Nutritional types of microorganisms PhototrophS: use light as energy source Chemotrophs: obtain energy from the OXidation of chemical compounds Lithotrophs: use reduced inorganic substances as their electron source Organotrophs: exteact electrons from organic compoundsNutritional types of microorganisms • Phototrophs: use light as energy source. • Chemotrophs: obtain energy from the oxidation of chemical compounds. • Lithotrophs: use reduced inorganic substances as their electron source. • Organotrophs: exteact electrons from organic compounds