13.15 Fermentations: Energetic and redox consideration 13.16 Fermentative Diversity 13.17 Fermentations lacking substrate level phosphorylation 13.18 Anaerobic respiration: : General Principles 13.19 Nitrate reduction and Denitrification硝酸还原与反硝化 13.20 Sulfate Reduction 硫还原 13.21 Methanogenesis 产甲烷过程 13.22 Other Electron Acceptors