The a(alpha)Proteobacteria 。Chemoautotrophic: Oxidize nitrogen for energy 。FiⅸC02 ·Nitrobacter.NH3+→NO2 ·Nitrosomonas.NO2-→NO3 • Chemoautotrophic: • Oxidize nitrogen for energy • Fix CO2 • Nitrobacter. NH3 + → NO2 – • Nitrosomonas. NO2 – → NO3 – The  (alpha) Proteobacteria