3-Hydroxypropionate Pathway is a CO2 assimilatory pathway observed in bacteria. Inorganic CO2 is fixed by acetyl-CoA and propionyl-CoA carboxylases thus forming malyl-CoA and glyoxylate. Malyl-CoA is further split into acetyl-CoA (to replenish this cycle). Researchers have demonstrated that this pathway was found only in Chloroflexus, a nonsulfur photosynthetic bacterium, however recent studies show that 3-Hydroxypropionate pathway is found in several chemotrophic archaea.