The main difference between Bacillus and Clostridium is that Bacillus grows under aerobic or anaerobic conditions, whereas Clostridium grows only under anaerobic conditions.
Clostridium and Bacillus are two distinct genera in the phylum Firmicutes. Both are gram-positive bacteria capable of forming endospores. In addition, these bacteria display a characteristic rod-like shape. Although they belong to the same phylum, Clostridium and Bacillus differ in their class, order, and family classification. Therefore, they also have some different characteristics.
Key Areas Covered
1. What is Bacillus
– Definition, Features, Growth
2. What is Clostridium
– Definition, Features, Growth
3. Similarities Between Bacillus and Clostridium
– Outline of Common Features
4. Difference Between Bacillus and Clostridium
– Comparison of Key Differences
Key Terms
Bacillus, Clostridium
What is Bacillus
Bacillus is a gram-positive, rod-shaped bacterium. This rod shape is due to the significant change in pressure on cell membranes, pushing the cell wall into a rod shape. It is a member of the phylum Firmicutes, class bacilli, order Bacillates, and family Bacillaceae.
Bacillus is an aerobic or facultative anaerobic bacterium. It frequently occurs in chains. Furthermore, Bacillus bacteria form endospores. These endospores become dormant under adverse environmental conditions and remain for longer periods in that state till the necessary conditions for growth arise. Moreover, these endospores are resistant to heat, chemicals, and sunlight. Bacillus bacteria live in almost every natural environment. Bacillus bacteria generally divide in the same plane and are solitary. Sometimes, they combine to form diplobacilli (two bacilli arranged side by side), streptobacilli (bacilli arranged in chains), or palisades. Some bacilli are used in agriculture, as insecticides like Bacillus thuringiensis. Some bacilli are pathogenic. For example, Bacillus anthracis causes anthrax disease. Some bacilli are also associated with food poisoning. These bacteria secrete catalase.
What is Clostridium
Clostridium is a rod-shaped, gram-positive bacteria. They belong to the genus, Clostridium, order Eubactiriales, class Clostridia, and phylum Firmicutes. They are found in soil, water, as well as in intestinal tracks. Furthermore, they are anaerobic microorganisms, meaning that they only grow in the absence of air. The sizes of variants of bacteria vary widely. The dormant cells are highly resistant to desiccation, toxic chemicals, detergents, and heat.
Most Clostridia are fermenters. This is why Clostridium is used in the production of alcohol and commercial solvents in the industry. Clostridium is also helpful in cancer therapy. Though there are several beneficial aspects of Clostridium bacteria, there are some severe harmful effects as well. Some types of Clostridium cause different diseases, some of which can even be fatal. The most common infection of Clostridium is gastroenteritis. Clostridium tetani, a variant of Clostridium species, causes botulism, which is a fatal disease. Clostridium perfringens, on the other hand, cause gas gangrene. In addition, clostridium bacteria cause food poisoning.
Similarities Between Bacillus and Clostridium
- Bacillus and Clostridium belong to the same phylum: phylum Firmicutes.
- They are gram-positive bacteria.
- Both bacteria types also have a rod shape.
- Both are endospore-forming bacteria.
- Additionally, they can be pathogenic and can cause some diseases in humans.
Difference Between Bacillus and Clostridium
Definition
Clostridium is a gram-positive bacterium belonging to the phylum Firmicutes, class Clostridia, order Eubactiriales, and family Clostridiaceae, whereas Bacillus is a gram-positive bacterium belonging to the phylum Firmicutes, class bacilli, order Bacillates, and family Bacillaceae.
Growth Conditions
Bacillus grows under aerobic or anaerobic conditions, whereas Clostridium grows only under aerobic conditions.
Spore Shape
Bacillus produces oblong-shaped endospores, whereas Clostridium produces bottle-shaped endospores.
Secretions
While Bacillus secretes catalase, Clostridium does not secrete catalase.
Diseases Caused
Bacillus can cause food poisoning and serious diseases like anthrax, while some types of Clostridium cause diseases like botulism, gas gangrene, and gastroenteritis.
Conclusion
In brief, Clostridium and Bacillus are two gram-positive bacteria capable of forming endospores and belong to the phylum Firmicutes. The main difference between Bacillus and Clostridium is that Bacillus grows under aerobic or anaerobic conditions, whereas Clostridium grows only under anaerobic conditions.
Reference:
1. Turnbull, Peter. “Chapter 15 – Bacillus.” Medical Microbiology. 4th edition. National Library of Medicine.
2. “Clostridium – Overview.” Science Direct.
Image Courtesy:
1. “Bacillus subtilis Gram” By Y tambe (original uploader) – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Clostridium acetobutylicum” By Geoman3 – Own work (CC BY-SA 3.0) via Commons Wikimedia
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