Bacteria are classified by their nutritional/energy strategy into heterotrophs, which import preformed organic substrates and feed them into central metabolic pathways (glycolysis, the TCA cycle, the pentose phosphate pathway) to generate energy and precursor metabolites; chemoautotrophs, which derive energy from inorganic ion electron flow and synthesize precursor metabolites de novo from carbon dioxide; and photoautotrophs, which use light to generate energy while similarly synthesizing precursors from carbon dioxide. Bacteria are further classified by oxygen requirement into strict aerobes, strict (obligate) anaerobes, facultative anaerobes, aerotolerant ("indifferent") anaerobes, and microaerophiles, reflecting differing physiological relationships to molecular oxygen. This belongs to microbiology, specifically bacterial physiology and metabolic/respiratory classification.
Bacteria are classified by their nutritional/energy strategy into heterotrophs, which import preformed organic substrates and feed them into central metabolic pathways (glycolysis, the TCA cycle, the…