Difference Between Thermophilic and Mesophilic Bacteria

The main difference between thermophilic and mesophilic bacteria is that the thermophilic bacteria live and thrive at relatively high temperatures whereas the mesophilic bacteria live and thrive in moderate temperatures. This means thermophilic bacteria live at 45-122 °C while mesophilic bacteria live at 20-45 °C. 

Thermophilic and mesophilic bacteria are two types of bacteria classified based on their optimal growth temperature. 

Key Areas Covered 

1. What are Thermophilic Bacteria
     – Definition, Temperature Range, Importance
2. What are Mesophilic Bacteria
     – Definition, Temperature Range, Importance
3. What are the Similarities Between Thermophilic and Mesophilic Bacteria
     – Outline of Common Features
4. What is the Difference Between Thermophilic and Mesophilic Bacteria
     – Comparison of Key Differences

Key Terms 

Mesophilic Bacteria, Optimal Growth Temperature, Thermophilic Bacteria

What are Thermophilic Bacteria 

Thermophilic bacteria grow at relatively high temperatures, which is 45-122 °C. They live in a variety of marine and terrestrial habitats. Some habitats of thermophilic bacteria are hot springs like those in Yellowstone National Park, deep-sea hydrothermal vents, and decaying plant matter such as peat bogs and compost. They have several biochemical and molecular strategies to withstand the deleterious effects of the high temperatures. Thermophilic bacteria have a variety of applications such as the production of heat-stable DNA polymerases used in PCR.  

Figure 1: A Thermal Spring at the Yellowstone National Park

What are Mesophilic Bacteria 

Mesophilic bacteria are the organisms that grow at moderate temperatures, which is 20-45 °C. The optimal growth temperature of mesophilic bacteria is 37 °C. Hence, bacteria in the human microbiome, as well as human pathogenic bacteria, are mesophiles. Some examples of mesophilic bacteria are Listeria monocytogenes, Streptococcus pyrogenes, Staphylococcus aureus, etc. 

Figure 2: Staphylococcus aureus

Mesophilic bacteria are used in the production of cheese, yoghurt, beer, and wine.  

Similarities Between Thermophilic and Mesophilic Bacteria 

• Thermophilic and mesophilic bacteria are two types of bacteria that grow in different optimal temperature conditions. 
• Both types of bacteria have unique benefits. 

Difference Between Thermophilic and Mesophilic Bacteria 

Definition 

The thermophilic bacteria refer to a type of extremophiles that thrives at relatively high temperatures while the mesophilic bacteria refer to a bacteria that grow best in moderate temperatures. 

Growth Temperature 

Thermophilic bacteria live at 45-122 °C while mesophilic bacteria live at 20-45 °C. 

Optimum Temperature 

The optimum temperature of the thermophilic bacteria is 50 °C while the optimum temperature of the mesophilic bacteria is 37 °C.  

Enzymes 

Thermophilic bacteria have enzymes that are functional at high temperatures while mesophilic bacteria do not have enzymes that are functional at high temperatures. 

Pathogens 

The thermophiles are not pathogens as they cannot grow at body temperatures while mesophilic bacteria can be pathogens. 

Applications 

Thermophilic bacteria produce heat-stable DNA polymerases used in PCR while mesophilic bacteria are used in the production of cheese, yogurt, beer, and wine. 

Examples 

Some thermophilic bacteria are Thermus aquaticus, Thermococcus litoralis, Calothrix, Synechococcus, etc. while some mesophilic bacteria are Listeria monocytogenes, Streptococcus pyrogenes, Staphylococcus auresu, etc. 

Conclusion 

Thermophilic bacteria are the bacteria that can grow at high temperatures such as 45-122 °C while mesophilic bacteria grow at moderate temperatures such as 20-45 °C. The thermophilic bacteria produce heat-stable DNA polymerases used in PCR while the mesophilic bacteria are used in the production of cheese, yogurt, and beer. Also, mesophilic bacteria can be pathogenic in humans. The main difference between thermophilic and mesophilic bacteria is the temperature range and the importance. 

Reference: 

1. “Temperature and Microbial Growth.” Lumen | Boundless Microbiology, Available Here
2. “Mesophile.” Biology Online Dictionary, Available Here
3. Li, Fu-Li. “Thermophilic Microorganisms.” Acinetobacter Molecular Biology,CaisterAcademic Press, Available Here

Image Courtesy:

1. “Thermal-Spring-Park-Yellowstone-National-225590” (CC0) via Max Pixel
2. “Staphylococcus aureus with pigment” By Microrao – Own work (CC BY-SA 4.0) via Commons Wikimedia