Iron sulfide minerals crystallization in the presence of sulfur and clay minerals in media containing sulfate-reducing bacteria

This study aimed to synthesize Fe-sulfides in cultures of sulfate-reducing bacteria consortium under laboratory conditions with the time, Fe:S ratio, and addition or lack of oxidizing agent and/or clay mineral matrix. Here we sought to determine the role that SRM plays in iron sulfide mineral formation using a series of lab-based incubations that included live cultures and abiotic treatments. In the present contribution, the sulfate-reducing microorganisms were cultured with sulfur to investigate the effect of the oxidant agent on the nature of iron sulfides formed. In addition, the effect of the presence of a crystallization matrix, in the form of clay minerals, on the process of formation or morphology of crystallizing iron sulfides was investigated.These results allow an understanding of the evolution and mechanisms of pyrite formation in sulfate-reducing consortia cultures and discuss implications for natural environments.