1 Common bacteria: Escherichia coli (commonly used in culture and experiment), Staphylococcus, Vibrio cholerae, Spirillum, Acetobacter (producing acetic acid through aerobic respiration), Lactic acid bacteria (performing anaerobic respiration, making pickles, making yogurt, etc. These are prokaryotes and should be distinguished from eukaryotes such as fungi and molds.

Photosynthetic bacteria can carry out photosynthesis and nitrifying bacteria can carry out nitrification. They are all autotrophs (ordinary bacteria are heterotrophic).

Nitrogen-fixing bacteria (rhizobia and chromosphere nitrogen-fixing bacteria) can fix nitrogen and play an important role in nitrogen cycle.