Desulfovibrio is a bacterium that breaks down organic matter which it must have and uses sulfate not oxygen as an electron acceptor. As a result, it produces hydrogen sulfide (H,S), accounting for the 'rotten egg'smell of swamp muck Oxygen is a deadly poison to Desulfovibrio. We would call Desulfovibrio a(n) (a) facultatively anaerobic chemoautotroph. (b) obligately anaerobic chemoheterotroph. (c) facultatively aerobic chemoheterotroph. (d) obligately anaerobic chemoautotropbh.