The key difference between Bacillus and Clostridium is that Bacillus is a genus of gram-positive bacteria that grows under aerobic conditions, produces oblong endospores and secretes catalase while Clostridium is a genus of gram-positive bacteria that grows under anaerobic conditions, produces bottle-shaped endospores and does not secrete catalase.
Clostridium and Bacillus are two genera belonging to phylum Firmicutes. They are gram-positive endospore-forming bacteria. Moreover, they are rod-shaped bacteria. Though they belong to the same phylum, their class, order and family are different. There is also a difference between Bacillus and Clostridium based on the shape of the endospore, aerobic and anaerobic conditions, and the secretion of catalase enzyme. Bacillus spp are aerobic bacteria while Clostridium spp are anaerobic bacteria. Therefore, Bacillus spp thrive in the presence of oxygen, while Clostridium spp thrive in the absence of oxygen.
CONTENTS
1. Overview and Key Difference
2. What is Bacillus
3. What is Clostridium
4. Similarities Between Bacillus and Clostridium
5. Side by Side Comparison – Bacillus vs Clostridium in Tabular Form
6. Summary
What is Bacillus?
Bacillus is a genus of phylum Firmicutes. They belong to the class Bacilli, order Bacillales and family Bacillaceae. They are aerobic bacteria that are gram-positive and rod-shaped. There are more than 266 known Bacillus species in this genus. Bacillus species produce oval-shaped endospores. Due to these endospores, Bacillus species can remain dormant for years. Bacillus species degrade organic matter in the soil.
Some Bacillus species are pathogenic. B. cereus causes food poisoning, while B. anthracis causes anthrax. Some Bacillus species are useful in agriculture, especially B. thuringiensis and B. sphaericus are used as insecticides.
What is Clostridium?
Clostridium is a genus of anaerobic bacteria. They belong to the phylum Firmicutes. Moreover, they belong to class Clostridia, order Clostridiales of family Clostridiaceae. They are gram-positive, rod-shaped bacteria that are fermentative and endospore-forming. Clostridium produces bottle-shaped endospores. They do not secrete catalase. There are around 250 Clostridium species. They can be free-living or pathogens.
Clostridium botulinum (food spoilage (especially canned foods); botulism), Clostridium perfringens (gas gangrene), Clostridium tetani (tetanus) and Clostridium sordellii are four Clostridium species that cause human diseases. Certain Clostridium species are useful in the industrial setting. C. acetobutylicum is used to manufacture butanol.
What are the Similarities Between Bacillus and Clostridium?
- Bacillus and Clostridium are two genera of rod-shaped, usually gram-positive bacteria.
- They are spore-forming bacteria.
- They are members of the phylum Firmicutes.
- Bacillus and Clostridium are often described as Gram-variable.
- There are pathogenic species in both genera.
- Certain species of both Bacillus and Clostridium cause food poisoning.
- Moreover, some species of both genera produce toxins.
What is the Difference Between Bacillus and Clostridium?
Bacillus is a genus of aerobic bacteria, which produces oblong endospores and secretes catalase, while Clostridium is a genus of anaerobic bacteria, which produces bottle-shaped endospores. So, this is the key difference between Bacillus and Clostridium. Besides, Bacillus species belong to class Bacilli, order Bacillales, and family Bacillaceae, while Clostridium species belong to class Clostridia, order Clostridiales, and family Clostridiaceae.
Moreover, another difference between Bacillus and Clostridium is that Bacillus species secrete catalase, while Clostridium species do not secrete catalase. Also, Bacillus forms oblong endospores, while Clostridium forms bottle-shaped endospores. This is also an important difference between Bacillus and Clostridium. Furthermore, Food poisoning and anthrax are some diseases caused by Bacillus while botulism, gas gangrene and tetanus are caused by Clostridium.
Summary – Bacillus vs Clostridium
Bacillus and Clostridium are two bacterial genera of the phylum Firmicutes. They are gram-positive endospore-forming bacteria. Bacillus species are aerobic bacteria that produce oval-shaped endospores. Moreover, they secrete catalase. In contrast, Clostridium species are anaerobic bacteria that produce bottle-shaped endospores. They do not secrete catalase. Both genera include bacterial species that cause food poisoning and other human diseases. So, this is the summary of the difference between Bacillus and Clostridium.
Reference:
Image Courtesy:
1. “Clostridium botulinum 01” By Y tambe (original uploader) – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Bacillus subtilis Gram” By Content Providers: CDC – This media comes from the Centers for Disease Control and Prevention’s Public Health Image Library (PHIL) (Public Domain) via Commons Wikimedia