The key difference between Bacillus cereus and Bacillus thuringiensis is that Bacillus cereus is an opportunistic pathogen that causes food poisoning, while Bacillus thuringiensis is a bacterium that is commonly used as a biological pesticide against insects worldwide.
B. cereus and B. thuringiensis are two bacteria belonging to the genus Bacillus. They are spore-forming gram-positive bacteria that primarily live in the soil. Bacillus cereus, Bacillus thuringiensis, Bacillus cytotoxicus, Bacillus anthracis, Bacillus pseudomycoides, Bacillus weihenstephanensis, Bacillus toyonensis and Bacillus mycoides form a common taxonomic group called Bacillus cereus group. The bacteria belonging to the above group are highly similar in genotype and phenotype.
CONTENTS
1. Overview and Key Difference
2. What is Bacillus Cereus
3. What is Bacillus Thuringiensis
4. Similarities – Bacillus Cereus and Bacillus Thuringiensis
5. Bacillus Cereus vs Bacillus Thuringiensis in Tabular Form
6. Summary – Bacillus Cereus vs Bacillus Thuringiensis
What is Bacillus Cereus?
Bacillus cereus is a bacterium and an opportunistic pathogen that causes food poisoning. This bacterium is gram-positive, rod-shaped, facultatively anaerobic, motile, beta-hemolytic, and spore-forming. Bacillus cereus is mainly found in soil, food, and marine sponges. When this bacterium grows in the blood agar, it gives a waxy appearance. Moreover, some strains of this bacterium are harmful to humans as they cause food-borne illnesses. Other strains can be beneficial as probiotics for animals.
Figure 01: Bacillus cereus
B. cereus is normally contracted from fried rice dishes that have been kept at room temperature for hours. This bacterium can form protective endospores. The virulence factors of B. cereus may include phospholipase C, cereulide, sphingomyelinase, metalloproteases, and cytotoxin K. Generally, at 30o C, B. cereus population can double in as little as 20 minutes to as long as 3 hours. This reproduction rate totally depends on the food product. This bacterium is highly reproducible in milk, cooked rice, and infant formulas. Furthermore, B. cereus is also pathogenic to multiple aquatic organisms, including Chinese soft-shell turtles. In addition, B. cereus is also used as a bio fungicide against Fusarium verticillioides.
What is Bacillus Thuringiensis?
Bacillus thuringiensis is a gram-positive bacterium that is primarily soil-dwelling. It is commonly used as a pesticide worldwide. This bacterium is also found in the gut of the caterpillars, various types of moths and butterflies, on leaf surfaces, aquatic environments, animal feces, insect-rich environments, flour mills, and grain storage facilities.
Figure 02: Bacillus thuringiensis
During sporulation, many Bt strains generate crystal proteins known as delta endotoxins. These toxic proteins have insecticidal actions. Therefore, these proteins are used as insecticides by incorporating them into crops. Genetically modified crops such as Bt corn has Bt genes that are capable of producing endotoxins. However, the use of Bt toxins as insecticides by incorporating them into plants prompted extensive evaluation of their safety for use in foods and potential unintended impacts on the environment.
What are the Similarities Between Bacillus Cereus and Bacillus Thuringiensis?
- Bacillus cereus and Bacillus thuringiensis are two bacteria in the genus of Bacillus.
- Both bacteria belong to the Bacillus cereus
- They are spore-forming gram-positive bacteria that primarily live in the soil.
- Both bacteria can be used as biopesticides.
- They are genetically and phenotypically very similar.
- They both can be grown and identified in blood agar.
What is the Difference Between Bacillus Cereus and Bacillus Thuringiensis?
Bacillus cereus is a bacterium that belongs to the genus Bacillus, which is an opportunistic pathogen that causes food poisoning, while Bacillus thuringiensis is a bacterium that belongs to the genus Bacillus, which is commonly used as a biological pesticide against insects worldwide. Thus, this is the key difference between Bacillus cereus and Bacillus thuringiensis. Furthermore, Bacillus cereus is used as bio fungicides, while Bacillus thuringiensisis is used as bioinsecticides.
The below infographic presents the differences between Bacillus cereus and Bacillus thuringiensis in tabular form for side-by-side comparison.
Summary – Bacillus Cereus vs Bacillus Thuringiensis
Bacillus cereus and Bacillus thuringiensis are spore-forming, gram-positive bacteria that primarily live in the soil. Both bacteria belong to Bacillus cereus group. Bacillus cereus is an opportunistic pathogen that causes food poisoning. Bacillus thuringiensis is commonly used as a biological pesticide against insects worldwide. B. thuringiensis produces toxins that are toxic to a wide range of insects unlike B. cereus. So, this summarizes the difference between Bacillus cereus and Bacillus thuringiensis.
Reference:
1. “Bacillus Thuringiensis (Bt).” National Pesticide Information Center.
2. “Bacillus Cereus.” BC Centre for Disease Control.
Image Courtesy:
1. “Gram stain of Bacillus cereus” By Joe Rubin (CC BY-NC-SA 2.0) via Flickr
2. “Bacillus thuringiensis” By Dr. Sahay – Own work (CC BY-SA 3.0) via Commons Wikimedia