“Aerobic bacteria are those that can survive or grow in the presence of oxygen”

Examples:

Bacillus, Nocardia, Pseudomonas.

Classification of aerobic bacteria:

There are three types of aerobic bacteria.

Obligate aerobes:

These bacteria are strictly survived in the presence of oxygen. These bacteria can’t live in the absence of oxygen. They immediately die if there is less than 20% oxygen in the environment

Facultative aerobes:

These bacteria can live either in the presence or in the absence of oxygen. These bacteria have anaerobic methods for energy production as well. They can ferment or produce energy for their metabolism.

Microaerophilic:

These bacteria can live in a small amount of oxygen. These bacteria can tolerate a high percentage of oxygen but love to live in a small amount of oxygen. They grow in 5% of oxygen level.

Aerobiosis:

Aerobic bacteria have catalase and superoxide dismutase enzyme. When oxygen accepts the free electrons from the electron transport chain, oxide and superoxide radicals are formed. These radicals are lethal for the growth of bacteria. But, aerobic bacteria have catalase and superoxide dismutase enzymes. These enzyme break oxide and superoxide radicals. When these radicals are broken down, the bacteria are free to grow and survive.

Source of energy:

These bacteria utilize glucose for energy. They undergo glycolysis that produces energy and pyruvic acid. Then, pyruvate form acetyl CoA that enters in Krebs cycle. This process produces an average of 38 ATP and CO₂.

Habitat:

These bacteria are present in almost every environment. They are present in the soil, water, human microbial flora. These bacteria can be isolated from the air.

How to culture these bacteria?

These bacteria can be grown on simple agar and selective agar. But it is mandatory to supply them with a good amount of oxygen so that they grow easily.