Autotrophic: Synthesis of organic matter from external inorganic substances.
① Photoautotrophic: photosynthetic bacteria, cyanobacteria (using water as hydrogen donor), purple sulfur bacteria and green sulfur bacteria (using H2S as hydrogen donor and strictly anaerobic) 2H2S+CO2→ [CH2O]+H2O+2S.
② Photoenergy heterotrophy: Photosynthesis takes light as energy and organic matter (formic acid, acetic acid, butyric acid, methanol, isopropanol, pyruvic acid and lactic acid) as carbon source and hydrogen donor. Sunlight bacteria use pyruvate and lactic acid as the only carbon sources for photosynthetic growth.
③ chemoautotrophic: sulfur bacteria, iron bacteria, hydrogen bacteria, nitrifying bacteria and methanogenic bacteria (anaerobic autotrophic bacteria) CO2+4H2→CH4+2H2O.
④ Chemotactic heterotrophy: parasitic bacteria and saprophytic bacteria.
⑤ Aerobic bacteria: nitrifying bacteria, Corynebacterium glutamicum, Brevibacterium flavum, etc.
⑥ Anaerobic bacteria: lactic acid bacteria, tetanus bacillus, etc.
⑦ Intermediate type: Rhodosporium (photoautotrophic, chemoheterotrophic, anaerobic [facultative photoautotrophic]), Hydromonas (chemoautotrophic, chemoheterotrophic [facultative autotrophic]) and yeast (aerobic, anaerobic [facultative anaerobic]).
(8) Nitrogen-fixing bacteria: nitrogen-fixing microorganisms (rhizobia, etc.). ) and autotrophic nitrogen-fixing microorganisms (chromosphere nitrogen-fixing bacteria).