Biological desulfurization has been studied during the last decades as a good option to treat sulfide rich streams as those generated for example from biogas desulfurization, anaerobic digestion of sulfate-rich wastewater or wastewater from sewer systems. These streams cause negative environmental impacts and it is necessary to implement efficient removal methods. Partial oxidation of sulfide, in microaerated reactors with suspended sulfide oxidizing bacteria (SOB) is a good alternative to remove sulfide. Partial oxidation allows recovering sulfide as elemental sulfur, which is a value added product; SOB are suitable for the low nutritional requirement, low oxygen demand (as sulfur is the end product), high sulfide affinity and removal, among other advantages. In this work, the biological sulfide oxidation process was studied to find the optimal operational conditions for sulfur recovery.