File:Termite protists and bacteria symbionts.jpg

English: Parabasalia protist endosymbionts and associated bacteria in the termite hindgut. Wood microchips are ingested by phagocytosis, the cellulose digested to glucose and passed to the cytoplasm; undigested food vacuole contents are primarily lignin which is excreted; the glucose is fermented to acetate and lactate by glycolysis, and the excess passes into the lumen for the free bacteria; some ectosymbionts transform N2 into nitrogenous organic molecules (Norg), mostly amino acids; some nitrogen fixation also takes place inside by endosymbionts; H2 production from nitrogen fixation is used by methanogens releasing CH4; some ectosymbionts obtain NH3 from digestion of uric acid by lumen bacteria, to synthesise Norg; excess Norg from bacteria synthesis is passed to the protist and to the lumen for other organism and for the termite to absorb. Citation: S. Adl (2024). Organellar loss and gain of function. In: Protistology (Elsevier), Chapter 21.