A bacterial additives treatment experiment was conducted to assess the microbial and biochemical changes in stored swine manure. Nitrate salt was added to a slurry of swine waste collected from a waste storage pit to identify the effects of varying levels of nitrate upon the microbial community and the resulting metabolic changes. This research was an attempt to reduce the formation of odorous sulfur-containing compounds and to increase the formation of odorless nitrogen gas by manipulating the metabolic pathways in anaerobic decomposition of the organic matter within manure. Sulfide production from swine wastewater was reduced approximately 45 percent with the addition of 1500 mg/l or more of nitrate to the wastewater.