Chemoautotroph Bacteria Electron Electron Products donor acceptor alcaligens and H O H2O Pseudomonas sp Nitrobacter NO2 O NO3.H2O Nitrosomonas NH4 NO2.H2O Desulfovibrio H2 SO42- H2O. H2S Thiobacillus denitrificans So. H2S NO3 SO42N2 Thiobacillus ferrooxidans Fe O Fe3+ H2o Nitrifying bacteria 2NH4++302 2 NO2-+2 H20+4H++132 KcalChemoautotroph: Nitrifying bacteria 2 NH4 + + 3 O2 2 NO2- + 2 H2O + 4 H+ + 132 Kcal Bacteria Electron donor Electron acceptor Products Alcaligens and Pseudomonas sp. H2 O2 H2O Nitrobacter NO2 - O2 NO3 - , H2O Nitrosomonas NH4 + O2 NO2 - , H2O Desulfovibrio H2 SO4 2- H2O. H2S Thiobacillus denitrificans S0 . H2S NO3 - SO4 2- , N2 Thiobacillus ferrooxidans Fe 2+ O2 Fe 3+ , H2O