6 - Aerobic Respiration—Chemolithotrophic Bacteria

Abstract

This chapter explains aerobic respiration of chemolithotrophic bacteria. Aerobic or oxidative respiration involves a considerably greater number of processes than fermentation or anaerobic respiration. It is the enzymatic oxidation of fuel molecules by molecular oxygen. In microbiology, there is a complex group of organisms that are not able to use the tricarboxylic acid cycle but use molecular oxygen as their final electron acceptor. These microorganisms are the chemolithotrophic bacteria, which are mainly autotrophs and derive their energy by oxidizing inorganic compounds. They incorporate CO2 into the Calvin cycle for cellular biosynthesis. There are only a few bacterial groups that are able to oxidize an inorganic compound for the production of energy: (1) the nitroso group of genera; (2) the nitro group of genera; (3) the genus Hydrogenomonas or hydrogen bacteria, which oxidize hydrogen; (4) the ferrous iron-oxidizing bacteria; and (5) the sulfur-oxidizing bacteria.