSB.