Dear Stanley: Differences Between Atmospheres for Microorganism Growth

Dear Stanley,

I want to make sure I’m using the right atmosphere to get good growth of my microorganisms. Can you explain the differences between aerobic, anaerobic, microaerophilic, and capnophilic atmospheres for microorganism growth?

Beth from Salt Lake City, UT

Dear Beth,

I would be glad to explain the differences!


Let me start with the most common atmosphere, aerobic. An aerobic atmosphere is composed primarily of oxygen (21%) and a small amount of carbon dioxide (0.03%). Because the atmosphere is oxygen-rich, it’s an ideal environment for obligate aerobes and facultative anaerobes.

An example of an obligate aerobe: Pseudomonas aeruginosa

More tips on growth success with aerobes: Methods for Growth Success: Aerobic Microorganisms


An anaerobic atmosphere either contains zero or very little oxygen. This atmosphere is best for growing facultative anaerobes and obligate anaerobes. Providing an anaerobic atmosphere is especially important for obligate anaerobes who can only tolerate oxygen levels of <0.5% to 0.8%.

An example of an anaerobe: Clostridium difficile

More tips on growth success with anaerobes: Methods for Growth Success: Obligate Anaerobes


A microaerophilic atmosphere is ideal for a microorganism that can grow under reduced oxygen and increased carbon dioxide levels. The composition of this atmosphere is between 8-10% carbon dioxide and 5-10% oxygen. A microaerophilic atmosphere is most easily obtained using specially designed generating systems to create and monitor the desired levels of oxygen and carbon dioxide. These systems typically include jars or pouches and sachets.

The most common microaerophile: Campylobacter sp

Tips on growth success with microaerophiles: Methods for Growth Success: Microaerophiles

Capnophilic (Carbon Dioxide Enriched)

A capnophilic atmosphere, or carbon dioxide enriched, has an elevated level of carbon dioxide to facilitate the growth of capnophilic bacteria. This atmosphere is typically between 5-10% carbon dioxide and approximately 15% oxygen.  A candle jar may be appropriate for some microorganisms that require a higher level of carbon dioxide in the atmosphere to grow. Candle jars usually provide about 3-5% carbon dioxide and 8-10% oxygen, and can also be used for microaerophiles that don’t require an elevated carbon dioxide level for growth.

An example of a capnophilic microorganism: Haemophilus influenzae

Tips on growth success with capnophiles: Methods for Growth Success: Carbon Dioxide Dependent Microorganisms

For detailed descriptions of growth methods for all Microbiologics strains, check out our Growth Requirements document. Our Technical Support team is also here to help if you need guidance determining the best atmosphere for your microorganisms.


Stanley Staphylococcus


Stanley Staphylococcus is a Master Micro-Technologist at Microbiologics, where he is responsible for helping customers understand why microorganisms behave the way they do. You could say he’s somewhat of a psychologist. Microbiologics has been lucky to have Stanley, a graduate of Gram-Positive Cocci University, as a member of their renowned Technical Support Team for over 20 years. Stanley says his favorite type of people are microbiologists and he enjoys traveling far and wide to meet them. Amazingly, Stanley has been on every continent – even Antarctica!

How to submit inquiries: There are two ways to get Stanley’s help. You can email your questions to or you can simply submit an inquiry from our Dear Stanley page. For urgent issues, please contact our Technical Support Team at or 1.320.229.7045.



Tankshewar. “Oxygen Requirements for Pathogenic Bacteria.” Microbe Online, 10 June 2016,

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