Realizing the potential of nitro-compounds to reduce ruminant enteric methane emissions, my objective was to research and obtain various natural sources of nitro-compounds that have the potential to be developed into ruminant livestock feed supplements. I researched several plant, bacterial, and fungal species as potential sources of the nitro-compound 3-nitro-1-propionic acid (3-NPA). I will present possible sources and biochemical pathways that will be useful targets to explore the synthesis of 3-NPA through further genetic manipulations.