Modern, Aerobic Bacteria

Aerobic bacteria prosper in the modern world. Raven and Curtis’ state that a single gram of soil may contain 2.5 billion bacteria, 400,000 fungi, and 50,000 algae. The total weight (worldwide) of these organisms is greater than the combined weight of all animal organisms, and most of the respiration that takes place in the world is due to bacteria and fungi.

Bacteria are abundant in sewage, stagnant water, and the bodies of living and dead organisms. Some bacteria require oxygen, while other bacteria require that oxygen be absent. Many, however, can grow in either type of situation.